Yealink T21P E2 - Specific one way audio issue

[mkasprzak]

Hi guys!

We've got a big problem in our company and I thought that maybe you could help us. At the beginning of the October, we've had a problem with our PBX that led us to hard disk replacement and setting up a fresh copy of FreePBX with Asterisk 13. Before this situation we were using very old copy of FreePBX, that was set up by another company, but it was working decently.

Now everything seems to be okay, but there's one thing, that we need to solve fast. We've got offices in one city, and a branch with call center in another. Each of us has its own PBX (the HDD was replaced in the one used by call center). PBX in call center is connected with GSM trunks (3 via IAX, 3 via SIP). PBX in our main location is connected to PRA/ISDN/digital lines. Both of these machines are connected to each other via IAX.

We've got a configuration that allows consultants in our call center to place calls via these digital lines, so it goes like this: consultant phone -> call center's PBX -> main PBX -> digital line. Also we do it the other way around, for example for IVR.

Internal calls in call center work fine, internal calls from CC to our main location work fine too, calls placed via GSM trunks also work fine for all phones too. The problem is that the employees that use two models of phones can't hear the dialed person (they hear the signal, but after call being answered, they hear nothing).

In our call center we are using three models of Yealink phones - SIP-T20P, SIP-T21P E2 and one VP530. The last two are the ones that have this problem.

The problem lies somewhere between PBX in call center and the phone. Why I think so? Because if you listen to the recording of the call, there are voices of both people recorded.

Another interesting thing is that SIP-T20P phones are displayed by Asterisk as registered on the port 5062, while the SIP-T21 are being registered on port 5060, but the VP530 phone registers on port 5062 as the SIP-T20P do, but it has the same problem as the SIP-T21.



Earlier I was thinking that this problem may be related to the fact, that in new version of FreePBX I've tried to use PJSIP instead of regular SIP, but switching back to the legacy SIP didn't help.

Do you have any idea how can we solve it? I'll provide any additional information if you'll need it.

Thanks in advance! You'll save my life if we can get rid of this problem

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EDIT:
I've tried changing local port to 5062 and enabling RPort in the phone settings. Now the phone registers on the port 5062, but it still doesn't work properly.

[Lucia_Yealink]

Hi Sir，

About your issue, in order to make your scenario more clear, let us check if the information are right below:

1. When there is an external incoming call, the employee can hear the call ring, but when they answer the call, they can’t hear any audio, right?
2. The internal incoming call work normally?
3. T21P E2 and VP530 have the issue, but T20P can work normally?
4. You listen to the record of the call, and find both voice of the two side are recorded, right? Can you kindly tell me how can you get the record?

In order to do more trouble shooting, please share us more information below:
1. Can you kindly provide the level 6 syslog, config.bin and pace trace of T21P E2 and VP530 for us when you reproduce the issue.
About how to get the three files, please refer to the link below:
http://support.yealink.com/faq/faqInfo?id=313

2. To make a comparison, please provide the level 6 syslog, config.bin and pace trace of the T20P.
3. When you get the pace trace, please also capture the pace trace in the PBX, since we can see the behavior of the server from it.
4. Is the issue happened every time when receive the external incoming call? If not? How often it will happen? Such as twice a day?
It would be better if you can provide the three files of the T21P E2 and VP530 when they can receive an external incoming call normally to make a comparison.

Please note to update the firmware of both phone to the latest firmware then do the test. You can download the latest firmware in Yealink website:
http://support.yealink.com/documentFront...isplayPage

5. How many phones you have in total? And how many of them have the issue?

Thank you for your information in advanced.

Best Regards,
Lucia Lu