This post particularly describes the gateways in IMS which communication back and forth with a legacy endpoints.To get a overview of IMS itself click here and to get a detailed description of IMS and its architecture click here .
What is IM-SSF ?
IP Multimedia Service Switching Function is a gateway to provide IN service such s legacy VPN ( Virtual Private Network ).
What is R-IM-SSF ?
Reverse IP Multimedia Service Switching Function Works on reverse principle to connect IN network to IMS services using IMS services such as FMFM ( find me follow me ) .
More link on telecom transformation , migration and inter-opereability :
How easier would it be if there was a infrastructure that could connect all devices all communication protocols , old legacy PSTN phones , vOIP ones like SIP all the PBXs of the worlds , GSM handsets even the very new WebRTC .
I have assembled my thoughts of a ideal communication platform in this blog-post , it involves GSM PLMN PBX IP with their respective gateways , meeting at a particular point which understand all protocols and provides a single registry service for telecom network operations like OSS , BSS ( I haven’t gone into too much of those details , since it spoils the fun ) .
Embedding a bit from NGN ( next generation network) , since I like the concept of softswitch ( Signalling gateway + Media Gateway controller ) .
All the above should connect to an IP network . why ? Because the future lies in IP telephony . Also because it becomes easier to make provisioning system for the admin to add new policies , review real-time statistics and for the users to avail new servers and customize their services settings any time .
Ofcourse there will arise codec inter- operability issue s, firewall ICE issues so on … yet all great inventions start with an idea , dont they 🙂