How does IMS protocol works?Is this same as VOIP ?

Question

In TS 23.221 7.2a, there is a note describe that "Whether to perform combined EPS/IMSI attach/combined TA/LA Update or EPS attach/TAU for the case of "IMS PS Voice preferred" is to be evaluated in each release of the specifications.", but I can not find any information about that.

Answer 1

Hi Bharath,

IMS is an application layer protocol and it uses RTP protocol as an transport protocol. It is kind of VIOP only difference here is it uses iMS protocol and IMS PDN. IMS also transfer the DATA via IP.