Conclusion: Approved.
S2-001400 from Alcatel: P-CSCF discovery (on 23.228, R00)
This contribution compares the different ways to perform proxy CSCF discovery:
1) SIP multicast: not suitable because several CSCF can answer at a time (see discussions from previous meeting)
2) New GPRS Protocol Configuration Option: not suitable because depending of the transport network (it works only with GPRS access)
3) Use of DHCP end to end: not suitable because involving lot of messages on the radio interface (even if it was the preferred solution identified at Vancouver meeting, but Laurent was not there).
4) Use of RFC 2782 – A DNS RR for specifying the location of services (DNS SRV): it has none of the previous drawbacks, so Alcatel propose to adopt it. The RFC is attached to the contribution.
Discussion: In the last bullet point before “3 Proposal”, read “P CSCF” instead of “S CSCF”.
How the UE get the DNS address: just like in R99, e.g. through PPP request (e.g. provided by the GGSN at PDP context activation)
How the UE get the domain name of the visited network: no domain name: the DNS is clever, and should be able to answer to a request without domain name.
The DNS might (optional) provide in one shot the P CSCF name and address but it might also be necessary to send 2 requests to the DNS: one to get the name, another to get the address.
Dostları ilə paylaş: | 
