Incoming call problem on 3CX Phone

[nicko31]

Hello, I'm located in the UK and am set up with two providers, VOIPFONE and SOHO66, I downloaded the free 3CX softphone from the US website. I have the phone registered and working and outgoing calls are no problem with both carriers. However, incoming calls are a different story. On both carriers they receive call intermittantly, often the VOIP fone does not ring and goes direct to voicemail. I get the same experience with both carriers, I've also tried installing on WinXP Pro and Win7 Pro on different machines, no change. My feeling it must be something straight forward, anyone got any ideas?

 

[leejor]

If the softphone seems to register correctly when first started (check the diagnostic log), then it could be that you need to shorten your re-registration time. your provider should be able to tell you what the minimum should be. be sure that you have STUN set up if you are behind a router.

 

[nicko31]

Sorry for my ignorance, how do I check the diagnostic log? Looking in my settings the registration time is set to 30 minutes. STUN server boxed is filled in with "stun.3cx.com"

 

[leejor]

It's the "debug" log, sorry. Click the round button at the bottom, then on Debug. It will show you what is going on in the background. 30 minutes is the 3CX default registration time and should be short enough. STUN setting defaults should be fine. If the initial registration works, then you have to find out why, perhaps, it is having problems re-registering. The phones main screen itself will show if it is no longer registered, look at the debug logs as soon as it happens. If it shows that you remain registered but cannot receive calls then you might want to ask your provider, for help, as to why they can't send the call to you any longer.

Are the calls now failing from behind one router, or do they sometimes fail, incoming, behind other routers?

 

[nicko31]

See below the debug log I have...

Attempting to connect sip.soho66.co.uk
Using network interface 127.0.0.1
Phone got as local port 55124
Integration with 3CX Call Assistant is ON
RTP engine OK
SIP engine OK
Sound mic device OK []
Sound ring device OK []
Sound play device OK []
Phone is sending STUN request
Phone online status is now 'Available'
Phone is now connected

 

[gpsjeff717]

Make sure you only have one SIP device registered to any given SIP account at any one time. Otherwise, unpredictable results may be encountered; especially for incoming calls.

When I have multiple SIP devices behind my router, I assign each device a different SIP port, even if they are registered to different accounts or sub-accounts. This seems to help avoid port conflicts - at least for me. While most SIP services default to port 5060, I find that they often support all ports between 5060-5065 (or, 5060-5069).

I note that Soho66 recommends "alternate" SIP port "8060" if you are having problems using port 5060.
http://soho66.co.uk/forum/default.aspx?g=posts&m=87

I also note that the 3CXPhone defaults to RTP ports 40000-40016. I change this range on my phone to match my cisco phones RTP range of 16384-16482, as my router is already set to Port Trigger open this port range on SIP ports 5060-5065. (I'm using my 3CXPhone with CallCentric.com and Voip.ms VoIP services, direct.)

I also see that Voipfone.com recommends a registration time of only 1 minute (60 seconds) and that they recommend the registration server use port 5060 and the Outbound Proxy use port 5065.
http://www.voipfone.co.uk/General_Phone_Setup.php
(It wouldn't surprise me if you could also try using alternate registration ports 5061 or 5062)