Phone Extension Not Receiving Any External Calls...

[Kipsang]

Greetings Team,

I am new to this forum & I apologize in advance if this has been asked before. I have a Yealink PBX system here at work & the IP phone model we use is SIP-T20P. All the extensions are working except one which isn't able to receive external calls. I've checked the configurations & everything seems alright. Is there anything I missed? I'd really appreciate your help in solving the problem.

Warm regards,

Michael.

[Lucas1]

nice to contact you.
Thanks for your continuously support for Yealink products.
I read your description, but also dont know why the issue occur.
could you please to check some question.
1,Do all extensions register same PBX server?
2,Can this extension receive internal call ?
3,please configurate this extension with other account ,check the issue if still exist?

In addtion,Please provide more issue data to us for analysis from phone.
1,trace
2,syslog(level 6)
3,config.bin
if you dont know how to get issue data ,please refer to http address
http://forum.yealink.com/forum/showthread.php?tid=1319.