STUN sever connection failure with some WiFi hotspots

What steps will reproduce the problem?
1. Come to a WIFi hot spot, where connection to the Internet is initially 
blocked (until you open a web browser and agree with ToS). After you agreed, it 
opens Internet and CSS registers itself fine
2. Try to make a call with any SIP server and watch for IP address in SDP. It's 
local - e.g. 10.200.6.109.
3. Confirm, that even call is established, the audio is not working

What is the expected output? What do you see instead?
Audio stream is working.
Instead, there is no audio.

What version of the product are you using? On what device / operating
system?
CSS r2430, Android, 2.2.2, HTC Aria

Please provide any additional information below.
After collecting and analyzing multiple logs it's clear now, that the problem 
is with the way how CSS gets its WAN IP data from STUN server. When hot spot is 
just connected, CSS tries to get WAN IP info form STUN server. It sends request 
several times and due to the restriction, imposed by WiFi controlling service 
(e.g. "Dragnfly" or similar), all the request packets are lost... After that 
point, even if Internet is opened and works properly, I can't make any calls. 
CSS simply doesn't even try to get WAN IP info from STUN server. In this case I 
have to do one of the followed things:
1. Restart CSS (Menu | Disconnect, then start it again)
2. Re-apply its settings (Menu | Settings, then go back)

Solution could be - if CSS failed to connect to STUN server and produced 
followed error:
"stunresolve  .Session failed because STUN Binding request failed: STUN 
transaction has timed out (PJNATH_ESTUNTIMEDOUT)"
CSS should try to send request to STUN server again before making next call. 
Why it's important? Because there is no much sense to make new call, if SDP 
contains a local IP. Even if the call will be answered, there will be no audio 
anyway...

Please try to connect to STUN server again, if the first attempt failed.

Original issue reported on code.google.com by yok...@gmail.com on 15 Oct 2014 at 2:48

Sanjivkumarroshan / csipsimple

STUN sever connection failure with some WiFi hotspots #2809