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T20 can not dial out - Printable Version

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T20 can not dial out - dede - 03-25-2015 07:10 PM

I have a Yealink T20P. Hardware version is and firmware version is
After "Reset to Factory Setting" I only changed the password for the WebGUI and set up
Account-1 to register the phone at my FritzBox.

Now I can call other (internal) phones, that are also registered at my FritzBox.
And I can accept/answer incoming calls from outside.
But if I dial an outside number, my FritzBox is calling that number, the called phone
does NOT ring and I get a sound for "line busy" on my Yealink T20P.

Another VoIP-phone (Netphone KE1020A) with the same settings on the
FritzBox (except account data) works without problems.

Which setting do I have to change, to be able to do outgoing calls?

Thanks in advance,

RE: T20 can not dial out - James_Yealink - 03-25-2015 09:23 PM

Hi Detlev,

There is no setting in phone to enable outging calls. After successfully registering an account you should be able to call out.
Can you please check whether the device is blcoked in your server?
You can try deleting and re-adding it to your server or create a new account for it.
And is there a log in your server?


RE: T20 can not dial out - dede - 03-25-2015 10:25 PM

Hi James,
as a test I unplugged the Netphone KE1020A and used its account for the YeaLink T20P.
No change: outgoing calls are not working.

My "server" (the FritzBox) is a router-box and there is no real log for telephone functions.
But there is a callmonitor.
For the KE1020A it shows:
25.03.15 15:04:41;CALL;3;20;04xxxxxxx06;01xxxxxxx49#;SIP0;
25.03.15 15:04:50;DISCONNECT;3;0;
...and my cellphone was ringing.

Doing the same with the T20P it shows:
25.03.15 15:07:22;CALL;1;21;04xxxxxxx06;01xxxxxxx49#;SIP0;
25.03.15 15:07:34;DISCONNECT;1;0;
...and my cellphone did not ring.
If my cellphone is near to another telephone, I can hear, that my cellphone is being contacted.
Normally, it rings a second after I hear this sound.
If I call my cellphone (laying next to the other phone) with the T20P, I hear the sound, then
the sound stops and the T20P brings the "line busy"-sound.

So...because of this behavior, I think its a protocol related problem.
The call goes out, the called device is being contacted but the session could not be established.


RE: T20 can not dial out - James_Yealink - 03-25-2015 10:48 PM

Can you please get a pcap trace/level 6 syslog/configuration file? We check call process through these files.

How to get them:

And are there any other Yealink device in yoru side?
Or you are tesing the compatibility between Yealink phones and FritzBox.
What's your FrtizBox version? In this post users successfully set up T46G with FritzBox.


RE: T20 can not dial out - dede - 03-25-2015 11:20 PM

Hi James,
the T20P is the only Yealink device here.
I'm not "testing the compatibility between Yealink phones and FritzBox" - I want to use the T20P with my Fritzbox.
My Fritzbox is a model 7390 and the Firmware is "FRITZ!OS 06.23".

I sent the requested files to your eMail-account (and forgot the config - attached here).


RE: T20 can not dial out - James_Yealink - 03-26-2015 12:57 AM


From the pcap trace:
1. You make a call to xxxxxxxx49.
2. You hear a ringback.
3. The ringback lasts for about 10s.
4. You cancel the call in phone manually?

Are these steps correct?
Phone send out an invite message and receive a 100Trying, 183Ring. The problem is that phone don't receive a 200OK message from the other side. Unfortunatelly we can't confirm the issue only in phone side since there is no an abnormal behavior to phone.

Can the T20 call Netphone KE1020A? I mean that use T20 to call an internal extension but a cellphone.


RE: T20 can not dial out - dede - 03-26-2015 01:37 AM

Hi James,
steps of the pcap trace:
1. I made a call to xxxxxxxx49.
2. I did NOT hear a ringback. The only thing I heard was a "radio interference" in a third uninvolved telephone near to the cellphone (an indication, that my cellphone was contacted).
3. After some seconds I heard a "line busy" sound from the T20P.
4. I canceled the call on the T20P.

I can call the Netphone KE1020A from the T20P.
The KE1020A rings and I can talk over this connection.
Do you want a pcap of such "session" too?

Everything is fine with the T20P - except that I'm not able to call external numbers.
But with the KE1020A, I am able to call external numbers. And this phone uses the same "technology" or infrastructure - so it has to be the T20P, that has the problem.


RE: T20 can not dial out - James_Yealink - 03-26-2015 01:57 AM

Can a pcap be got in Netphone KE1020A when doing an extenal call? It will be more helpful.


RE: T20 can not dial out - dede - 03-26-2015 02:16 AM

Hi James,
the KE1020A has a very simpe WebGUI and no option to trace.
This is the complete GUI with working settings (maybe you can see the difference to the T20P-config):
[Image: 1.png]
[Image: 2.png]
[Image: 3.png]
[Image: 4.png]
[Image: 5.png]
[Image: 6.png]

Hi James,
sent an email to you with a trace captured with a feature of the Fritzbox while doing a call to my cellphone. The first attempt was not successful, at the second attempt the cellphone rang and I was able to talk to myself in stereo (with a short delay) ;-)

RE: T20 can not dial out - dede - 03-26-2015 04:02 AM

Hi James,
now I captured two files with the Fritzbox.
If I only look at the lines with "Protocol = SIP or SIP/SDP", I get these two lists:

unsuccessful call with T20P
58 Request INVITE sip:.....@....
59 Status 100 Trying
60 Status 401 Unauthorized
61 Request ACK sip:.....@....
62 Request INVITE sip:.....@....
63 Status 100 Trying
330 Status 487 Request Terminated
331 Request ACK sip:.....@....

successful call with KE1020A
140 Request INVITE sip:.....@....
141 Status 100 Trying
142 Status 401 Unauthorized
143 Request ACK sip:.....@....
144 Request INVITE sip:.....@....
145 Status 100 Trying
151 Status 183 Session Progress
154 Request PRACK sip:.....@....
155 Status 200 OK
176 Status 183 Session Progress
177 Request PRACK sip:.....@....
180 Status 200 OK
411 Status 183 Session Progress
412 Request PRACK sip:.....@....
413 Status 200 OK
424 Status 180 Ringing
425 Request PRACK sip:.....@....
428 Status 200 OK
804 Status 200 OK
805 Request ACK sip:.....@....
1221 Request BYE sip:.....@....
1224 Status 200 OK