R.2A Usage of SDP

24.2293GPPIP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Release 18Stage 3TS

R.2A.0 General

Not applicable.

R.2A.1 Impact on SDP offer / answer of activation or modification of IP-CAN for media by the network

If the UE is attached to the EPC via S2b using untrusted WLAN IP access, and IKEv2 multiple bearer PDN connectivity is used in the PDN connection according to 3GPP TS 24.302 [8U], then:

1) if an additional IPSec ESP tunnel is established according to 3GPP TS 24.302 [8U] and the related SDP media description needs to be changed, the UE shall update the related SDP information by sending a new SDP offer within a SIP request, which is sent over the existing SIP dialog; and

2) if an IPSec ESP tunnel is modified according to 3GPP TS 24.302 [8U] and the related SDP media description need to be changed, the UE shall update the related SDP information by sending a new SDP offer within a SIP request, that is sent over the existing SIP dialog.

NOTE: The UE can decide to indicate additional media streams as well as additional or different codecs in the SDP offer than those used in the already ongoing session.

R.2A.2 Handling of SDP at the terminating UE when originating UE has resources available and IP-CAN performs network-initiated resource reservation for terminating UE

Not applicable.

R.2A.3 Emergency service

No additional procedures defined.