Hi all,

I saw in one of the examples below that the UA includes two P-preferred-id 
headers. I know that's Ok according to RFC3325:

"A P-Preferred-Identity header field value MUST consist of exactly one
name-addr or addr-spec. There may be one or two P-Preferred-Identity
values. If there is one value, it MUST be a sip, sips, or tel URI.
If there are two values, one value MUST be a sip or sips URI and the
other MUST be a tel URI. It is worth noting that proxies can (and
will) remove this header field."

I wonder what is the expected behaviour of the Proxy. I see two options:

1)if both are valid, the Proxy (P-CSCF in IMS) will choose one ramdonly.

2) the Proxy adds two P-Asserted-id headers, as per the two valid 
P-preferred-id headers. Two P-asserted-id headers are also allowed according to 
RFC3325

"A P-Asserted-Identity header field value MUST consist of exactly one
name-addr or addr-spec. There may be one or two P-Asserted-Identity
values. If there is one value, it MUST be a sip, sips, or tel URI.
If there are two values, one value MUST be a sip or sips URI and the
other MUST be a tel URI. It is worth noting that proxies can (and
will) add and remove this header field."

I didn't find in RFC3325 any sentence explaning the expected behaviour of the 
Proxy when two valid P-preferred-id headers are present. Shouldn't that case be 
considered in the RFC?

Miguel


----------------------------------------
Jose Miguel Torres 
CND division - IMS System Engineering - Motorola
Tel: +34914002226, Mobile: +34629545668



INVITE sip:2300 at Asterix SIP/2.0
Via: SIP/2.0/UDP 192.168.1.126:5060;branch=z9hG4bK-276428-27856
From: "4302" <sip:4302 at Asterix>;tag=27642829233
To: <sip:2300 at Asterix>
Call-ID: 27642811596 at 192.168.1.126
CSeq: 20 INVITE
Contact: <sip:4302 at 192.168.1.126:5060>
Max-Forwards: 70
User-Agent: My UA
Privacy: none
P-Preferred-Identity: "4302" <sip:4302 at Asterix>
P-Preferred-Identity: <tel:4302>
Allow: INVITE, ACK, CANCEL, BYE, OPTIONS
Content-Type: application/sdp
Accept: application/sdp
Content-Length:   234

v=0
o=iS3000 0 0 IN IP4 192.168.1.216
s=-
c=IN IP4 192.168.1.216
t=0 0
m=audio 49368 RTP/AVP 0 8 18 96
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=rtpmap:96 telephone-event/8000
a=ptime:40
a=sendrecv


_______________________________________________
Sip-implementors mailing list
[email protected] 
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
_______________________________________________
Sip-implementors mailing list
[email protected]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to