Yealink T19P E2 No sound

[daktur]

Hi All, it's me again!

I am trying to set up a remote location with 6 Yealink T19P E2 everything went good with the auto provisioning however when the extensions receive inbound calls, they have no sound. the caller can hear perfectly but the recipient cannot hear anything.

Outbound calls work fine.

It's not possible to use SBC and I have used the standard provisioning template.

Running v15.5 and all firmware updated to 53.82.0.20.

Any ideas?

Thanks!

 

[eddv123]

Hi Daktur,

Although not mentioned I will presume you are using these phones in remote STUN/RPS mode.

It sounds to me like your port forwarding is not setup correctly on your remote firewall, you need to port forward your RTP ports for 3CX: https://www.3cx.com/docs/3cx-phone-system-v14-ports/

Please also check if you have "PBX Delivers audio" enabled if it is a STUN extension.

Although you have said you cannot use the 3CX-SBC if using multiple remote phones in a single location I would always encourage the use of it for added security/encryption and ease of setup.

 

[daktur]

Dear @eddv123 ,

Thank for the information I tried both with PBX delivers audio on and off and the result was the same.

My server is not behind NAT but the remote location is. I see the phones listed with the remote site public up.

I sent the port information to the admin on the remote site and they confirmed the configuration was made properly.

Yet the issue persist.

I use this phone, same model, in different remote locations and they work just fine.

I even tried to set each phone for a different sip port I.e. 5065, 5067, 5069 and so on and set phones local RTP ports com 14000 to 15000. Should I set it 9000-9500 like the server and all phones local ports back to 5060?

I seriously thinking about not supporting phones on remote locations only the softphone.

Simply cannot make the phones to work in this remote site.

Hope you can help me to figure this out.

Thanks again.

 

[eddv123]

Hi Daktur,

If you were to use the SBC you would have a much better experience, personally I think STUN should be reserved for single remote phone deployment only (especially if you do not have full control of firewalls at both ends of the connection).

Is your firewall checker passing ? you can always try the remote client version if it is and you are still getting firewall/port forwarding related issues: https://www.3cx.com/docs/firewall-checker-client/

 

[YiannisH_3CX]

Hello @daktur

Each phone should have a unique sip port and a unique set of RTP ports. Try 12 ports for each phone. Example: First phone Sip port 5065, RTP ports 14000 - 14011. Second phone Sip port 5066, RTP ports 14012 - 14023. After these are set under the management console phones need to be re-provisioned. Also the ports need to be port forwarded at the remote sites firewall to the local P address of the phones.

 

[daktur]

Hi @YiannisH_3CX ,

I will do it and try again, not sure if possible to do the port forwarding however studying a way to implement SBC.

How should I update the provisioning file to use SBC instead of stun?

Thanks again.

 

[accentlogic]

daktrur,

Once you get the SBC setup, make and note of the MAC address and extension assignments, and then remove the phones from each extension and then factory reset them. (Press the OK button for ten seconds.) When the phones boot up the SBC will see them, and it will show up in the Phones tab of the console. Click to assign each phone to an existing extension, and it will automatically use the SBC - just change any other settings desired, such as the clock and screen settings, and save it. The phones will automatically re-provision.

For an SBC you can use any old Windows 7+ computer, a Raspberry Pi, or a fresh install of Debian. It can also be a virtual machine in Hyper-V or VMware. Either way, I would recommend making the SBC a dedicated device.

 

[daktur]

Dear @accentlogic @YiannisH_3CX

I installed the SBC in one location and it work just fine but i have a few questions:
1. How long does it take to update a phone once an extension is assigned?
2. Is it possible that once assigned the phone looses the configuration and needs to be reassigned?
3. What information should I use to provision an unsupported phone via SBC, if possible.

Thanks!

 

[YiannisH_3CX]

1. How long does it take to update a phone once an extension is assigned?

I assume you are referring to assigning a phone to an extension using PnP through the SBC. This could take up to 3-4 minutes depending on the phone and the network. Some phones need to also restart a few times before the provisioning is complete.

2. Is it possible that once assigned the phone looses the configuration and needs to be reassigned?

You mean that a phone got provisioned and then lost it's configuration? Did it revert to factory settings or did the phone disconnect?

 

[daktur]

Hi @YiannisH_3CX ,

Thank you for your reply.

Some phones need to also restart a few times before the provisioning is complete.

They do it by themselves or the user needs to restart them a few times?

You mean that a phone got provisioned and then lost it's configuration? Did it revert to factory settings or did the phone disconnect?

Yes, That's exactly what happens, the phone became available again to be assigned to a new extension.

Any information about what info to provide unsupported devices to connect via SBC?

Thanks!

 

[YiannisH_3CX]

They do it by themselves or the user needs to restart them a few times?

Supported phones provision and restart on their own. No need to user input.

Yes, That's exactly what happens, the phone became available again to be assigned to a new extension.

Have not seen this happen before to be honest. Do the phones provision correctly? Can you make and receive calls? Does this happen after a reboot or randomly? Are you using the latest SBC? Is it installed on Linux or windows?

Any information about what info to provide unsupported devices to connect via SBC?

No sorry, perhaps someone else can help you with but in general i would recommend always using supported phones

 

[daktur]

Hi @YiannisH_3CX

Have not seen this happen before to be honest. Do the phones provision correctly? Can you make and receive calls? Does this happen after a reboot or randomly? Are you using the latest SBC? Is it installed on Linux or windows?

I am using the latest version of SBC for windows. Maybe there were a lot of phones on the LAN and I was provisioning them using my mobile and did not give enough time for the information to update. Now they work fine.

BTW do you know how many devices should a RaspberryPi 3 SBC be able to handle?

Thanks again!

 

[YiannisH_3CX]

Glad to hear the issue is now resolved. As per guide you can have up to 20 phones behind a raspberry pi with maximum 10 blf's each.

 

[daktur]

@YiannisH_3CX ,

Now all the phones simply unregistered:



Could it be because there was a new IP assigned to the SBC? Have you ever seen this before?

Thanks again!

 

[accentlogic]

If the SBC changes the phones will do this, the SBC IP address will be different - best to use a static IP if possible on the SBC to avoid this. We have seen some carrier cable modems use a 1 hour DHCP lease that can't be changed so after a power loss different IP addresses are assigned as equipment comes back online. If your DCHP server supports a reservation you can do that, or at least change the lease to 8 days or more to avoid constant IP changes.

You can simply assign these "new" phones back to the correct extension, and the 3CX Plug and Play will tell the phone the new SBC address and reboot the phone(s).

 

[daktur]

Hi @accentlogic,

I will investigate the reason of the change,it was supposed to be fixed.

When I check the phone provisioning in the extensions settings it appears the new IP address where the phones are connecting from. Why it does not update automatically?

Thanks again for all the help!