[Serusers] Proxy sending ACK on port 5060 instead of on contact port

Zeus Ng zeus.ng at isquare.com.au
Wed Sep 15 13:15:43 CEST 2004


Jan,

It true that the Request-URI is incorrect. However, I would not jump to
conclusion that it's Sjphone's problem yet unless it's a known problem with
their 1.0 version software. The capture is on the wan side of a ALG device.
>From my point of perspective, the ALG does not rewrite the address and port
correctly. That may be the problem.

Looking at fw2's dump, the 200OK (packet 16), the contact address is
sip:202.125.84.163:1585. A moment later, the same 200OK (packet 17) has
contact address of sip:202.125.84.1585. If both firewalls are the same, I
would say it's logic is wrong and causing Sjphone response with wrong
information. This is why I response in another mail that the contact address
is different on every other packet.

Mahesh,

Could you also send in the ethereal dump inside the ALG as well? That would
help isolate the problem, whether it's with Sjphone or the ALG.


Zeus

> -----Original Message-----
> From: Jan Janak [mailto:jan at iptel.org] 
> Sent: Wednesday, 15 September 2004 8:45 PM
> To: mahesh
> Cc: Zeus Ng; serusers at lists.iptel.org
> Subject: Re: [Serusers] Proxy sending ACK on port 5060 
> instead of on contact port
> 
> 
> The ACK from Sjphone is broken, it contains 
> sip:202.125.84.163 in the Request-URI but the Request-URI 
> should be sip:202.125.84.163:1585 (port is missing) because 
> that's what the UA receives in 200 OK.
> 
>   Jan.
> 
> On 15-09 15:22, mahesh wrote:
> > 
> > Hi Zeus,
> > 
> > I am attaching the ethereal captures of both fw1 and fw2(on wan
> > interfaces). Only relevant packets are shown in the capture 
> to minimize the 
> > file size.
> > The NAT IP used by fw1 is 202.125.84.164 and the one used by fw2 is 
> > 202.125.84.163
> > 
> > regards
> > Mahesh
> > 
> > 
> > >Mahesh,
> > >
> > >Given that you have ethereal capture, send it in to the 
> list and we 
> > >can see what's happening.
> > >
> > >Zeus
> > >
> > >> -----Original Message-----
> > >> From: serusers-bounces at lists.iptel.org 
> > >> [mailto:serusers-bounces at lists.iptel.org] On Behalf Of mahesh
> > >> Sent: Wednesday, 15 September 2004 5:15 PM
> > >> To: serusers at lists.iptel.org
> > >> Subject: [Serusers] Proxy sending ACK on port 5060 instead of on 
> > >> contact port
> > >>
> > >>
> > >> Hi all,
> > >>
> > >> I am using the following configuration to test SJPhone through 
> > >> IPTEL proxy server(publicly
> > >> available:195.37.77.99).
> > >>
> > >> HOST1(win2K)---FW1---Internet---FW2---HOST2(winXP)
> > >>
> > >> Host1 and Host2 are hosts with private IPs having SJPhone 
> > >> application. FW1 and FW2 are
> > >> firewall/NAT devices with SIP-ALG implementation. This means
> > >> all the SIP
> > >> messages are modified to include the public IPs in them. Also the
> > >> via,contact ports are modified. Now both host1 and host2
> > >> register with the iptel proxy server. A call is initiated
> > >> from host1. Host2
> > >> sends 200 OK response
> > >> to the HOST1. After this the ACK sent by Host1 is sent to
> > >> port 5060 on
> > >> HOst2,instead of the
> > >> contact port advertised in 200 OK. This is observed from
> > >> ethereal captures
> > >> on Host2. All these
> > >> messages are going through the proxy server(195.37.77.99).
> > >>
> > >> Can someone please tell me why the proxy server is behaving this 
> > >> way, i.e. sending ACK on 5060
> > >> instead of the contact. Is there anything that i am missing
> > >> here or doing
> > >> wrong.
> > >>
> > >> Thanks
> > >> Mahesh
> > >>
> > >> _______________________________________________
> > >> Serusers mailing list
> > >> serusers at lists.iptel.org 
> http://lists.iptel.org/mailman/listinfo/serusers
> > >>
> 
> 
> 
> > _______________________________________________
> > Serusers mailing list
> > serusers at lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers
> 




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