 The RoCE protocol allows lower latencies than its predecessor, the iWARP protocol.There exist RoCE HCAs (Host Channel Adapter) with a latency as low as 1.3 microseconds while the lowest known iWARP HCA latency in 2011 was 3 microseconds.The RoCE v1 protocol is an Ethernet link layer protocol with Ethertype 0x8915.