[Serusers] 483 - Too many hops

[Chintan Thakker]

Hi,
 Consider the following scenario. UA1 is trying to call UA2 both 
registered with the same proxy. (UA1 -> 'ser' -> UA2)

1.
 UA1 sends INVITE to the proxy with request uri set to UA2. It also sets 
the Route header in the invite to that of the proxy.
 This returns a 483 - too many hops to UA1

 It seems that in the above mentioned scenario, the proxy loops back the 
INVITE multiple times locally. This decrements the Max Forwards value 
every time until it becomes zero and hence sends 483 back to UA1. It 
seems to me this is not the correct behavior of the server. It should 
forward the request to UA2.

Thanks in advance,

Chintan

-- Start trace --

U 2003/06/20 15:24:42.362466 192.1.2.88:5060 -> 192.1.2.17:5060
  INVITE sip:9727610001 at 192.1.2.17 SIP/2.0.Via: SIP/2.0/UDP 
192.1.2.88:5060;b
  ranch=z9hG4bK421668676.Max-Forwards: 70.From: 9727619271 
<sip:9727619271 at 19
  2.1.2.88>;tag=421668676.To: 9727610001 
<sip:9727610001 at 192.1.2.17>.Call-ID:
   421668676 at 192.1.2.88.CSeq: 1 INVITE.Contact: 
<sip:9727619271 at 192.1.2.88>.C
  ontent-Type: application/sdp.Content-Length: 138.Route: 
<sip:192.1.2.17;lr>
  ..v=0.o=username 421668676 421668676 IN IP4 192.1.2.88.s=Session 
SDP.c=IN I
  P4 192.1.2.88.t=0 0.m=audio 54454 RTP/AVP 0.a=rtpmap:0 PCMU/8000.

U 2003/06/20 15:24:42.363813 192.1.2.17:5060 -> 192.1.2.88:5060
  SIP/2.0 100 trying -- your call is important to us..Via: SIP/2.0/UDP 
192.1.
  2.88:5060;branch=z9hG4bK421668676..From: 9727619271 
<sip:9727619271 at 192.1.2
  .88>;tag=421668676.To: 9727610001 <sip:9727610001 at 192.1.2.17>.Call-ID: 
4216
  68676 at 192.1.2.88.CSeq: 1 INVITE.Server: Sip EXpress router 
(0.8.11pre29 (i3
  86/linux))..Content-Length: 0..Warning: 392 192.1.2.17:5060 "Noisy 
feedback
   tells:  pid=15107 req_src_ip=192.1.2.88 req_src_port=5060 
in_uri=sip:97276
  10001 at 192.1.2.17 out_uri=sip:9727610001 at 192.1.2.17 via_cnt==1"....
#
U 2003/06/20 15:24:42.794681 192.1.2.17:5060 -> 192.1.2.88:5060
  SIP/2.0 483 Too Many Hops..Via: SIP/2.0/UDP 
192.1.2.88:5060;branch=z9hG4bK4
  21668676..From: 9727619271 
<sip:9727619271 at 192.1.2.88>;tag=421668676.To: 97
  27610001 
<sip:9727610001 at 192.1.2.17>;tag=b27e1a1d33761e85846fc98f5f3a7e58.4
  632.Call-ID: 421668676 at 192.1.2.88.CSeq: 1 INVITE.Server: Sip EXpress 
router
   (0.8.11pre29 (i386/linux))..Content-Length: 0..Warning: 392 
192.1.2.17:506
  0 "Noisy feedback tells:  pid=15107 req_src_ip=192.1.2.17 
req_src_port=5060
   in_uri=sip:9727610001 at 192.1.2.17 out_uri=sip:9727610001 at 192.1.2.17 
via_cnt
  ==71"....

-- End trace --

ps: We checked it with loose routing(suceeding ';lr' present in URIs in 
Route) as well as strict routing(suceeding ';lr' not present in URIs in 
Route). Should the type of routing used matter ?