Direct SIP dialing & direct IP dialing question
azrobert:
I installed Linphone on a test computer connected to the same network as my OBi110.
I defined an SIP account on Linphone pointing to the OBi110 like:
SIP Identity: sip:robert@192.168.1.100:5060
SIP Proxy: sip:192.168.1.100:5060
Register: Unchecked
I dialed 0 on the Linphone.
The call was successful with 2 way audio.
I created a 2nd network by connecting the WAN port of a test router to a switch port on the original network.
I connected the computer running Linphone to the 2nd network.
I repeated the test.
The call was successful, but with 1 way audio.
I enabled Symmetric RTP on the OBi110's SP1.
I repeated the test.
The call was successful with 2 way audio.
I know this is not the same as calling from a hotspot, but this is how I diagnosed the problem calling from an Android/CSipSimple. I received similar results from Android/CSipSimple, but I believe there was no audio from a hotspot without Symmetric RTP enabled.
I'm running DD-WRT FW on both routers.
Edit:
When I was testing Android/CSipSimple I displayed the Call Status on the OBi110. It showed the RTP packets flowing in both directions. I'm not a network expert, but I think when there is a NAT problem you don't see the RTP packets flowing. This led me to try the Symmetric RTP.
ianobi:
Yes, I agree that Symmetric RTP is helpful in this direct ip to ip situation. Also, I enable ICE on both the OBi and CSipSimple and this helps for some networks that do not otherwise work.
It is difficult setting up test situations. From my home I can connect to a British Telecom wifi hotspot, so I can observe calls coming into my network and record them using Wireshark. Using this setup I have solved many problems, but then I go out to a coffee shop or pub and sometimes it does not work from their wifi hotspot ??? When visiting my brother I found that I had to enable "Aggressive ICE" on CSipSimple to make it work. There's lots of variations out there when it comes to wifi hotspots!
By the way, CSipSimple does have a good call logging facility. If you enable it, then it will log the SIP interactions during a call setup etc and place them in a folder on your phone called CSipSimple > Logs. Easier to view if you download them to a pc.
I may have a look at Linphone. There's not many softphones around that allow calling with no registration.
azrobert:
Quote from: ianobi on July 25, 2015, 10:21:59 am
I may have a look at Linphone. There's not many softphones around that allow calling with no registration.
When I started testing Linphone there was no audio.
Linphone was defaulting to the wrong Playback and Ring device.
Under Help/Audio Assistant you can test these settings.
Navigation
[0] Message Index
[*] Previous page