[Serusers] PRACK
Greg Fausak
greg at august.net
Tue Mar 4 23:27:21 CET 2003
Jiri,
Yes, it was kinda quick.
I have been living and breathing SIP for the
last several weeks. Issues come and go in hours :-)
I'll recount what is up:
Ten days ago I sent an email to you, to which
you kindly responded, about the SNOM (apparent) inability to
process Record-routes correctly. Your response was
The record-route is there, SNOM needs to do what it says.
I forwarded your response to SNOM, and I
got a reply yesterday (something about all engineers
being at SIPIT).
Yesterday they responded with 'the SNOM phone receives
an OK from the PROXY server, and that OK does not include
the Record-route, therefore, the SNOM phone is compelled
to respond directly to the originating gateway'.
The actual exchange between the SNOM phone and the PROXY:
INVITE -> *
401 Unauthorized <- *
ACK -> *
INVITE (with credentials) -> *
100 Trying <- *
183 Ringing <-
PRACK -> *
200 OK <- * (this is OK for the PRACK)
200 OK <-
This is where things get off track, the SNOM phone wants to send the
ACK to the GATEWAY instead of the PROXY. All of the messages
above that have an * means no record-route is present in the message.
What SNOM is saying is that the *first* OK from the PRACK sets up
Who to send the message back to....that doesn't make sense to me. The
*second* OK from the INVITE is that SNOM is responding to, so why don't
they
use the record-route that is in that message.
The long winded answer is yes, they think SER should be providing a
'Record-route' in the first OK.
At least this is what I understand.
Does all of that make sense to you?
I can send an ethereal dump if you want it.
---greg
> -----Original Message-----
> From: Jiri Kuthan [mailto:jiri at iptel.org]
> Sent: Tuesday, March 04, 2003 11:42 AM
> To: Greg Fausak; serusers at lists.iptel.org
> Cc: sip at august.net
> Subject: Re: [Serusers] PRACK
>
>
> Greg,
>
> the email exchange was too fast for me -- is there any open issue now
> for which snom does not claim responsibility and the burden is on us?
>
> -Jiri
>
> At 03:47 AM 3/4/2003, Greg Fausak wrote:
> >I copied a few SNOM phone messages to the list.
> >I am having problems communicating with the
> >SNOM phone.
> >
> >I guess it isn't working because the SNOM phone
> >sends a PRACK after the 183, and the received
> >OK doesn't have a 'Record-Route'. This doesn't make
> >sense to me. I don't know why the phone is listening
> >to the first OK (the OK to the PRACK) rather than the
> >second OK (the OK to the INVITE).
> >
> >If that is the way it is then do I have the PROXY mis-configured?
> >
> >-----
> >
> > if(method=="INVITE" | method=="BYE" | method=="PRACK")
> > {
> > log(1,"TRACE: addRecordRoute()");
> > setflag(1);
> > setflag(2);
> > addRecordRoute();
> > };
> >
> > append_hf("P-hint: ATEND\r\n");
> > if(!t_relay())
> > {
> > sl_reply_error();
> > break;
> > };
> >
> >When I do a ngrep trace, I see the packet being relayed...
> >
> >----
> >#
> >U 2003/03/03 20:05:59.858473 216.87.145.22:5060 ->
> 216.87.144.203:5060
> >PRACK sip:2143357976 at 216.87.144.203;branch=0 SIP/2.0.
> >Via: SIP/2.0/UDP 216.87.145.22:5060;branch=z9hG4bK-bec8z5qwsbqg.
> >Max-Forwards: 70.
> >RAck: 5620 2 INVITE.
> >From: "snom man" <sip:4695461245 at augustvoice.net>;tag=1r1bpkl72i.
> >To: <sip:2143357976 at augustvoice.net;user=phone>;tag=63631E34-197C.
> >Call-ID: 3c26f8de39d9-7dyvkrekeha3 at 216.87.145.22.
> >CSeq: 4 PRACK.
> >Route: <sip:92143357976 at 216.87.144.196:5060;user=phone>.
> >Contact: <sip:4695461245 at 216.87.145.22:5060;line=1>.
> >Content-Length: 0.
> >Authorization: Digest
> >username="4695461245",realm="augustvoice.net",nonce="3e640b33
> 00000000dbb
> >edccd04f755cac7e3b6dd55d202c9",uri="sip:",response="3693b8283
> 95cd40fe1b1
> >ab5f9ad61308",algorithm=md5.
> >.
> >
> >#
> >U 2003/03/03 20:05:59.859540 216.87.144.203:5060 ->
> 216.87.144.196:5060
> >PRACK sip:92143357976 at 216.87.144.196:5060;user=phone SIP/2.0.
> >Record-Route: <sip:2143357976 at 216.87.144.203;branch=0>.
> >Via: SIP/2.0/UDP 216.87.144.203;branch=z9hG4bKe44a.ff0091c4.0.
> >Via: SIP/2.0/UDP 216.87.145.22:5060;branch=z9hG4bK-bec8z5qwsbqg.
> >Max-Forwards: 69.
> >RAck: 5620 2 INVITE.
> >From: "snom man" <sip:4695461245 at augustvoice.net>;tag=1r1bpkl72i.
> >To: <sip:2143357976 at augustvoice.net;user=phone>;tag=63631E34-197C.
> >Call-ID: 3c26f8de39d9-7dyvkrekeha3 at 216.87.145.22.
> >CSeq: 4 PRACK.
> >Contact: <sip:4695461245 at 216.87.145.22:5060;line=1>.
> >Content-Length: 0.
> >Authorization: Digest
> >username="4695461245",realm="augustvoice.net",nonce="3e640b33
> 00000000dbb
> >edccd04f755cac7e3b6dd55d202c9",uri="sip:",response="3693b8283
> 95cd40fe1b1
> >ab5f9ad61308",algorithm=md5.
> >P-hint: ATEND.
> >.
> >
> >#
> >U 2003/03/03 20:05:59.861477 216.87.144.196:5060 ->
> 216.87.144.203:5060
> >SIP/2.0 200 OK.
> >Via: SIP/2.0/UDP
> >216.87.144.203;branch=z9hG4bKe44a.ff0091c4.0,SIP/2.0/UDP
> >216.87.145.22:5060;branch=z9hG4bK-bec8z5qwsbqg.
> >From: "snom man" <sip:4695461245 at augustvoice.net>;tag=1r1bpkl72i.
> >To: <sip:2143357976 at augustvoice.net;user=phone>;tag=63631E34-197C.
> >Date: Tue, 04 Mar 2003 02:05:59 GMT.
> >Call-ID: 3c26f8de39d9-7dyvkrekeha3 at 216.87.145.22.
> >Server: Cisco-SIPGateway/IOS-12.x.
> >CSeq: 4 PRACK.
> >Content-Length: 0.
> >.
> >
> >#
> >U 2003/03/03 20:05:59.861705 216.87.144.203:5060 ->
> 216.87.145.22:5060
> >SIP/2.0 200 OK.
> >Via:SIP/2.0/UDP 216.87.145.22:5060;branch=z9hG4bK-bec8z5qwsbqg.
> >From: "snom man" <sip:4695461245 at augustvoice.net>;tag=1r1bpkl72i.
> >To: <sip:2143357976 at augustvoice.net;user=phone>;tag=63631E34-197C.
> >Date: Tue, 04 Mar 2003 02:05:59 GMT.
> >Call-ID: 3c26f8de39d9-7dyvkrekeha3 at 216.87.145.22.
> >Server: Cisco-SIPGateway/IOS-12.x.
> >CSeq: 4 PRACK.
> >Content-Length: 0.
> >.
> >
> >-----
> >There is a Record-route going out, but not one coming back.
> >Does a Record-route need to be injected into the last
> >OK back to the UA?
> >
> >This is too hard :-)
> >
> >---greg
> >
> >
> >
> >_______________________________________________
> >Serusers mailing list
> >serusers at lists.iptel.org
> >http://lists.iptel.org/mailman/listinfo/serusers
>
> --
> Jiri Kuthan http://iptel.org/~jiri/
>
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