Re: [Ekiga-list] Ekiga.net account with Android 2.3.4 native SIP-client

[Jānis Rukšāns <thedogfarted gmail com>]

On Fri, May 20, 2011 at 1:56 AM, Bart Vandewoestyne
<Bart Vandewoestyne telenet be> wrote:
> On Fri, May 20, 2011 at 01:32:03AM +0300, J??nis Rukš??ns wrote:
>>
>> > If I use my Android phone, then i have
>> >
>> > REGISTER sip:ekiga.net SIP/2.0
>> > Call-ID: 261a54f294918a1eae37a14f2dc7dc89@192.168.1.138
>> > CSeq: 8429 REGISTER
>> > From: "Bart.Vandewoestyne" <sip:Bart Vandewoestyne ekiga net>;tag=4156217873
>> > To: "Bart.Vandewoestyne" <sip:Bart Vandewoestyne ekiga net>
>> > Via: SIP/2.0/UDP 192.168.1.138:45061;branch=z9hG4bK686f4bc2b5692c50ca09b29d1f26e6283531;rport
>> > Max-Forwards: 70
>> > User-Agent: SIPAUA/0.1.001
>> > Contact: *
>> > Expires: 0
>> > Content-Length: 0
>> > [...]
>>
>> This is something I didn't expect at all - the message your phone
>> sends actually asks ekiga.net to unregister everyone from
>> sip:Bart Vandewoestyne ekiga net. I can only guess why.
>
> I'm not a SIP-protocol expert.  Can you explain me how you see
> this for the above message?  Is it because of the asterisk in the
> Contact header?  I have searched, but couldn't find the meaning
> of the * in the Contact header.

The * in Contact header is allowed only when unregistering (Expires:
0) and means every IP that is currently registered at the particular
address in To header. For example, if you have logged in from let's
say laptop and work, the above will force both of those clients to log
out (given that the server allows it).

>> It could be that the phone is trying to ensure it is only
>> device registered.  Whatever the reason, I expected at least
>> two REGISTER messages - the first with the private IP in both
>> Via and Contact (to discover it's public IP), followed by a
>> second one with the public IP in Contact.
>
> OK.  I'll play a bit more around, getting myself more comfortable
> with tcpdump and wireshark for my SIP-protocol debugging...
>
>> The unregister could be a bug, but it is also possible that the
>> phone is using it as a way to get the public IP, but doesn't
>> send the second REGISTER because of the 606 error code.
>
> OK.  And for as far as I understand it from
>
>  http://www.jitsi.org/index.php/Documentation/FAQ#ekiga.net
>  http://mail.gnome.org/archives/ekiga-list/2010-October/msg00040.html
>  http://mail.gnome.org/archives/ekiga-list/2010-October/msg00041.html
>
> ekiga.net should not sent this 606 error, right?
>
> So the conclusion is that the problem is actually on the
> ekiga.net server side and I have to hope that it gets fixed?

I'm not so sure about this particular case anymore (because of the
unregister), but in general, yes, it shouldn't. First, 6xx errors are
considered "global", and second, it definitely shouldn't give an error
on Via.

Like I said, the idea is to send the first message to discover one's
public address (the server inlcludes it in the response), and then
send a second one which should succeed. Keeping the private IP in Via
allows some server side tricks to traverse the NAT.

If you're willing to experiment, I can give you an access to my own
server at work (I'm using it for testing - writing SIP software is
what I'm getting paid for). You won't be able to call anyone but at
least we'll see if the phone sends the second REGISTER. Let me know if
you're up to that, I'll send you the details tomorrow.

Cheers
-- 
Ian