Any comments on this?
-Maxim
On Tue, Apr 08, 2003 at 07:41:55PM +0300, Maxim Sobolev wrote:
Yet another obstacle on the way of proper INVITE-ACK matching for negative replies: some UA might pick up Via parameters from provisional responses and then copy them into ACK. For example ATA-186 does this with received/rport parameters, so that they don't match with ones from INVITE:
(gdb) print t_msg->via1->name $18 = { s = 0x282ed926 "SIP/2.0/UDP 192.168.1.20:5060\r\nFrom: sip:380442466396@64.180.102.72;user=phone ;tag=3473403119\r\nTo: sip:122@64.180.102.72;user=phone\r\nCall-ID: 3487919719@192.168.1.20\r\nCSe q: 2 INVITE\r\nContact: <sip"..., len = 3} (gdb) print p_msg->orig $19 = 0x80d51f8 "ACK sip:122@64.180.102.72;user=phone SIP/2.0\r\nVia: SIP/2.0/UDP 192.168.1.20:5060; rport=5060;received=193.111.9.226\r\nFrom: sip:380442466396@64.180.102.72;user=phone;tag=347340311 9\r\nTo: <sip:122@64.18"...
As you can see, in the INVITE we had 1st Via:
SIP/2.0/UDP 192.168.1.20:5060
While in the ACK:
SIP/2.0/UDP 192.168.1.20:5060;rport=5060;received=193.111.9.226
Needs to be corrected as well.
-Maxim
On Tue, Apr 08, 2003 at 07:26:54PM +0300, Maxim Sobolev wrote:
Not only that, but there is also a bug which causes match failure due to extra space in the ACK, see the gdb session below:
0x2a17b904 in t_lookup_request (p_msg=0x80d4c88, leave_new_locked=1) at t_lookup.c:268 268 {int b=1; while (b);} (gdb) s b=0 (gdb) n 270 if (!EQ_LEN(callid)) continue; (gdb) print t_msg->callid->body $8 = { s = 0x282ed9b8 "3650497277@192.168.1.20\r\nCSeq: 2 INVITE\r\nContact: sip:380442466396@192.168.1. 20:5060;user=phone;transport=udp\r\nUser-Agent: Cisco ATA 186 v2.15 ata18x (030401b)\r\nAuthorizat ion: Digest username="3804"..., len = 23} (gdb) print p_msg->callid->body $9 = {s = 0x80bdf73 " 3650497277@192.168.1.20\r", len = 24}
As you can see, the callid is the same, but EQ_LEN(callid) will be false, due to the fact that p_msg->callid->body.len != t_msg->callid->body.len.
-Maxim
On Tue, Apr 08, 2003 at 05:56:17PM +0300, Maxim Sobolev wrote:
Sorry, further investigation shown that this particular problem was caused by the typo in our fix for hashing function (one found in 0.8.10 didn't bother to strip insignificant chars from call-id and cseq number). I've fixed that and the problem gone.
However, we have another problem with ACK matching. The problem is that we are using propiertary module which queries billing engine via Radius and uses its replies to rewrite URI. Since it isn't practical to run that query on each request received, we are only performing it on INVITEs, which is fine as long as the next hop is always B2BUA that only cares about method URI in INVITE requests and ignores it in any subsequent requests. The typical sequence looks like the following:
- ATA->SER:
INVITE xyz@foo.bar
- SER->BILLING
please expand xyz
- BILLING->SER
xyz expands to 123456
- SER->B2BUA (t_relay_to())
INVITE 123456@foo.bar
Everything is fine when INVITE transaction ends with a 200 OK, in this case ATA generates ACK to acknowelege 200 OK using information from that 200 OK, i.e. `ACK 123456@foo.bar', not `ACK xyz@foo.bar'. The problem happens if transaction ends with 4xx error, or is cancelled by the originating party, in this case ATA acknoweleges receipt of final negative response with `ACK xyz@foo.bar' so that tm module is unable to match ACK to original INVITE.
Do you have any ideas how to properly solve this problem without introducing steps (2) and (3) above for every ACK request as well? It would be inacceptable for us since each BILLING query means extra database access, therefore is puting extra load on the system and degrading its performance (normal call involves 2 ACKs, so that there would be 3 db accesses instead of 1).
I think that it should be possible to resolve the problem by modifying tm module to match ACKs for non-200 replies to original uri in INVITE instead to rewriten one. What do you think? Is there any potential problems with this approach?
-Maxim
On Mon, Apr 07, 2003 at 10:41:31PM +0200, Jiri Kuthan wrote:
Maxim,
neither did I find a reason why the ACK is not matched. I might be wrong but my guess is that it is a config issue -- are you sure it enters t_relay in your script?
-Jiri
At 09:19 PM 4/7/2003, Maxim Sobolev wrote:
Folks,
I found that in the stateful mode, SER is having troubles matching ACKs to negative replies when Vovida B2BUA (1.5.0) is used as one UA, while Cisco ATA 186 as another one. Following is a dump of the session illustrating the problem. As you can see, SER keeps retransmiting 480, despite receiving properly formed ACKs. Does anybody have any ideas what the problem might be?
-Maxim P.S. I am also seeing in the logs the following warnings:
Apr 7 12:05:28 demo ser[86090]: WARNING: sip_msg_cloner: header body ignored: 4096
B2BUA->SER
INVITE sip:16045215277@demo.portaone.com:5060;transport=udp;user=phone SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 cisco-GUID: 200546447-2237180178-1764455078-2518034476 CSeq: 2 INVITE Max-Forwards: 10 Expires: 300 Contact: sip:380442466396@64.180.102.72:5061;user=phone User-Agent: PortaSIP (030401b) Content-Type: application/sdp Content-Length: 309 o=380442466396 20916528 20916528 IN IP4 192.168.1.20 s=ATA186 Call c=IN IP4 193.111.9.226 t=0 0 m=audio 14000 RTP/AVP 4 8 0 101 a=rtpmap:4 G723/8000/1 a=rtpmap:8 PCMA/8000/1 a=rtpmap:0 PCMU/8000/1 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 a=direction:active a=oldmediaip:192.168.1.20
SER->B2BUA
SIP/2.0 100 trying -- your call is important to us Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Sip EXpress router (0.8.10 (i386/freebsd)) Content-Length: 0
SER->ATA
INVITE sip:16045215277@172.17.1.127:5060;user=phone;transport=udp SIP/2.0 Record-Route: sip:16045215277@64.180.102.72;branch=0 Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bK56f9.3c3c97acad0bdb329284be13e26ccc54.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 cisco-GUID: 200546447-2237180178-1764455078-2518034476 CSeq: 2 INVITE Max-Forwards: 9 Expires: 300 Contact: sip:380442466396@64.180.102.72:5061;user=phone User-Agent: PortaSIP (030401b) Content-Type: application/sdp Content-Length: 309 o=380442466396 20916528 20916528 IN IP4 192.168.1.20 s=ATA186 Call c=IN IP4 193.111.9.226 t=0 0 m=audio 14000 RTP/AVP 4 8 0 101 a=rtpmap:4 G723/8000/1 a=rtpmap:8 PCMA/8000/1 a=rtpmap:0 PCMU/8000/1 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 a=direction:active a=oldmediaip:192.168.1.20
ATA->SER
SIP/2.0 100 Trying Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bK56f9.3c3c97acad0bdb329284be13e26ccc54.0 Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 0
ATA->SER
SIP/2.0 183 Session Progress Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bK56f9.3c3c97acad0bdb329284be13e26ccc54.0 Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 201 Content-Type: application/sdp o=16045215277 1110 1110 IN IP4 172.17.1.127 s=ATA186 Call c=IN IP4 64.180.102.72 t=0 0 m=audio 10000 RTP/AVP 4 101 a=rtpmap:4 G723/8000/1 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15
SER->B2BUA
SIP/2.0 183 Session Progress Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 221 Content-Type: application/sdp o=16045215277 1110 1110 IN IP4 172.17.1.127 s=ATA186 Call c=IN IP4 64.180.102.72 t=0 0 m=audio 10000 RTP/AVP 4 101 a=rtpmap:4 G723/8000/1 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 a=direction:active
ATA->SER
SIP/2.0 480 Temporarily Not Available Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bK56f9.3c3c97acad0bdb329284be13e26ccc54.0 Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 0
SER->B2BUA
SIP/2.0 480 Temporarily Not Available Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 0
B2BUA->SER
ACK sip:16045215277@demo.portaone.com:5060;transport=udp;user=phone SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone;tag=2698540533 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 ACK Max-Forwards: 70 Content-Length: 0
SER->ATA
ACK sip:16045215277@172.17.1.127:5060;user=phone;transport=udp SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bKbc52.5db2fe1211adfdd0d5db3db6e2295344.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone;tag=2698540533 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 ACK Max-Forwards: 69 Content-Length: 0
SER->B2BUA
SIP/2.0 480 Temporarily Not Available Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 0
B2BUA->SER
ACK sip:16045215277@demo.portaone.com:5060;transport=udp;user=phone SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone;tag=2698540533 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 ACK Max-Forwards: 70 Content-Length: 0
SER->ATA
ACK sip:16045215277@172.17.1.127:5060;user=phone;transport=udp SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bKbc52.5db2fe1211adfdd0d5db3db6e2295344.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone;tag=2698540533 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 ACK Max-Forwards: 69 Content-Length: 0
SER->B2BUA
SIP/2.0 480 Temporarily Not Available Via: SIP/2.0/UDP 64.180.102.72:5061 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 To: sip:121@64.180.102.72;user=phone;tag=2698540533 Call-ID: 3135130751@192.168.1.20 CSeq: 2 INVITE Server: Cisco ATA 186 v2.15 ata18x (030401b) Content-Length: 0
B2BUA->SER
ACK sip:16045215277@demo.portaone.com:5060;transport=udp;user=phone SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone;tag=2698540533 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 ACK Max-Forwards: 70 Content-Length: 0
SER->ATA
ACK sip:16045215277@172.17.1.127:5060;user=phone;transport=udp SIP/2.0 Via: SIP/2.0/UDP 64.180.102.72;branch=z9hG4bKbc52.5db2fe1211adfdd0d5db3db6e2295344.0 Via: SIP/2.0/UDP 64.180.102.72:5061 To: sip:121@64.180.102.72;user=phone;tag=2698540533 From: sip:380442466396@64.180.102.72:5061;user=phone;tag=4505a91c4165b3ffb1b4df0ff79c2904 Call-ID: 3135130751@192.168.1.20 CSeq: 2 ACK Max-Forwards: 69 Content-Length: 0
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