Re: nf_conntrack_sip and nf_nat_sip can do this??

[Patrick McHardy <kaber@trash.net>]

rebeca.martinez-garcia@estudiant.upc.edu wrote:
> I have been investigating and the registration process is done correctly:
> a private user inside the LAN sends the REGISTER to the Proxy via the
> gateway and it changes the private IP for the public IP. When the Proxy
> answers it, the gateway does the same but in the other way round.
> 
> It is during the INVITE that I have seen some problems.
> 
> When a private client sends an INVITE directed to a client outside the
> LAN (a public client) again it works ok. However, when a public client
> sends an INVITE to call a private client there is an error:
> 
> Public Client to my Proxy:
> INVITE sip:private_client@domain_name
>        From:caller@domain_name
>        To:callee@domain_name
>        contact: caller@10.1.x.x
> 
> The proxy talks with my server to know the location of the callee and it
> answers with the public IP of my gateway in a determined port. So the
> Proxy sends the invite to it:
> INVITE sip:private_client@10.1.x.y
>        From:caller@domain_name
>        To:callee@domain_name
>        contact: caller@10.1.x.x
> 
> And now the gateway redirects the invite to my private client but it
> DOES NOT change the R-URI. However, when the invite reaches the client,
> it answers with a "183 Session progress" and then it puts its correct
> contact:
> 183 SESSION PROGRESS
>        From:caller@domain_name
>        To:callee@domain_name
>        contact: callee@192.168.x.x
> 
> And now, in the following messages between the caller and the callee, it
> changes correctly the private address for the public one and in the
> other way round.
> It is as the gateway only starts to work correctly if the message comes
> from the LAN.

Please send me a binary tcpdump (-w file -s0) containing the
traffic of both the incoming and outgoing interface of the
NAT GW.

> I have checked the /proc/net/nf_conntrack_expect and it contains this:
> 
> 598000 l3proto = 2 proto=17 src=0.0.0.0 dst=10.1.x.x sport=0 dport=1061
> PERMANENT
> 597394 l3proto = 2 proto=17 src=0.0.0.0 dst=10.1.x.x sport=0 dport=1081
> PERMANENT
> 
> Is it correct that the source is 0.0.0.0 in both cases?

Yes, that's correct since you specified sip_direct_signalling=0.