The IMS foundation four safety the main specification.

One safety
Delivery the service of multimedia communication characteristically real time and person to person with the IP basis (like voice or videotelepony), likewise his matter with communication person to mechine (like the service gabling).

Two safety
Integrated the service of multimedia communication real time (like the video streaming and live chatting).

Three safety
Could serve and interact with the service and the application that were varied like combined presence and instant messaging.

Four safety
The Ease in melkukan the set up the multi-service in one sesion single or multi sesion simultaneously.

IMS could in toimplementasion wth GPR/EDGE, CDMA EV-DO, UMTS, xDSL or WLAN. To use IMS, the operator carried him out parallel from the available network.
When the operator wanted to place the service voice with communication IP, then IMS increased the application VoIP parallel.

As signaling protocol him, IMS used SIP (session initiation protocol) that was standardised by IETF (the internet engineering task force).
However, because initially standarisai this only was focussed to fixed the internet, the standard that was used by the network selullar will be different.
The theory SIP proxy server this that was worn 3GPP as the concept of the IMS foundation.

SIP that was used by IMS was as protocol application servers and softswitch that could interact with IAD or Access Gateway as well as developed communication between caller and that was called.

SIP could be used constructive caller, nerworking, as well as constructive the session of multimedia communication.
At this time was developed SIP especially to telepony that was mentioned SIP-T. the numbering System SIP-T fully pointed system cash that was used ITU-T, as well as to akomododir the mechanism interegrasi the service telepony with web like: UMS, the internet call waiting, click to dial and instant messanging