Unable to use direct calling to specific SIP number

[GoogleCodeExporter]

What steps will reproduce the problem?

1. configure "Direct" SIP provider
2. dial phone number sip:904@mouselike.org (free test number found on voip some 
site)

// seems to work fine

3. dial specific phone number via SIP with sip:+4179...@my.large.telco.domain 
(please contact me by email to get the private access phone number)

// request times out (408/Request Timeout)

4. dial specific SIP account sip:firstname.lastname@my.large.telco.domain (as 
listed in private Active Directory)

// request times out (408/Request Timeout)

I tried to look at the diagnostics and it seems as if the INVITE is indeed 
sent, but the other party never responds. I can supply the diagnostic log by 
email, upon request.

Generally speaking, "something" seems work as I can use Lync 2010 on Windows to 
make a call to the person (but this might be due to being authenticated on the 
network *and* using an internal and an external server (Lync terminology, also 
present on Lync 2010 for Android).

What version of the product are you using? On what operating system?

r1841 on Samsung Galaxy Note N7000, Android 4.03 (Samsung).

This might all be a mess to debug and identify, because there are too many 
variables. I do not have a channel to a contact within @my.large.telco.domain 
so I cannot tell whether calling sip:firstname.lastname@my.large.telco.domain 
should actually work (when called from the outside).

I have tried turning on TLS, but that did not seem to have any effect.

Original issue reported on code.google.com by stefan.h...@gmail.com on 27 Aug 2012 at 9:09

[GoogleCodeExporter]

Hi Stefan.

I mark issue closed because probably not a problem with the app, but more with 
configuration/network. But I'll try to give my thought to solve/understand the 
problem.

I guess that when you tell "Direct" SIP provider you are using the special 
local account.
In this case the app will just listen on port 5060 and place calls directly to 
the contact you specify without using any sip server.

As consequence the fact the remote server will reply will depend on how it's 
configured and there is many things that can lead to not have any reply from 
this sip server.
 * The first obvious possible root cause is indeed something with credentials. Some sip servers only allow calls from users of their domain. So as with local account you are calling from your IP your call may be rejected by the sip server. Usually in this case the server should reply something to tell we are not authorized however.

 * The second possible root cause is if the server tries to reply by its own without reusing the socket opened. As your sip client is probably on a private network it will announce it private IP to the server that is obviously unable to reach an IP in a private LAN. To wokaround that several approach could be tried. For example activating STUN could eventually help. 
Alternatively using another transport if supported by the sip server could do 
the trick. As you have a local account you need to force the use of the 
transport while dialing. So dialing something like 
sip:firstname.lastname@my.large.telco.domain;transport=TCP or 
sip:firstname.lastname@my.large.telco.domain;transport=TLS
I'm not sure however that local account of csipsimple is not bound to UDP 
transport only so not totally sure it will work. But interesting to try.

 * Another reason could be a firewall in the middle (more likely on my.large.telco.domain side since you are able to call the test number on the other domain) that blocks sip calls.

Did you succeed to do the same kind of thing with a desktop sip client? If so 
which and what is the configuration, maybe it could help to deduce the good 
configuration to setup for csipsimple.

Original comment by r3gis...@gmail.com on 27 Aug 2012 at 10:18

• Changed state: Done