The Diameter base protocol is used to provide reliable and secure communication for Diameter applications between and across the Diameter peers (diameter clients, agents, or servers). Its routing capabilities to transport traffic across Diameter nodes rely on Diameter identities that are composed of host and realm names. Diameter applications supported in SR OS are NASREQ, Gx, and Gy.
In the SR OS, Diameter base protocols run over TCP. It starts by establishing a TCP connection with peers, followed by capability exchanges. A data exchange occurs in the form of Attribute Value Pairs (AVPs). Some of these AVPs are used by the base protocol itself, while others are used by Diameter applications that are layered on top of it.