Welcome everyone to the session Repairs Safe while Continuing Operations Theory of Constraints by Wolfram. We are glad Wolfram could join us today and he has joined us from Germany. Wolfram is the founder of BlueDolphin.world and his purpose is to make the knowledge how to reach high performance in shortest possible time available for all organizations. Today he will share his experience in overcoming problems in safe implementation to generate float 2.0. We are very excited to hear that Wolfram. Yeah, thanks a lot and I'm very happy to be abroad in India. So hello world, hello India and maybe a very few words to me so you can a little understand who's talking here about safe and repairing safe. My name is Wolfram Müller and I'm an engineer so very technical driven software developer and I was responsible. Maybe you know the company one and one dot com an international internet service provider worldwide active and I was there responsible for the project management office. So I was responsible in my time there for over 500 product developments and projects with a lot of people for the project manager thousands of developers around the world. So and you can imagine internet internet service provider. It was a very, very interesting dynamic time. And we had to react very fast. So we started in 2002 20 years ago already with agile. And you can believe me we did all the mistakes you can do. And once in this, delivering all the projects and products, we came to this idea of theory of constraints. And it was really a breakthrough for us in performance. And after that, I started, of course, to distribute this knowledge you heard about the blue dolphin. And we are now something around 70 people around the world, supporting companies who want to reach this hyper productivity. The best thing part is, since a year, more and more companies are coming to us with the question are we implemented safe. And the safe is not perfectly working in the way we expected it. Therefore, we are asked to support and help to repair this. And I will to show you a little how theory of constraints can help you in this. And as mentioned below in the screen you see the URL and the code, and I would invite you to open a browser a handy or something like that. Then you see the screen here and you can give your feedback and answers and stuff like this. So to have a little more interaction in this session. So, and you can forget about everything, unless you remember theory of constraints, because that is the main key and the main idea to get hyper productivity. So, and now the first, the first test whether Mentimeter is working and to get a little warm with it. What is your experience with safe, you heard about safe maybe you are part of a safe implementation. And now you can vote. What is your experience, got it worse. Was it more or less neutral. Yes, it felt good. And as you heard we are talking or I'm often talking about hyper productivity, and we talk about hyper productivity. If you reach factor two to five more throughput. So really breakthrough throughput and reduction of lead times by 50% and more. So, yes. As you see, it obviously works meant to be it is working. We get the first boats in. So, and it's, it's a very typical picture we see right now. Yeah, sometimes it get worse but but your experience is not like this. It's, it's very often very neutral. So normal, nothing really big breakthrough. And yes, of course quite some organizations feel that they get more agile and that's fine that's that's a main idea, but to be honest, there is no breakthrough. So and that's, that's one of the things, and we are, we got caught of course from the blue ones, very good war worse. And that's my experience what I want to show here. Okay. Thanks you a lot. So many meter works, and you're already familiar with. And now I will have free questions and slides, because very often consultants are telling you oh you have to do this and that and then everything and I don't believe in this. We are believing in assumption and physics of flow. And therefore I just want to check you check with you a few assumptions we have about the world. And you just have to vote yes or no whether it fits for you. And I just explain it shortly. So, and the first assumption we have the goal of an organization has to be generate more outcome. And I already the difference between outcome and output output is just putting something out outcome is, if it is valued by the customer, and if it's valued by the customer, then he wants to pay for it. And then there is value for the customer what do you think is this a valid goal for companies, and you are completely clear. And I love it, because that's a main main main breakthrough and idea really to generate more outcome and if outcome is generated, the company will prosper and grow. So and that's the first part. Thank you for this. Now it's getting a little more tricky. You already heard the theory of constraint stuff. And there's one assumption. And we have one assumption that it's impossible that there are independent value streams. And I showed their picture on the left that are streets by night. And of course you could build streets from every house to every house without intersection. But that's very resource intensive and, and in the end, the fun of a network are the intersection where you can change the roots and make shortcuts. So we believe that it's impossible to have independent work streams. You already see in the voting. That's not so clear because a lot of consultants say you have to have independent streams and independent teams and to end. But in the end, all the breakthrough innovation are across. So just for you, our assumption is that streets are interconnected, the internet is interconnected. And even the value streams are massively interconnected in a company. Otherwise, they would be two companies. Okay, thanks a lot. So now the next question. It's getting harder step by step. If you have such an interconnected network. If you have that theory of constraint, then there will always be a constraint. So one interconnection should be the hardest of all. And my question is how many of the constraints you know in a company. And this is interesting the voting. Oh, that's going in the wrong direction, by the way. So, but that's, that's the key part. And therefore I just can say, have a look in the theory of constraints and the interesting part is, the constraint assumes and we've seen that in practice. There is, there is always one constraint that is harder than all the others. And this one constraint rules all. And if you find this constraint, every in everything in management gets very easy because you just have to focus on this. Okay, so you heard it. Our concern, our assumption is there's always one constraint and you have to find it. And on the left side you see the picture of an airport. And there's very clearly one constraint it's a runway, and it's everywhere in the world the same. And in it organization, it's very often architecture business engineering, or if it's not so mature, then it's deaf ops and stuff like this. So, keep aware, there's always just one constraint in a system. So, thank you a lot. And now back to safe. Now you can give your statement on a scale. What do you think how good is safe fulfilling the goal to improve outcome. Well, the second scale is. What do you think does safe works perfect in a very complex value network with a lot of interconnection. And the last one is in safe environments. Do you see this constraint. It must be very, very, very obvious and visible. I'm a little, little interested in what you think. Oh, it's something in between. So the goal stuff is fulfilled. Yes, I think so too. That's, that's clear. Safe has the same goal than we. It's interesting that you think that, that the, the constraint is visible in safe, and it can deal with complexity. There we will have a look at it. So, I'm a little surprised because we see a lot of trouble in safe working with the dependencies. And of course, we don't see the constraint in there. Okay. Fine. That's always interesting to have a vote. Thank you for this. Now we go a step deeper. So that that were the assumption. We're going one step nearer to the solution how to repair safe. And 10 years ago something around that I learned about self organization, and not the classical standard way of self organization by the scientific approach of self organization. And that's very interested how ends and organizations and physical systems are, are organized. And in the end, it's very, very simple. It must be simple otherwise it would not be a success story self organization. And in the end, you just have two principles or factors that decides whether you are successful or not. And the first one is very strange. The first one is very strange. All living organizations are under loaded. And that's a very, very, very important pre condition. And you voted for, oh, there are more constraints. And very often. This is a effect. If you are overloaded as organization, and you see of course more constraints, then it looks chaotic. If you are under load the organization you will clearly see your constraint. So that's a very important precondition. And the other one is having a strong very fast transparent signal, so that everyone knows about each other and what the state is. So he can decide in a way that's good for himself and for the organization. And that are the main, main points. If you want to use self organization in a positive way, you have to fulfill these two principles. So now this is very abstract. And therefore I just took out my pen and sorry about my drawing ability is not so good. But I tried to paint a crossroad, like in the example before. The first question you always have is, where is my constraint. And this is a simple, simple example, of course, so you immediately know where the constraint is. It must be the area of the crossing, the crossing area, because there are just one or two cars can be in and on the streets, you have at least four times more capacity. So in the cross section, it's always this area where the streets are crossing. Okay, that's clear. And then the next question is typically. Okay, if I have a constraint, I will, I will use it 100% that's the optimum. So what happens if you really reach 100% usage. Very often it is called traffic disruption. But the bigger problem is, if anything happens, and you are fully loaded, what happens then you will never be able to recover.  So it's not a good idea to load the constraint at 100%. But what is acceptable, and maybe you know queuing theory and stuff like this, it depends a little on the fluctuations, but more or less a rule of some. I think around 80% is already much to recover from any, any incidents and stuff like this, bugs or misunderstandings. So 80% is a good, good number for the planned load of the constraint. And then the next question is, okay, if what is the acceptable average load in the inflow then of course. The testing part is that it must be even below that, because otherwise if a problem occurs somewhere else, it's also not able to recover. And if it's more inflow than the capacity of the constraints over the long run, you will have a huge backlog, and the lead time will go down. So therefore it's so important to really understand this principle of self organization, you have to under load the organization. And now that means and if you work with C levels, we often let them speak out loud the sentence, resources have to wait for work. So if you really want to have a flowing system, then the people, the developer or whoever, they have the ability to do their job, and then they wait shortly, not very long. And then the next work package comes, and that means the work is flowing in optimal speed and optimal speed means optimal outcome. You have optimal time to market. So, I'm the loading the system is a precondition for really hyper performed organization. It's not hard to sell, but it's a precondition. So, that was principle one, and principle two is the transparent signaling. That's a little more complex. But the question is always, if you do not have a transparent signaling, what will happen, all the cars will run into the cross section, it will have a traffic jam, and the output is nearly zero. The next thing is, is it possible to manage such a system if everyone just knows his car and nothing about the others. It's not possible, even in a self organized system, you need a very fast signaling system, where all the cars are to decide whether you can go into this cross section or not.  So, there must be something like a starts control. And in a cross sections easy to traffic light. And you can believe me, all traffic lights are centrally controlled. That means there's somewhere a computer, he has an overview where the cars are. And they, they do with the traffic light, they do with the starts control. So it's nearly impossible, as I say nearly to negotiate the right, the right inflow, because the local and egoism prevents to really get the optimum. And that's the last question or the second glass question, what's the core of this starts control, and that it's not directly the flow in the cross section, but it's a queue length. So all the modern traffic light controls, look at the cues, and the longest queue will get more resources of the constraint, so that the overflow, the overall flow is smooth. So it, and as I said, it's a more, it's a little more abstract. But, but it's very important to know that if you unload the organization, then you still have the need of a some kind central signaling system, a very light white ones, a very fast ones to really get the starts control done in a way so that everyone gets the precious constraint resource. And the last question is, okay, if there are just two cars, such a signaling makes no sense. And if it's completely overloaded, then it makes also no sense. So it's connected, you can't have a good signaling system in an overloaded system, it makes no sense. So these both principles are very tightly knitted together. So, wow. Sorry about this section. That is the base that are the principles you can read about this. That's a base of all what we are thinking. My question to you, does these two principle make sense to you. Are they reasonable. Wow. Good, because the interesting part of this is, you can look at whatever system. You will find these two principles in our body in until in the traffic system in companies. These are universal systems for all living beings and organizations. So it's very important to understand. And the hardest part is of course, the underloading. But that's a key for hyper performance. So in the, the next question is, okay, you have a little experience with safe. environment really like this, that resources are waiting for work. Is it in a safe environment really like this, that every day, everyone knows where his story is what the end and the start date, and what the status. Every day, I'm talking really about every day. And I'm talking about resources are waiting for work. Interesting. I thought this is more clear. And then the voting would be more clear but it's, it's interesting for me also to have such motifs to learn about. Now I would would be interested in having a discussion why you think that there is every day signal. We have, I learned afterwards a hangout possibilities so we can discuss about this further, but the under load. That's a real problem of safe because everyone pulls in his PI planning or whatever, and they are all 100% working all the time. So they are not waiting for work.  And the signaling. Yes, it's there of course on the team layer, but on the on the coordination layer and on the portfolio layer. So on the overall portfolio. It's not very clear what my story has as a status for everyone else. So and now it's all about fixing this. As I said, since the year more and more safe implementations are coming to us. We have now a list of 19 fails and stuff like this. And what we see is safe is very, very clear in the goal, a more outcome. Many consultants are telling the people that it's very important to have independent teams and value streams and to end but this is seldom the case. The constraint is not visible. It's not clear who is constraining the output of the overall system. And if everyone pulls work, everyone is busy. So you will see, of course, then many constraints, a lot of discussions about priorities and dependencies. And sorry, I don't see a team over spanning signaling where my story is. So on the coordination layer, the only thing you have to do or can do is talk. So, sorry, that was the safe bashing part. I don't want to bash safe. It's, it's fine, but it had it really has to be improved. And now that's, that's, I think the most critical or hardest question. If you all have the job to, to repair such a situation, then you have different possibilities what you can do first. So you can do first optimize the flow in the team. Now you can first implement dependency or coordination management, you can implement lean portfolio management. And my question to you is, if you have the job to save, save. What do you think should be done first. Wonderful. Okay, that that I really like. And because I think safe is not so bad at all. But they do the stuff in the wrong order. So when we are working with companies to get hyper productivity, the first thing is to identify the constraint and the organization. And then you have the head free for change and doing new stuff. The second thing we are doing is the signaling. So, so you rated the dependency and project management as third one, we, we typically use this as a second one. And then if you have the signals and the under load, then it makes absolutely sense to optimize the flow in the team. And now, now I just want to show you for concepts out of theory of constraints I don't want to go so much in detail. But just to give you a short impression about this. And afterwards I show you where you can get more, more details. But when we are going into a say for any other organization. The first thing we are doing is we activate the lean portfolio management, but not in this general term, like described in safe, but really based on the theory of constraints.  We, we put them on a list. And the customers or the organization put some low data, very rough estimation what skills they need and how much of them, then you simply add every needs. And you compare it to the capacity of the skills. And then you have the constraint identified. That's a picture in the left above. So these are the queue length. And if the demand is over the capacity, then it's get read.  So it's a real decision hard decision to cut the overall strategic backlog down until the constraint is in the under load. So that's that's what we are calling freezing after the freezing you you have a little more information. You see where you're where you have capacities. And by the way, Skype did it a few years ago. And they found 50% spare capacity by doing this. And then of course you readjust your team sizes so that the constraint is better loaded the pictures below show the roadmap and the red stuff is always the constraint usage. And the game is all about not overloading the constraint. And if you don't overload the constraint, every other team is not overloaded, very typically teams are loaded with 50 to 60% plant load. And that also allows them to do sharpen the X to improve the way of working learn so protective capacity spare capacity is not bad at all. It's necessary to evolve and increase flow. So, if you do this, the constraint is an under load and all other teams have spare capacity. You can't imagine, if you do this, and we did it 35 times. It's already a completely different organization you have. So the next thing that's a little more complex. Sorry about this. And maybe you read the first book of David Anderson. We have introduced the concept out of theory of constraint called ground buffer rope. Then the book of David, a lot of things has evolved. So, we are using this simplified ground buffer concept for cues. And if you look at a safe installation implementation, each team looks like ordered queue of deliveries. And each of these items has, we call it standard lead time. So if it is the only thing to do, it takes maybe a week or two week or something like that. And this queue that's a picture above, you just put everything behind each other.  So, and even new items coming in, you can easily say when you have to stay a start and stop when you can deliver. So this is a very simple heuristic about determining for each item at you date. So, and we did it with Steve kind of together with a four and a half thousand developer company 120 teams, easily to do. And then everyone knows about start and end dates of his item. And the goal is to deliver in yellow. So if an item comes to read, someone takes care. And this we call expediting. And out of the expediting you learn what's what's the problem. And then you can fix the process. If there are too many items finished in green, then you reduce the lead times. So and the, the success story of this is no one has to ask. So you don't need to have a PIP planning. Everyone knows when his items are coming and you do the screen read yellow stuff and expediting, you really can be sure that it is delivered. And that's about this. So there are much more details afterwards you can request. And if you have for each story at you date, then you can do a very simple project management on top. That is the middle layer that is very complex in in say if you have to talk a lot to manage the dependencies with a drum buffer row below. It's very simple. So for example, if you have a small bigger release epic or strategic delivery that contains maybe three stories in three different cues, and they have to be finished at the same time. Then you simply can look in the cues where your parts are. And you just take the last delivery date and then you know when the overall is delivered you can also build dependencies. And that's a very, very simple way to do project management you simply have to look where your parts are.  And then you can talk with him, and he's willing to postpone his part. You can easily do decisions trade offs. And it's very easy to get a reliable due date for even bigger complex deliveries with many parts. We've done this to in many companies. And the idea is really and you can do it all the time. You have all the data all the day. And this leads to a very simple preparation of pips, because everyone already knows everything, the dependencies, the due dates, and then you simply have to talk about the strategic strategy about the context and all the stuff around, but not solving these dependencies, because they are already solved. And the last fix for the last part is this flow in teams. Maybe you realize that Steve tendon in three hours has also a speech here together with Steve tendon I wrote the book tame the flow. And it's all about the perfect flow in teams. And that's very simple.  I prefer the swim lane version with planned in progress and finished. And the only thing you have to do is to take care that less sub tasks are open then people in the team. Everything else makes no sense in a knowledge working environment. And if something is not able to flow or is there a problem. If it's internal or external problem, you don't have to write an impediment backlog or scrum master to ask for anything like this. I really prefer pull the line stop working on on anything else fix the problem. And by doing this you will really get very fast into very good flow if you solve your problems. If you solve the problems then reduce the sub task size so that the problems will occur faster and more until you really reach perfect flow. And if you have the drum buffer of stuff. So you have a traffic light system. And typically you put this traffic light also on the Kanban board or whatever. So you have a priority. And of course, if, if there is a red line, then please help the people in the red, and you will have optimal flow within days. That's the last fix we promote really reduce the work in progress on team layer, layer less sub tasks, then people in the team, no backlogs no blocking areas, pull the line and fix the flow. So that were the four, the three. No, that are four fixes. And as I said, we do it very often. So, just imagine an organization that is in under load, would you love it, or an organization where everyone knows about every story, the status and the due date, very easy to manage, or an organization where the teams are in perfect flow. So, would you love it or not. Okay, that's interesting. I have to talk afterwards with the one who voted for he does not love an underloaded organization. Okay, so you, I think you get the idea. I really can tell you, we have a lot of testimonies when people came to us and said, Oh, it's so wonderful to work in an organization that is in under load. It's so so relieving. So, where the stuff is. And I really am astonished, working in a team with perfect flow. I really can wish you this, because that's the most wonderful thing, and the team that is in perfect flow and has no hurdles. There was a creativity that that is unbelievable. So, but you're a little on the right side, you're not so happy and in love with the stuff so I have to think about, and maybe in the hang out you can tell me why. And that's it. And it's no fantasy of mine. We do this in 10 years. And just to give you a small impression, one of the biggest was telephonic Brazil with x 1000 employees with this ideas. They doubled the throughput. Other companies like Bush, they reduce the time to market by 35% up to 70% even after five years doing lean. So, and, or for example mega within 20 weeks, they quadrupled the output and wasn't how's more or less the same. So we have a lot of experience 35 companies and a company that's in flow that's also good for the people and the creativity comes back. It's unbelievable all these companies are now more or less market leaders in their area, because they are simply faster than all the others. And just just for you here a little the overview. And the main thing is, we pulled the portfolio management in the implementation of safe in the front in the beginning. We do this queuing stuff and this project management stuff to get the easy, easy dependency management, and then of course, in the coaching area, we really think and help the teams to reach flow, and that's it more or less. So that was it from my side. Thanks for your time and it was too short to show you everything of the last 10 years we did. So here are five links. A lot of resources everything for free. You just can grab it and use it there are tools everything you need to know. And the last thing is, I love India. I really do it and we also have dolphins and supporters in India. So, if you have question afterwards to me. Thank you so much for your time and I will be happy to answer your questions of course too. So, thank you. That was it from my side. Thank you will from wonderful session. So much to digest. Sorry. It's been wonderful. We, we only have like two minutes so maybe we can take one question now and then remaining we can take in the hangout. So there is a question that asks in an organization there can be more than one constraint is what I have seen. Of course one could be predominant. So why do we say that there is only one constraint. There can be two or more, but it makes it very, very complex. And it's, it's as the question I said there's a predominant one. And if you want to grow as an organization, then you have to focus on the most severe one. And therefore we say, there's always one that dominates everything. If you solve this, then you have of course the next one. So, yes, there are in reality more than one, but the idea is to have one and focus on one, and then the next one. Makes sense. Yeah. And thank you so much will from for sharing your experience with us today.


My name is Adrienne Meneses and I am an immigration attorney as well. I work at St. Mary's Center for Legal and Social Justice in the Immigration Human Rights Clinic. I'm one of three attorneys who supervise law students who are learning the practice of immigration law. And we do an assortment of direct representation including deferred action for childhood arrivals for kids who've been here much longer than the kids we're talking about today. Also asylum and some other things as well. I should probably mention that our clinic director, Lee Tehran, is not here with us this morning because she's actually preparing for one of our most contentious asylum cases that's been in litigation for over two years involving three unaccompanied alien children from Central America. Which is actually the topic that I'm going to talk about right now, which is asylum. There's been a lot of discussion about unaccompanied alien children and their pursuits of asylum. And so I'd like to clear up a couple of the misconceptions regarding asylum and regarding the problems that people from that are crossing the southern border face when they come to the US and apply for asylum. One of the most important misconceptions is that applying for asylum is, you know, as people see in the movies where people run into embassies and have their hands in the air and request for asylum. And that really couldn't be anything further from the truth. Jonathan mentioned how important and how significant it is that migrants seeking asylum in the United States have access to lawyers who can help them review their claim. And I'm going to echo how tremendously important that is. Asylum is not a DIY project by any stretch of the law. As I walk through the various aspects of asylum, I want to remind people of a couple of things. One, in any kind of immigration proceeding and certainly including asylum, there is no right to an attorney at government expense, the way you would have if you were in a criminal defense type matter. You can afford an attorney, or if you can afford an attorney, then you can generally have one with you. But do also keep in mind that many of the people crossing the border simply can't afford attorneys or they're being warehoused in detention facilities where they can't realistically facilitate getting an attorney to them. So again, as I'm walking through this, keep in mind that most of the people that we're talking about who are applying for asylum are doing so without an attorney. However, they're opposed by a trained government attorney who is an expert in immigration law and whose job it is is to remove people from the United States. These applicants are dealing with an incredibly nuanced area of an incredibly nuanced area of law. Asylum is one of the most complicated areas of law. Immigration law is generally recognized as being second only to tax law in terms of its complexity. You're also dealing with people who have been traumatized. They've been exposed to terrific violence and they're frequently still recovering from that. Most of them have not had access to any kind of psychological services to recover from that. They're dealing with nuanced laws in a foreign language and most of them have very little education and in some cases are functionally literate in any language at all whatsoever. So you have a person in that situation opposed by this trained government lawyer in a project that should really never be attempted by themselves anyway and you can sort of imagine the outcome. It is important to remember too that and of course when you add this person being a child, you can imagine the probabilities of success. One of the misconceptions and it's really tragic. I wish it was true that I hear all the time is that asylum is widely available to people for whom bad things have happened and that's really not true. In order to be eligible for asylum, the person who's applying has to have been facing persecution as a result of race, religion, nationality, political opinion, or membership in a particular social group. And that's it. Just those five what they call protected classes. If you're facing persecution on one of those grounds and you may have an avenue for asylum, if it's for any other reason then asylum is simply not available to you. The burden is on the applicant to show that he or she meets all these eligibility requirements. It's not on the government to prove otherwise the way it would again in a criminal defense matter where someone has to prove you're guilty of a crime. No, you the applicant have to prove that you meet these eligibility requirements. Another misconception, and this isn't specific to asylum, this is specific I guess to broader immigration, is that words mean what they normally mean. If only words and immigration law meant what they mean in the dictionary but unfortunately they don't. It's extremely nuanced terminology and so going back to these five protected grounds, race and nationality are fairly straightforward, religion slightly less so. But let's look at membership in a particular social group and political opinion. When people hear social group, they think a softball league or a youth group and they don't describe themselves in those terms and when they think about the bad things that are happening in their lives, they don't think about it in terms of I'm being persecuted because of my membership in a social group. And so when they're being interviewed by asylum officers and they deny their membership in social groups because they don't know that's what they're talking about, then they lose their opportunity to apply for asylum on those grounds because they really don't know what the asylum officers talking about. So for instance, these are two social groups, I'm going to tweak the names here a little bit obviously to protect the confidentiality of my clients, but these are two social groups that I have used successfully in asylum cases involving unaccompanied kids. Number one, unprotected Mexican children in a nuclear family or imputed nuclear family of women who have had a domestic relationship with Jonathan Ryan. Now, I would hazard guess that applicants are unlikely to describe themselves in those terms when asylum officers ask, have you been persecuted on account of your membership in a particular social group? But that's what the law is asking for. Another one, unprotected Mexican children in a nuclear family or imputed nuclear family of individuals involved in Mexican drug dealing or drug trafficking activities who have acted in a manner inconsistent with their cartel gang supervisors or associates or rivals. So you can see why it's so crucial that these applicants have access to lawyers who, like myself or better or worse, have taken this on as our chosen field of practice and who know how to frame these claims. If you listen to what I was talking about, those are fairly common claims of domestic violence in the home and fear of cartel gang violence when you have family members that are involved, but how you frame that fear and how you frame who's going to hurt you, and most critically, how you frame why that person is going to harm you is vitally important to the ultimate success of your asylum application. And again, it's incredibly important that you have a lawyer or some other kind of legal representative to at least explain this process to you and what this terminology means. So basically running through the timeline of an individual who's apprehended in the United States and then seeks to apply for asylum, when an adult, we'll talk about children in a second, when adult is apprehended in the United States, if she or he gives any indication at all that she has a fear of returning to her home country or intends to apply for asylum, she's supposed to get what's called a credible fear interview with an asylum officer. If in that interview she's able to articulate that she has a credible fear of return, I'll talk about that again in a second, she's supposed to have an opportunity to present her case to an immigration judge who will ultimately decide whether or not she meets the definition of refugee and is eligible and deserving of asylum in the United States. Now, this credible fear interview, she doesn't have to prove her case at this point, just establish that she has a credible fear of return. She's credible, she's believable, and she's articulating a fear that could, has a significant possibility of providing the grounds for a successful asylum case. That's all you have to do at the credible fear interview phase to get your case taken before a judge. That doesn't mean it's granted. That just gives you the opportunity for your day in court. The way it's supposed to work is that trained asylum officers are supposed to conduct these interviews in a non-adversarial setting with only the persons that the applicant wants present, and that could include a lawyer. The officer is supposed to ask as many probing questions as necessary to ferret out those claims like those ones I was just describing to elicit all the information that he or she needs to make an honest, unbiased, unprejudiced determination about this person's claim. And if the applicant is too exhausted or sick or traumatized, then they're supposed to reschedule the interview to a time when the applicant can have a reasonable conversation with that asylum officer to present his or her case. And if the asylum officer still doesn't find that the applicant has a credible fear, then the asylum officer is supposed to allow the applicant to discuss his or her claim again with the judge, and then the judge will decide whether or not the applicant gets a full hearing. That's the way it's supposed to work. And overall, 77% of asylum seekers generally pass the credible fear interview stage. Again, that doesn't mean that they win their cases far from it. That just means that they get their day in court before a judge. Unaccompanied kids are handled differently. Unless they're from Mexico or Canada, regardless of whether they express a fear of return, they're given an opportunity to present their case to an immigration judge. And that's where organizations like RAISIS come in and are so vitally important because our lawyers are able to come in and talk with kids. And they have years and years of experience dealing with traumatized children who maybe don't come up and say, I'm a member of an imputed or nuclear family of women that may or may not have had a domestic relationship with some guy. You have an opportunity to talk to attorneys and talk to experts who can help you develop this. The law that Jonathan was talking about possibly being overturned, the TVPRA, is so important for child asylum seekers because it gives them an opportunity to present their claims. And the credible fear interview process is important for adult asylum seekers because it gives them an opportunity to articulate their claims. Unfortunately, right now, adults are being directed to specific detention facilities where they are being rushed through the credible fear process. They are given no notice that the interview is about to happen. A lot of times they're asked confusing questions like, are you a member of a particular social group with no explanation at all of what those questions mean?  Often these interviews happen with no access to legal counsel in advance and frequently they're over the phone. They're not even sending actual people down to look these people in the eye and have a reasonable conversation with them. And so as you can imagine, the percentage of people that are passing the credible fear stage and moving on just to your day in court in these facilities is less than 35% on average. I've got very little time left, so I want to rush ahead to just quickly some statistical numbers about the number of asylum seekers versus the number of people who ultimately, once you get your day in court, these aren't rosy statistics, once you get your day in court of the 2,895 Guatemalans that had an asylum hearing before a judge in 2012, only 222 were granted asylum. Of the 2,900 Salvadorians that requested asylum, only 191 were granted. Of the 1,200 Hondurans that applied for asylum, 93 were granted. Of the 9,206 Mexicans that applied for asylum in front of an immigration judge in 2012, 126 were granted. So we're not talking about high statistics. We're only looking for fairness so that people can get to their shot in court where in fairness they don't have a very good shot. As Jonathan mentioned, this is the law. And these are fellow citizens of the world. They have gone through horrors that, frankly, most of us can't imagine and wouldn't care to imagine. And it is the very least that we can do as a decent nation. And the very minimum, frankly, required by law to allow them a reasonable chance to describe those horrors and to ask for the assistance that the law guarantees. Thanks.


So, we will go ahead with whatever I was describing yesterday and now basically we have to look at the what will be the elements which will be participating in a view IP system. So, first of all let us talk about voice over IP, we will expand this thing on to other kind of media streams also parallely. I think another one which is I know because I have designed that system is and I have classrooms over internet for example, where millions of students or trillions of students can actually attend a lecture. Now, if you can even build up that kind of system, but it is not only audio video, nearly two-party audio video it is possible, multi-party audio video is also possible and there is possibility of actually using live chat, there is possibility of tracking how many people are there, there is to be somebody who will be master who will be controlling and people will join the session, they will leave the session, they will raise their hand, they will ask questions, there I might actually conduct a live poll in a classroom, I might give a demonstration or a lot of interactive activity which is possible. Now, this is all together different kind of media streams which are viable. Now, when the SIP or the session initiation protocol was designed, it was you have to design a protocol, now forget what is SIP, suppose we have to design a session basically a mechanism by which any kind of this media session or interaction session can be created among any number of people. So, the idea is basically how this can be created, I need to build up an infrastructure through which this kind of setups, this kind of sessions can be identified whether they are existing or not existing and then people can join these sessions. So, as far as this whole infrastructure is concerned is only for initiating you into the session, once you are joining the session you are into that, then this protocol or this mechanism may not work, there might be some other protocol to which you will be handed over. Very simple example is a conference call where there are 10 people who are in a conference and these 10 people when the conference usually done, there will be a master who will be always controlling the conference, he will say now you can talk or you can talk somebody who will be a floor manager, so floor management system is not part of the design for SIP, through SIP you will be joining this thing and SIP will then inform you this is my floor management mechanism, there will be a separate protocol for that. Now, when you will talk you will be using some kind of audio streaming live audio streaming, if it is a video call may be video streaming also, but then what kind of video thing will be encoded or transmitted at what rate, what will happen if there is a congestion, SIP does not bother about it, SIP is, so SIP will only make sure that people join the session appropriately and after that the two peers will negotiate with each other and will do whatever they want and they will communicate. So, technically what we are doing is we are now building up a peer to peer system, so telephony through peer to peer, but this is fine in a futuristic system, SIP is a peer to peer, when two SIP clients are there they talk, they communicate directly into end, but usually there will be problems in the network, so sometimes peer to peer technically is not possible. So, it requires sometimes what you call intermediaries, which have to be because of the network issues like using private IP blocks or when you are behind a proxy or when you are behind a net, so it becomes a problem. So, it requires some intermediary nodes, so we call them reflector in some of the designs, some of the design these are known as super peers or super nodes, some places these are known as proxies and so, but these do exist. Now, what will be the elements? The whole world will not be view IP in Monday, you have to coexist with the existing PSTN and PSTN telephony also has to be connected, that is another requirement. So, you will have a world where we will have a internet, we will have voice over IP clients, so I am now moving one step further and I am now including my PSTN network also into the system and I will also have a PSTN network, PSTN is public switch telephony network, is a conventional circuit switch system in which our telephones are actually connected and you also will have GSM, you might actually have, see do you remember these are also separate networks, they actually override, so this blob might be partitioned two parts interconnected through a conventional PSTN, but this actually technically is a separate network, but it does gate weighing with the PSTN, that is why your landline can call to the mobile phone. Now, this kind of blob is also going to come into the picture and good thing is that this requires only internet protocol, so whether you are using in the lower layer a Y max or you are using 3G does not matter, so far it provides IP connectivity I can use wipe system. Now, how you will connect to the PSTN, I am not bothered about these, so far if I can connect to PSTN I can connect to all these that is my assumption, so there is no direct peering requirement between this and this, this also can be done, but the same device which I am going to put here can actually do this job, so I need a gateway here, this is technically known as media gateway, so when you look from this side all these phones will look like their wipe phones, when you look from this sides all these soft clients, we call them soft client because most of the wipe telephony clients are nothing but software, they can be put on embedded system and we call it a wipe phone, you can actually buy these phones and most of our actually all smart phones have a built in capability of becoming a wipe phone for example, it is just by loading a software. So, this media gateway does this translation activity, now one way is that whatever be the number of phones on this side all of them can be mapped here as wipe phones and I can run multiple instances for signaling for doing peering bit for voice transport or video transport between any of these phone to here and then there the translation will be done and of course, there will be limited capability if it is a conventional PSTN only voice will be there, you might be using a packet switch system all the way for transporting your voice, you might be using a different codec, when you come on to this side this circuit switch system you will be transmitting raw analog audio it is possible or if this can be that 64 kbps what we call this audio which is there TDM stream that can be transmitted then converted to analog at the edge exchange and then your phone can be connected to this, but usually these devices are costly. So, in fact people usually want their own conventional phone because they always are habitual with that even to use that kind of thing some people might connect a small box this is also known as media gateway and then in turn connect their conventional phone on to this, this is also pretty popular system. So, you actually feel as if you are on having a conventional phone you still dial number and everything, but whatever you do this box captures all the signaling it has a built in processor and it does all the signaling everything which is required by wipe and can connect to outside world actually. In fact, there have been a pretty popular system I have actually seen that in companies who is calling from here to United States is pretty costlier if you actually use a PSTN phone. Of course, now it is that cheap the reason is because most of the operators take the call from your PSTN line they actually convert it into a via wipe call and through a media gateway they will transport all the way to the United States or whichever country you want and from there they will again convert into a through a media gateway into their PSTN network. So, long haul communication is not through circuit switching it is through packet switching. So, efficiency is pretty high and call cost can be very small, but interesting thing is that I do not know whether you have seen I have seen this in India people whose relatives are living in United States they usually send them a small box. So, there are many companies will sell them and it is basically a box in which on the one side you can connect the phone it is a media gateway. You bring that box attach in your ADSL modem or Ethernet and once that is done only thing you should not have a proxy in between or netting router should not be netting router is fine, but proxy should not be there in between because it is working over a UDP tunneling or TCP proxy, but if it is STTP based transport is not supported in that box, but now the more advanced boxes may be supporting that. So, even it can go behind a proxy if you can configure proxy user and proxy password. So, what happens the moment you connect this phone this phone the moment that box gets activated will try to register to a server that indexing server of the operator in United States and it is IP connection. So, it can register there it registers there in that registry it will register this particular address as this particular IP address of this box as nothing, but what we call to a phone number. So, the phone which you are having in India actually is having a number which corresponds to US number. So, in US people will think it is a local number, but actually the phone number lies in India the call is routed through WIPE because register for this phone is sitting in United States. So, it has given a different number, but you need not have phone number as I told last time yesterday class it has to be some user idea at the rate domain name. So, if the Vonage is providing this thing I think this is the one company which does that. So, this prefix is automatically added by that phone and then there is a number which is US number which is your choice when you buy that box. Now, signaling people have built up proprietary. So, let us come to the features of the signaling and what all will be required. So, today what I have added is this one extra element which was not there earlier the media gateway. So, I have to handle this media gateway I have to handle these clients through this media gateway I have to handle the soft clients. So, Skype also when you are making a call actually is exactly doing same thing Skype talks through their Skype network with Skype clients there is a media gateway which Skype has put at lot of places. In India I think it is in US they have, but I think India they do not have a gateway because when I dial from Skype client to India I do not get Indian telephone number. So, only problem is the caller ID in that case. So, when you do a dial you dial with a Skype to a phone number you can do it actually if you have bought the credit. So, once you do that so technically this media gateway is running a Skype client. Now, this remember is a proprietary system which must have been built by Skype. Most of the media gateways come on this side with the signaling interface which is either H dot 323 or SIP there are only two standards which are very commonly used. SIP also has two versions what we will be talking about is this RFC 3261. This is ITUT standard and mostly is kind of it is still in use, but most of devices people want only this one this is a open standard by IETF dot ORG. Now, this SIP v2 is only handling session initiation or session creation basically and joining the session process and how you will get to know that to whom to contact. For example, what is your phone number how do you know your friend's phone number that friend must have given it to you or you must have found it on a website or it must have come in his mail thing the bottom of the mail. It is the same way these URI's SIP URI's we call SIP Universal Resource Identifier. So, phone number the equivalent is known as SIP URI. URI stands for Universal Resource Identifier SIP stands for session initiation protocol. Now, this is not the only thing there are many other set of protocols which are required along with this. So, once I will come to this how the SIP actually handles the session setup. Once the session setup is done this client will be talking directly to this usually. Usually in most common practices this will be done in this way, but also there is a requirement for example, tomorrow if this SIP server or that indexing server or register will be managed by say BSNL and Tata telecom or reliance everybody gets a license. So far it is not there, but may be in a half year down the line we will actually have those systems running in India also. Currently it is not permitted. What is permitted in India is only this kind of system. Only thing which is only for call centers I think it is permitted to actually have a wipe system from conventional telephony to wipe conversion that is permitted because they run call centers. For example, for US if you are running a call center this is a US number on which the people are going to make the call. And that call actually is all they were routed over internet all the way to India. So, those numbers which is their panel actually is a US number which is there, but Indian operators just provide them connectivity and they have to actually keep on giving the reports. One of the biggest problem in this case is you cannot tap the signals. If two peers connect directly you cannot tap. If they both agree on some encryption algorithm and the payload itself is encrypted even if you tap the packets you cannot figure out what is there inside. Skype is I think is a pain in enact problem for Indian defense as well as home ministry everywhere because they cannot tap those things. And you might have heard that during that Bombay stuff they were actually using Skype and nobody was knowing what they are talking. And somebody from across the border was monitoring through Skype only. So, it is still a big problem Skype trapping unless Skype company itself basically cooperates. But probably now it is viable because Skype is taken over by Microsoft. Microsoft has an Indian office. So, Indian government can throttle them and make sure they cooperate. Earlier it was not possible Skype was not a company in India. There was no incorporation here, but now it is. So, I do not know what is the current situation. So, home ministry must be taking care of that. Tapping is not possible. So, you require a different kind of mechanism. This is usually not announced, but when you are actually put a tender whenever you buy an equipment it is a mandatory condition and it is advisable that you should put it. You never know when you will you yourself may require it or somebody else in the government may ask for it actually this particular scenario. We require what we call intermediary gateways. This is again a special kind of media gateways nothing great. So, what will happen is I will give an example. For the time being forget SIP server. So, there is an indexing server running. I call it. These are more generic name actually indexing servers. So, most of the peer to peer systems will have either a distributed or a centralized indexing. So, I am assuming it to be centralized indexing server here. So, when they actually this guy I want to talk to this person. Assume is like a Skype kind of client or Google chat kind of client. It will talk to this person and say I want to talk to so and so people. So, everybody updates their status here. So, when this person wants to talk to this guy. So, he will be this guy will inform him that somebody wants to talk and if he agrees to talk to this person. So, it will transfer its IP address to this person. Its IP address will be transferred to this guy. So, they both know each other and then they will start talking to each other. So, the security somebody else will not be able to spoof because the port numbers which are assigned for every communication they are dynamically changing. So, which port number will be used for communication is assigned by this guy register. Once those are done they can just keep on communicating on that basis and can boot a step for more media streams. But this is dynamic this there is no static things. So, they have to keep on informing the port number at which this is active to the register or indexing server. Now, if I want to implement a tapping system how it will be done I want to tap a certain number. So, I require then additional server the way it will be done is this indexing server will know its IP address this knows this IP address. This will also talk to this third guy for media gateway which can create duplicated entities which can create kind of a conference call. Every packet which is passing through this filter is duplicated and can be rooted to something third party. So, usually what will happen is this guy will be informed IP address of this person this guy will be informed and another port number and IP address of this. So, this guy actually will see this IP address and port number is x and this guy will see z as this IP address and port number. So, when they will be talking this media will be passing through this intermediary. An intermediary can be directly controlled not by indexing server there will be a command which has to be given by your NOG or the operators command center and they will control this gateway and they can make duplicates of all the packets and can root to another client where the call actually can be listened parallely or it can be recorded it can be tapped actually this is what is the tapping principle. In conventional telephony also tapping does not mean that you go physically and put your wire and listen what the other persons are talking about this is not the way it is done. So, once you just inform when the call is being rooted through a switch it is just being a copy gets created and copy is also rooted to another number through again a switching path. So, that is how in Delhi there is actually joined wing of three forces which mean to which actually does this particular job all calls can be rooted to them without any issues and from any switch in India. So, these are just remotely configured from the NOG and any call which is passing through they just make a duplication it is rooted. So, this either they do it or I think the pull is actually does it in some cases when the call tapping is required and of course, one category is doing through mobile phone mobile phone as a weak encryption. So, if you are in the same cell where the transmission is happening you can listen to those slots in that is another way of doing it, but you need to know that how the call is from which number to which number at least one of them need to be known. So, this is the tapping mechanism which will be implemented. So, usually these kind of media gateways again need to be controlled and these are not done through SIP. SIP only initiates in sets of the sizing. So, for doing this media gateway control you need to do something more only SIP cannot do this. So, lot of other kind of command sets are required and we use a protocol called mega code for this. So, complete system is not SIP complete system is many more things actually I will just list most of them which are used. Then once we actually are doing a peer to peer communication between two end points the voice has to be transported it is a real time streaming. So, at time when you are playing certain things has to be fixed. So, time gap at which you have taken the samples and the recording side it has to be played back in a similar fashion on the receiver side. So, this requires a real time transport protocol this is again independent of SIP. SIP does not bother about it actually how the media is handled. So, you will require also RTP and I think I have there RFC numbers which are there. So, this is RFC 1889 3015. Now, RTP is for real time communication or control basically, but for the streaming media where packet loss is once a while it is loss is loss does not matter you do not require reliability you require real time streaming protocol this is usually for media audio and video not for the control signals RTP is for control signals. So, RTSP real time streaming protocol will also be part of the design this one requires an RFC of 2326. Now, when we will actually use SIP authorization authentication everything will be taken care of the two peers can talk, but what SIP actually does is provides a mechanism by which a object we call it OPEC object SIP never looks into what is there inside that. So, it is nothing but a file this file is simply transported to the right person he also sends back the file in the bag based on this this guys will share the information. So, they will share what is my IP address what is my port number at which you should connect. Honestly speaking this indexing server does not tell in SIP case once the SIP call is set up these guys through this route will inform that this is my IP address and port at which you should connect this guy will also tell this is my IP address and port at which you should connect. So, all the signaling will be routed through indexing server or SIP server we call it SIP proxy that is the term. So, that format of the file which will be transported through SIP is known as session description it is not technically it is not a protocol it only gives the format of the file through which a session can be described any generic session can be described is a format of the file is a text format it is not XML schema. Nowadays of course, everything we tend to use XML schemas because they are more generic, but this is a purely text based system which was built or evolved over the time actually and we call it SDP the term is session description protocol, but it is not a protocol as such and this one is 2327. So, system which we are going to actually have another two months in IITK will actually be based on SIP v2. We will have our own media gateway huge number 6000 analog lines will be terminating here. So, there is no exchange there is no switch on this side remember this I am talking about PSTN. So, there will be conventional switches in our design from here itself we will actually have 5000 wires going all the way to the each individual phone which is there. So, battery power will also be given by this equipment conventional telephony battery power is provided by exchange, but why telephony it is not provided by the exchange? It can be there is I triple this 802.13 I think that is what 12 one of those standard is there power over ethernet POE we call it. So, if you are most of the time what will happen is how you will connect your wife phone to the IP network most of the time it will be ethernet port which will be used you can actually use Wi-Fi nobody stops you can use Wi-Mex nobody stops you can have any other kind of physical layer or data link layer you can actually use on top of it. So, far it provides sufficient bandwidth in fact when negotiation of the codec will be done through this SDP thing which will be transported through SIP mechanism that time itself bandwidth constant will be taken care of. So, depending on available bandwidth different codecs might be chosen well a Skype also does the same thing. So, if the bandwidth is different Skype dynamically changes the codecs and that is why the quality of voice is almost it is not degrading much, but it degrades if the bandwidth goes down. Most of the time these are embedded devices. See, when you buy a mobile phone it contains I think most of them are built either with some processor. So, ARM has been kind of become a de facto standard, but of course now ATOM is also being used extensively for smartphones. So, in India we have got I think only one manufacturer providing a phone with ATOM most of the other smartphones are all with ARM series, but these are pretty much very powerful processors.  We will be actually buying again a smartphone kind of stuff we have already bought them, but it is a desktop versions it is a pretty much like a computer actually it comes from there is, but there is no keyboard keyboard is keyboard is like a telephone keyboard. The box will look like a telephone and basically it comes into that and they do not identify a connection. Yes, yes right, right it is exactly the same thing it will be connection to Ethernet port, but conventional phones also can be used by putting a small media gateway box. So, go to Cisco dot com dot com site the many manufacturers which are making this small box a small dub bar. It also has a small processor which is sufficient enough to do encoding, packetization, transmission, chip signaling your RTP there is no mega core required in this case this media gateway is not controlled by anybody. This is uncontrolled media gateway is only for one port. So, it is a different name given, but technically it is a media gateway, but does not require a mega core protocol. In fact, you can do away with mega core you would need not actually have it you can still do SIP based control, but then you require lot of power here which need to be done, but if you are connecting to a PSTN in our case SIP actually was fine, because we are not having actually any switch our condition was there is a media gateway and then there are 5000 phones analog phones connected on this side and then connecting over IP network and then we have actually twin redundant indexing servers we call it SIP proxies and then people are going to have their own wife phones they might actually put a conventional phone with a media gateway they can actually use a laptop or a machine a soft phone running on that all three possibilities will exist and depending on the capability of devices you can set up even video calls you can set up conference calls you can set up chat sessions actually email ideas technically can be used for doing all communication. So, when you want to make a phone call to an email ID. So, it will go to again the indexing server will find out for this email ID what is the corresponding number and then this will be controlling is in our case it is not controlling it is a SIP based system. So, it also is just visible as a 6000 wife phones connected through one single port, but if the PSTN switch would have been there if there would have been a exchanges network. So, you require a separate signaling between this. So, you require media gateway control in this case, because there is something more additional thing which are required that life is over right exchange will no more be there. We are just connecting existing 6000 5000 lines on to this media gateway the problem with this media gateway is again they are not coming in very large sizes they are mostly 24 port which are there. So, we have we will have lot of them stuck. So, 3000 will be here and 2000 will be there in hall 1 and they will be connected through IP network earlier we were actually having a separate fiber connecting to exchange. Over the time currently not because the people still have an issue if the power fails. See problem at a house if I put a wife phone I do not I will not be having ADSL. ADSL is being thrown out now. So, we have ethernet at every house and it is connected through optical fiber optical fiber cannot carry power we still do not have I think any mature technology by which I can also transfer power through optical fiber. I think we need to even have that kind of stuff. So, where actually we transmit signal as well as power through optical fiber optically and then we tap it out and use it for the switches on the other end. So, unless the fiber cut actually happens the power can still be transported currently the power is if transport is required you require either a separate power cable which has not been done in our case. So, it is a locally powered stuff, but with some kind of battery backup, but suppose a power fails in campus for more than 8 hours then there is a problem UPS will also age. So, some sites there will be disconnection because of that. So, those wife phones at houses will not work. So, you cannot even make a complaint to the IWT that my power is not coming. So, this is a very sensitive issue, this we have gone through ultimately we figured out we cannot we have to actually provide powering mechanism from the exchange side and that is why this media gateway has come into picture with conventional phones. So, every house in the campus will actually have two phones and technically it will have the same number and this will be an example of what I will talk about in SIP when a phone will come both the phones will ring and you can pick up any one of them and they are not parallel phones they are technically two separate phones and indexing server will now be sending message one to the gateway and one to the actual wife phone which are associated with the same number. See interesting thing is with the same IP address and port will have one possibilities for the same user ID I can register multiple devices. So, when number will come I this can be routed to all of them parallely can be probed any one of them is picked it is done this is known as forking in this case of SIP or one by one if you try this thing this does not respond within a time go to the next one go to the next one ultimately none of them are been picked up go to the voice mail box which is again maintained as a separate server and SIP will be routing the call to that is one possibility all of them can be done in parallely we will be actually using that now there is another interesting which can be done you are going to your friend's house you can go and actually type in a number and register even your phone number on that port now both the numbers are on the same port is like dual SIM system dual SIM phone. So, multiple identities can be there on single port that is possible ordinary phone ordinary analog phone which is already there as of now the big gateway we are already purchasing 6000 line that is already there that there are multiple of 24 ports actually they will be put in the rack there is issue of reliability and power see when I am putting everything in the exchange I have my good power backup source if I do it distributedly at 20 sites their hearts for example which have been built they have got a small ups now maintaining the number of the ups if they are more the more will be problem for you for maintenance I think the only problem with this system is this is not for the countries where power situation is bad that is the only thing which I feel is a problem I cannot transfer power I can I think over ADSL also it can be done, but usually ADSL ports are powered up locally all ADSL modems they are not powered through the telephone line, but if you can do that if you can actually make very low power ADSL modems which can take up power only from the telephone line itself then actually this is possible you should also now appreciate one more thing we call it loop unbundling I can change my operator I got a wire laid from telephone exchange of BSNL telephone exchange no more required you are going to for voice over IP only ADSL so that media is copper media is only used for data transport so voice is transported over ADSL over IP now so if at that exchange itself it is there I can actually now simply change my SIP provider my phone is still the same my port physical port is same IP address is same port number is same I can keep on changing my service provider at any point of time and I only pay to BSNL only for the loop and data transport charges and remaining charges I pay to the SIP service provider now here also issue of how you will do the billing will also come into picture currently what you do you get a telephone for every telephone you make the call make the payment 1 rupee per minute standard call rates now what you will do you are actually going to have a line you will pay for how many bytes which have been transferred and you will are you going to pay additionally to the SIP service provider that 1 rupee per minute his role is only when the call is set up once the call is set up you are directly talking peer to peer you no more require any more services so whether you talk for 1 hour whether you talk for 2 hours does not matter so it is how many times call will be set up per call set up the charges will be there by the SIP service provider and for the duration it means call will be free no it is not free if you talk for 2 hours you are transporting more bytes and you pay on per byte basis you are still paying to BSNL in that case but you can keep on changing your SIP service provider the way you want the way Vonage gateway people are actually using and it is a US number they are using SIP service provider of US it is I think fixed annual fee which is charged by in US actually by the companies but here you pay to BSNL for your data transport charge. ADSL is only a media link layer mechanism which provides a data transport it can when you are using Vonage it is going actually as voice over IP conventionally it is not because what happens from your phone you have an ADSL modem you have your machine or whatever your IP phone or Wi-Fi whatever it is this going over a single line you have it what we call a filter here there is a filter even before this modem actually there is a filter here so this is the way it goes actually so this is a in this direction it is band pass only lower band goes for this side it is a higher band which is not used by voice that will be used for data transport high pass filter this is a low pass filter on this side high pass on this side. So similarly there is a going to be a filtering so all high pass stuff will come low pass will go and this will be going for the exchange part where it is a line card so your voice can be routed through this conventional phones as far as this phone is concerned it does not see actually your digital part it does not see the ADSL thing it is just from this point onward to this point you are using common media but technically they are two separate networks physically they may be one because this line is maintained by the same guy and on top of it you are using voice over IP you are using your cable TV what is your IP TV we call it you are using your data connection all three so data voice and TV but I call it now actually multimedia so data voice TV everything will we actually first up and it is all kind of will mix into each other over time currently that is the way the BSN actually sells other stuff all three together triple play they call it now so triple play is for these three things. So you have to buy a separate set of box IP set of box here for connecting but I do not know whether it is the same ADSL modem plus set of box is common or it is separate I have never seen this set then logically it must be separate because it is an optional thing IP TV stuff so these four protocols will be actually used this simply will give a textual description of that for example I am sending a SDP message to you it will be sent through SIP mechanism and once I send a message I will say I want to actually have a phone call and I am going to use this part of the codec rate this is my capability because I am going to transport video I will they will not be any sorry they will be I am transporting audio no video I do not need a video call my bit rate maximum is this and I have these codecs available with me for example this message goes to you you will read this message and you have your own capabilities you will say yes I can make a audio call I have all that hardware with me you will confirm back and you will then find out what all audio codecs actually I have written what is my bit rate you know your capability whatever is common that common thing which what you are going to send it back to me. So common subset of the two will be sent back to me again in another SDP reply reverse also SDP comes and based on that I know we both are using the same rule. So this is the codec which I have to use I will trigger that codec you will also tell me I have to connect to your IP address is this your port number is this on which I have to connect for my media and once your thing come I will do acknowledgement and then you will set up a media stream and you will start talking and then we will disengage these guys the SIP service provider will not be aware of what I am doing actually but if he is routing the call in this fashion if there is intermediary gateway or then only he will know it media gateway also he might know it actually RTP is for signaling in real time for example I want to switch over RTP is again end to end it is nothing to do with SIP once I know my peers address I have a signaling thing I can start a RTP session so I can do a signaling on that so we will switch over the audio codec from higher to lower bandwidth depending on if my bandwidths are changing. So it is basically real time you will keep on telling me what is the performance of the reception whether something has to be dynamically changed streaming is I will be just maintaining what is called buffer control for example we do not use in our Braspati sync we are not using RTSP of course it is a bad design but that is the best which I could have done with whatever is existing manpower which I have in the project so we use buffer management if buffer over we actually crosses a certain flow we start dropping packets every third packet will be dropped if there again too much happen every alternate packet will be dropped or every tenth packet we start with ten actually every tenth packet will be dropped. So we keep the buffer within bounds if buffer actually empties out it means we are consuming at faster rate and buffer is incoming rate is lower so I have to now wait for some time so it is not that when the first packet comes I will start playing immediately I will wait I will wait for ten packets to accumulate and then I will start my player and audio and video need to be synchronized remember audio and video need to be synchronized time stamping is important there so when I am writing here something and I am speaking so all actions have to be synchronized so that is why what actually this streaming protocol actually does this is what is that feedback comes through RTP RTSP does not bother about feedback it does a synchronization part how many packets were dropped every packet will be numbered see the hundred packets were transmitted I got only these many these many media packets were dropped so you will try to make a guess based on that you remember you are doing UDP transport it is not TCP there is no retransmission even when you are doing signaling has to be done in real time can you do TCP you cannot you have to still do UDP UDP something is missed out crucial or not crucial that has to be seen well if we have actually for example are suffering from a situation we are actually currently in braspathism not using any one of these well this is not required there because it is a proprietary system these two could have been used this could have been used this we are not using we are using our own XML schema description proprietary this we are not using we are using buffer control here we do not bother if slight voice mismatch something happens you will always find the lip sync is a problem in braspathism Skype lip sync usually you would not actually figure it out they use the again their proprietary codec equivalent of which actually does provide synchronization of media streams synchronization I think is one of the major issues so it is always done through time stamping and creating separate buffers for each media stream and dropping and adding depending on the requirement real time I think what it means is another connotation of this is the clocks which I am going to use everybody's clock if you have actually done a GPS sync may be giving a GPS clock so everybody's clock will be uniform so today I have matched my clock with yours is 940 and tomorrow if I come at the same time your clock says 935 mine says 940 so 5 minute gap has been created this takes care of even that scenario when playback rate and recording rates are different they are bound to be different because all clocks are not synchronized over internet this sometimes what you call buffer overflow buffer underflow both problems can actually happen and but amazingly this is not perceived by us because when you play MP3 music for example on every computer the clock rate is different you buy 2 gigahertz but actually it is not 2 gigahertz 2 plus minus something which is there when you are playing the music you may not be actually listening to the original music is always slightly disturbed unless the clock rates are perfectly synced but humans should not be able to perceive only that much tolerance is there Zitter is going to be there you cannot remove that so far you can communicate it is fine okay now there is one more issue I would like to explain that and then come to the sip sometimes the problem of behind a proxy of behind a net that actually comes into picture in IIT Kanpur Skype does work actually without any issues even if you have behind a proxy so Skype if you go to tools options settings whatever it is and you will find there is a proxy setting there proxy username and password is also there okay so it is a STTP based transport what is STTP based transport STTP is a very unique kind of protocol it is I send a request you give me a response you forget about me after that so it does not remember what was my earlier request and what is my state so is a state less protocol there are no states maintained okay web servers of course do it actually maintain it through a different mechanism these are known as cookies session cookies basically through that which are sent with every request so it can figure out I am talking about which particular state information actually is transacted with every transaction so then it can remember that state on that basis using those pointers so it is a state less protocol so important thing that you want to send something to me how what happens in IITK suppose this is IITK network this is your machine this is a proxy this is the outside world I cannot send any information to you this is not a web server I am using private IP address so this guy cannot connect here so if I connect a Skype running here this Skype cannot send audio packets or video packets on to this side it is not possible it is always this is going to start the connection request the proxy for getting some information it will go to server and then information will come back this guy cannot initiate this stuff now that is a bottleneck here so far I have been using symmetric system both sides can independently push the information it will flow and to reach in this case they cannot reach it is not possible so what you will do is we have actually face this problem so we have used a technique here we used what we call time out mechanism when the periodic fetch so whenever you might have seen in your certain web pages when you download after some time it times out and it again refreshes the page there is a refresh interval so usually what happens whenever the STTP request is sent then the STTP response is sent in STTP response I actually can set a refresh interval so this guy is going to set the refresh interval and periodically keep on fetching now there again two methods in STTP one is get another one is post get method is you will send only the URL there is nothing is there in the payload part so you only can send everything in the URL itself and then only retrieve the information in response to the get and there is a post method in the post method I will have a URL I will also can add the payload part and there is a response to that post method I will get something in the payload so what actually usually Skype does or for that matter Braspati sync does client is periodically doing post method to a URL which responds to this and whatever packets which need to be transported on this direction will be sent as the payload of the post and when the response of that will be coming whatever were the packets which are queued up here will be sent in this now it does not if it is stopped sending post method that STTP request all queued up packets will remain queued up here they cannot be retrieved this is no way can send the packets only this has to push the packets and pull from there push the packets and pull from there this has to happen periodically at faster rate now that is the problem with STTP and STTP has its own overhead it has to set up a TCP connection all the way here fortunately for every request we do not now set up a TCP connection again and again usually you set up one single connection keep on sending a request on top of it and this will again set up a TCP connection all the way here and then STTP will be separate text based messaging on this TCP system so this is something which sometimes is required if you are behind a proxy and nothing else can be done even if you are behind a netting router then also it is not possible that this guy can send the information back here unless a static net entry gets created on this netting router so in IIT Kanpur it is not possible that somebody from outside can come in to and send information to ourselves we have to keep on pulling it out so your Skype which you are running in your machine is periodically pulling from some other Skype client which is running outside because your friend with whom you are talking might also be there behind a proxy this poor guy also can only push and periodically fetch these two guys when they need to communicate they require something outside without this this system cannot work it is encryption it is purely encryption I am going to come to how the authentication will be done in this case because I think Skype that is my guess I have not read the documents but the way it is operating I could actually figure out most likely this could be the one possible reason and I think the design should work so that is what I am also planning for our new Braspati 4 system as well as for Braspati sync clients ultimately we will actually move to that we will not be using no more login passwords login password will be used to get initial certificates only so Skype for example everybody starts doing login when the machine boots up is going to be a big problem on the server so I think they are using security certificates when you do first time login it takes some time once a certificates comes and gets installed everybody has authenticates by presentation of those certificates so you can authenticate with every your super peer with that you need not go to the central server so even if central server is down for some time services will not be off people we can still authenticate each other that is a good thing about that system it is actually server failure proof system even if server fails it is okay I will I will come to that now this is what is known as reflector reflector in we call it VR vs this is again a multimedia system which was built I think by lot of open source guys this we also cause call this same thing as a reflector in Braspati sync system this is known as super peer or super node in case of Skype and this actually means you are running a Skype you are connecting through your ADSL and you are using a public IP that technically means if you are not using HTTP proxy you are behind a netting router also it is fine because is usually the static net or sure in a public IP you run a Skype you are not making any call but still data is being transacted and remember your operator might be charging on per byte basis you are going to still pay without making any call so I think we close here and I will now come to the security architecture in the next class and then see after that


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