12 Nov
2004
12 Nov
'04
1:26 p.m.
Friday, November 12, 2004, 10:02:06 AM, Andrei wrote:
APO> On Nov 11, 2004 at 00:04, Thomas <thomasj(a)eworld.hu> wrote:
>
> Hello!
>
> I'm trying to make my 1st SIP-based system working. I use SER-0.8.14
> on Linux Sarge. I have usually UAs behind NAT firewalls.
>
> I found a case, when UAs are working very oddly, I can't call from one
> of them, after sime time I can't reach one of them from outside, after
> some time when I call one UA, the 2nd is answering (and the same time
> when I call 2nd UA, the 2nd is answering).
>
> I have 2 UAs [Grandstream BT100 & X-Lite v2.0] behind a linux NAT
> firewall. Both UAs use the same STUN and SER server.
> I did some tcpdumps and I found an interesting thing:
>
> Internet Protocol, Src Addr: <FWPUBLICIP> (<FWPUBLICIP>), Dst Addr:
<SERIP> (<SERIP>)
> User Datagram Protocol, Src Port: 1024 (1024), Dst Port: 5060 (5060)
> Session Initiation Protocol
> Request-Line: REGISTER sip:<MYDOMAIN> SIP/2.0
> Method: REGISTER
> Resent Packet: True
> Suspected resend of frame: 31
> Message Header
> Via: SIP/2.0/UDP
> <FWPUBLICIP>;branch=z9hG4bK0dbeeb499dbd416e
APO> [...]
> What is interesting is that REGISTER message went
out from port 1024
> but 200 OK came to port 5060. Is this OK? I think here is some problem
> and this can make the phones working oddly.
APO> If the phone wanted the answer on 1024, it should have advertised it in
APO> the REGISTER's via. A least it should have added a rport parameter to
APO> the Via.
APO> You can try using force_rport() in ser config for all requests (or for
APO> requests comming from this phone). This might break asymmetric UAs
APO> though (not very common these days).
APO> Andrei
Hello!
Thank you for your fast answer.
force_rport() is already present in config (for REGISTER). Where
should I put it? (maybe I have in wrong place)
How could I trace the problem? What would help me/you to say where is
the problem? Maybe the NAT firewall messes up those ports? (that is a
classical NAT firewall based on linux and netfilter, nothing special)
Unfortunately I don't have much experience with SIP (just 1 week),
however I'm reading manuals, but it looks, too hard problem at the
beginning for me. But I will keep trying ;)
Thanks in advance!
Kind regards,
Tamas J.