[SR-Users] Meaning of empty body in NOTIFY

[Eugen Dedu]

No idea?

On 05/06/11 22:31, Eugen Dedu wrote:
> Hi,
>
> ekiga.net registrar uses kamailio 1.5.3 (yes, a bit old...) and for
> users who are not registered an empty NOTIFY body is returned when asked
> by a SUBSCRIBE. What does this mean from SIP standard point of view, and
> from kamailio point of view (are they identical?) I see in RFC3265/3.1.6.2:
> .... If the resource
> has no meaningful state at the time that the SUBSCRIBE message is
> processed, this NOTIFY message MAY contain an empty or neutral body
> but is difficult for me to interpret what it means.
>
> Example: I ask the presence for a user xyz who registered and quit
> application long time ago:
>
> SUBSCRIBE sip:xyz at ekiga.net SIP/2.0
> CSeq: 1 SUBSCRIBE
> Via: SIP/2.0/UDP
> 82.238.108.175:5060;branch=z9hG4bKdabe824f-1a8e-e011-9efc-0024d693d8e8;rport
>
> User-Agent: Ekiga/3.3.1
> From: <sip:eugen.dedu at ekiga.net>;tag=4888824f-1a8e-e011-9efc-0024d693d8e8
> Call-ID: f602824f-1a8e-e011-9efc-0024d693d8e8 at snoopy
> Supported: eventlist
> To: <sip:xyz at ekiga.net>
> Accept: application/pidf+xml
> Accept: multipart/related
> Accept: application/rlmi+xml
> Contact: <sip:eugen.dedu at 82.238.108.175:5060>
> Allow:
> INVITE,ACK,OPTIONS,BYE,CANCEL,SUBSCRIBE,NOTIFY,REFER,MESSAGE,INFO,PING,PRACK
>
> Expires: 300
> Event: presence
> Content-Length: 0
> Max-Forwards: 70
>
> I receive the following answer:
>
> NOTIFY sip:eugen.dedu at 82.238.108.175:5060 SIP/2.0
> CSeq: 1 NOTIFY
> Via: SIP/2.0/UDP 86.64.162.35;branch=z9hG4bK2a99.b8a72c47.0
> User-Agent: Kamailio (1.5.3-notls (i386/linux))
> From: sip:xyz at ekiga.net;tag=f85b0bd16aaafa8479586ac9f88b3198-10a0
> Call-ID: f602824f-1a8e-e011-9efc-0024d693d8e8 at snoopy
> To: sip:eugen.dedu at ekiga.net;tag=4888824f-1a8e-e011-9efc-0024d693d8e8
> Contact: <sip:86.64.162.35:5060>
> Subscription-State: active;expires=370
> Event: presence
> Content-Length: 0
> Max-Forwards: 70
>
> To resume: What does SIP standard say about this NOTIFY with empty body?
> Does this mean that the user xyz is offline?
>
> Or does this mean that user's status has not changed? In fact, the
> NOTIFY with empty body (as shown above) is the first one sent by
> kamailio, so there is no "previous" state of that user, hence
> "unchanged" status has no meaning.
>
> Thank you,