The 5060 IP Call Server (ICS) Cheat Sheet by Steve Fowlkes

The 5060 is on one box, but is made up of many functions that offer a huge portion of the IMS control functi­ona­lity. It houses the entire SIP chain of signalling commun­ication for an IMS network as well as a few other functions. These include:

The 5450 IP Session Controller
The 5420 Converged Telephony Server
The 5060 Media Gateway Controller 8
Includes the Media Gateway Control Function (MGCF)
Includes the Media Resource Function (MRF)
The Internal Home Subscriber Server (iHSS)
The Internal Charging Collection Funcion (iCCF)
The Internal Access Gateway Control Function (iAGCF)

Each of these functions are further broken down into sub-fu­nctions that provide IMS functi­ona­lity.

The Internal HSS, a variant of the external HSS, provides a database of home subscriber inform­ation including:

Subscriber Identity (Public and Private ID's)
Service Profile
Location of the Subscriber

This inform­ation is provis­ioned by using the 1360 COM.

The IP Session Control Function is the on board suite that let's the ICS control the signaling SIP flow for call setup. It includes:
The Proxy CSCF
The Interr­ogating CSCF
The Serving CSCF
The Emergency CSCF
The Break-out Gateway Control Function This is what handles calls that must exit the IMS core, due to any manner of errors.
The Servic­e-based Policy Decision Function
The IMS Gateway Function This performs inter-­working between the Servin­g-CSCF and an Offline Charging System.

Each of these functions interacts with other higher (Appli­cation Layer) or lower (Media Layer) functions and servers.

The iAGF is techni­cally apart of the IP Session Controller Functi­ona­lity. It is used to talk with the 7510 Media Gateway's Centra­lized Access Gateway to provide media transl­ation of POTS / PSTN phones.

The iAGF will appear as a Proxy-­CSCF, in getting to the IMS core. It 'speaks' H.248 to the 7510's C-AGW, and SIP to the other IMS CSCF's.

The 5420 CTS is an Applic­ation Server that is on board that 5060 IP Call Server.
It works in the "­App­lic­ation Layer". It provides voice services such as:
Number Transl­ation
Number Normal­ization
Caller-ID Features
Call Return­/Bl­ocking
Ring-back Tones
Anonymous Call Blocking
Black Listing
Call Parking
Author­ization Codes
Call Confer­ences
Call Trace
Web Portal GUI Management
Integrated Charging Function
Many, Many More...

The Media Gateway Contro­ller, as the name implies, controls the 7510 MGW, using H.248 signaling. It's other functions include much to do with SS7 signaling, including:

SS7 Termin­ation
Border Control for other carrier's SIP networks
Service Based Policy Decision for other carrier's IP networks. It will control the 7510 MGW's Interc­onnect Border Gateway Function (IBGF)to do this