VoIP phone service

A VoIP telephone service lets you make and take calls via a dedicated IP phone, your existing phone via an adapter, or software on your computer.

VoIP stands for Voice over Internet Protocol. It’s basically a set of technologies that enables users to make and receive phone calls over an internet connection, instead of using the traditional Public Switched Telephone Network (PSTN).

How to us VoIP

To place or receive a VoIP call, all you need is a stable internet connection and suitable software or hardware to access your VoIP system.

The technology uses “protocols” to convert voice signals (phone calls) or multimedia (documents or SMS text) into “packets” of data.

These packets are transmitted over broadband or Wi-Fi connections within a Wide-Area Network (WAN) or Local Area Network (LAN). The phone at the receiving end then decompresses the data and plays it back for the recipient to hear or see.

The protocols are responsible for establishing the connection and making sure the packets reach their destination. A set of control protocols, each with different functions, works together in real time to replicate the functions of traditional telephony. The main protocols are:

Session Initiation Protocol

Real-time Transport Protocol

Transmission Control Protocol

User Datagram Protocol (UDP)

What are the benefits of VoIP phone systems?

There are so many benefits that it’s hard to know where to begin! Here are just a few of the best:

  • Cost
  • Convenience
  • Flexibility
  • Scalability
  • Functionality

How does ISDN work?

ISDN works by using copper wires to connect to many different channels via dial-up service. The channels can be put into either one of two categories:

  1. B (bearer) channel - this is a channel that transmits voice data, as well as information about the users
  2. D (delta) channels - this is a channel that transmits other types of data, including signaling and packet networking

Together, these two types of channels help manage the information traffic as the “internal” phone system connects to the external plain old telephone service (POTS).

What are the types of ISDNs?

There are two types of ISDN lines:

  • PRI: Primary Rate Interface
  • BRI: Basic Rate Interface

Primary Rate Interface (PRI)

This is the faster of the two variants, but it’s also more expensive. A technology that’s been around since the 1980s, it’s a circuit technology that lets organizations use a single line for up to 23 different transmissions at the same time.

In the PRI setup, you get multiple B channels and D channels which are collectively supported by speeds of up to 2.94 Mbps.

Basic Rate Interface (BRI)

Of the two variants, this is far more affordable. But it’s not called “basic” for nothing—while you can most certainly use it for more than one transmission at a time, it can’t adequately address the needs of larger operations.

The BRI setup also lets you make use of B and D channels. The difference is that this interface is limited to two B channels and one D channel, with a maximum speed of 128 Kbps.

How to set up ISDN

Setting up an ISDN connection involves using a serial port and plugging in the telephone company line.

The process of setting up ISDN involves:

  • Loading the modem driver disk and programming the modem
  • Pointing the modem toward the right phone numbers
  • Setting your connection speeds for each line
  • Directing your modem to dial your ISP (Internet Service Provider) — this phone number should be provided by your ISP
  • If necessary, set your modem for BONDING (the ability to access higher speeds by allowing your modem to dial both phone numbers at once)

Is ISDN still in use today?

Short answer? Sort of.

Long answer -

ISDN is falling out of favor

ISDN may very well still be available in some parts of the world, where getting a broadband connection isn’t really possible just yet. But beyond that, there are few reasons for new businesses, or even established ones, to choose ISDN lines and hardware that’s compatible with it. In fact, it’s barely even ideal for use in the average modern household anymore.

The need for speed

Today, we have much faster connections. ISDN’s speeds of 128kbps to 2.94Mbps may have been blisteringly fast compared to the 56kbps available to home users in the 1990s; but these days, they’re hardly a match for always-on cable and fiber broadband.

The fight for flexibility

In addition, this technology doesn’t give organizations much room for flexibility in terms of expansion, relocation, and the like. This is because ISDN wasn’t able to evolve with the needs of 21st-century businesses, which have come to value agility, mobility, and geographically distributed workforces. Instead, it’s stuck to a model that forces employees to stay put in one location if they want to use the company network.

It’s not worth the investment anymore

Between its inability to catch up with the speed of broadband and its failure to grow with the businesses it used to serve so well, the idea of spending money on the specialized (and pricey!) ISDN technology is becoming harder to justify.

This is why it isn’t really a surprise that ISDN is being phased out in many areas of the globe. British Telecom, for example, announced that they would stop selling new ISDN lines in 2020, with the goal of switching the service off entirely in 2025. In other words, this is now largely recognized as an obsolete technology.

It won’t be long before the world as a whole will stop relying on ISDN completely.

Are there reasons for people to still use ISDN?


Some of the reasons people still choose to use ISDN are:

  • It offers multiple digital services that operate through the same copper wire
  • Digital signals broadcast through telephone lines.
  • ISDN provides a higher data transfer rate.
  • Can connect devices and allow them to operate over a single line. This includes credit card readers, fax machines, and other manifold devices.
  • It is up and running faster than other modems.

Of course, the above are only true if there is limited or no access to DSL and WAN (wide area network) internet.

What does the world after ISDN look like?

Telephony providers are increasingly moving over to using IP calling for all of their connections. Modern PBX systems are designed with this in mind and are generally not expected to work with older lines.

In fact, a growing number of organizations have begun to transition all their communications to the cloud since many solutions of that type make it easier to create customizable virtual work environments.

VoIP for unified communications

One of the major advantages of implementing a VoIP system is that it plays well with a unified communications infrastructure. Using protocols related to IP telephony, your voice calls can operate on the same platform as other modes of communication like video conferencing and team messaging.