Phones loses registration in the PBX

[Mitch Keijbets]

Hi,

I hope you can help with some really weird 3cx issues. We have a customer with yealink t27 phones and a 3cx v15.5 pbx.

And for some reason after a day give or take the phone is not getting/making any calls. We have to reboot it to get it working again. Before te reboot we can see in the phone gui that it is registered. But when we look in 3cx under phones the extension/phone does not show up. After the reboot it does and it works again.

We use yealink t27 with the supported/latest firmware, 3cx is up to date and we use an SBC. Does somebody know a fix for this issue? Please let me know so I can resolve it at my customer

 

[eddv123]

Hi Mitch,

How many Yealinks are running across this SBC ?

What version of the SBC are you using ? If Linux or Raspberry Pi please locate the OS with the command: "cat /etc/debian_version".

If using the SBC for Linux or Pi when this issue occurs instead of rebooting the phone can you run the command: "service 3cxsbc restart" within the SBC - or restart the service if using the Windows version.

I would like to see if the issue lies with the SBC specifically.

 

[Mitch Keijbets]

Hi eddv123

All of the phones are connected to the SBC. 17+ IP phones. SBC is ran on a windows server 2008 R2 server. Could the SBC be our problem?

 

[eddv123]

Hi,

I would doubt it now- not if you are using Windows, the Windows variant supports up to 50 extensions where Raspberry Pi can only run 20.

I would check the restart of the service as a test regardless, also check on the machine you are running the SBC from that you have no Windows firewall or Antivirus software that could be interfering. Also check your .NET Framework is up-to date also.

It maybe worthwhile running a PCAP trace from the phones (when in this state) to see what the issue could be: http://forum.yealink.com/forum/showthread.php?tid=1319

 

[simply7]

A packet capture will help in this case. If you want to watch realtime you would want to capture traffic between the phone and the switch and look to see if registrations are being sent from the phone to the PBX. You may want to run one on the server as well and make sure that the SBC is receiving and responding to the registration requests. Also a capture of the PBX as well to see if those messages are being sent as well. I am unsure if you will see them using the SBC however, if those messages are sent via the tunnel they may be encrypted. But I would start from the end point and work your way to the PBX. If you need a switch to do the port mirror may I suggest this one.
https://www.neweggbusiness.com/product/product.aspx?item=9b-33-122-614

 

[Mitch Keijbets]

The issue is I can't reproduce it manully. It just happens. Normally in evening/night (after office hours). So you suggest when the issue is happening I need to reboot the SBC service on the windows server. This SBC service reboot does this affect any active calls or active registrations?

 

[Saqqara]

What version of SBC - maybe upgrade to latest version https://www.3cx.com/blog/releases/session-border-controller-sbc-update/

Yes, restarting the SBC services will stop all active calls

 

[eddv123]

Hi Mitch,

Yes it would as this is the connection from the phones to the PBX and back. However if (as you say) the issue occurs out of office hours then this should not be an issue.

 

[Mitch Keijbets]

My guess is that the SBC needs to be updated. I will see if I can perform this after hours. Will keep you posted.

 

[Mitch Keijbets]

SBC has been updated. But a user had to reboot her phone. Strange thing is that my log of the sbc is not being updated.

Could this be a setting issue?

Type=file # cout, cerr, file, syslog
Level=ERR # "ERR", "NONE", "EMERG", "ALERT", "CRIT", "ERR", "WARNING", "NOTICE", "INFO", "DEBUG", "STACK", "ERR", "VERBOSE"
File=C:\ProgramData\3CXSBC\Logs\3cxsbc.log

 

[YiannisH_3CX]

You will need to replace ERR with VERBOSE for the SBC to collect detailed logs. Once you do that restart the SBC service to start logging.

Type=file # cout, cerr, file, syslog
Level=VERBOSE # "ERR", "NONE", "EMERG", "ALERT", "CRIT", "ERR", "WARNING", "NOTICE", "INFO", "DEBUG", "STACK", "ERR", "VERBOSE"
File=C:\ProgramData\3CXSBC\Logs\3cxsbc.log

 

[Mitch Keijbets]

Will try this at the end of the day and report back. Thanks!

 

[Mitch Keijbets]

Okay got some new intel. When I place the phones on STUN they don't seem to lose the connection. But they then have no dial tone when calling. The phone connects but without a dial tone. They are using Yealink t27 with recent firmware.

 

[NickD_3CX]

STUN works quite differently and the reason you are not getting any dial tone could be because you have not opened any ports on the firewall at the location where the phones are at.

On the SBC though, I agree with the comments above, packet captures on the server and SBC would probably shed light on what is happening. The SBC logs are a welcome addition too.

I think that is where you should start, especially if you are having trouble with STUN as well. There may be some other underlying issue affecting both in the end.

 

[Mitch Keijbets]

The issue is that it does not happen all the time...and the SBC log grows. Very fast. What ports do I need to open to get the dial tone up and running? And on the customer firewall or the VPS firewall?

 

[NickD_3CX]

The issue is that it does not happen all the time...and the SBC log grows. Very fast

Indeed, as will the capture files probably, but unless this is a really old PC, I would imagine that the HDD has 50-100GB of free space, which should be more than enough. We do recommend the SBC being a dedicated machine.

What ports do I need to open to get the dial tone up and running? And on the customer firewall or the VPS firewall?

the key points of settings up multiple Remote STUN extensions at the same remote site are the following (the proper way):
1) In the Management Console each Remote STUN Extensions must have a unique Local SIP Port and Unique RTP Port range and the RTP Port range must be 10 ports (for Yealink phones 12 ports) per remote site. This means that if we only had Yealink phones that would be e.g.:
- Ext A should have Local SIP Port: 5065 and RTP Port Range: 14000-14011 (12 ports)
- Ext B should have Local SIP Port: 5066 and RTP Port Range: 14012-14023 (12 ports)
- Ext C should have Local SIP Port: 5067 and RTP Port Range: 14024-14035 (12 ports)
- Ext D should have Local SIP Port: 5068 and RTP Port Range: 14036-14047 (12 ports)
- etc...
2) Once you have done this, then on the Remote Location Router/Firewall behind which the phones are residing, you must:
- Disable SIP ALG or any similar port remapping feature.
- Create NAT/Port Forwarding Rules so that, as per the above example:
--- Ports 5065 TCP/UDP and 14000-14011 UDP are forwarded to the IP of Ext A
--- Ports 5066 TCP/UDP and 14012-14023 UDP are forwarded to the IP of Ext B
--- Ports 5067 TCP/UDP and 14024-14035 UDP are forwarded to the IP of Ext C
--- Ports 5068 TCP/UDP and 14036-14047 UDP are forwarded to the IP of Ext D
--- etc...
- This also implies that the the phones/endpoints should have Static LAN IPs assigned to them.
3) Reprovision all Phones.
4) For all Remote STUN Extensions, go into the Management Console --> Extensions, edit the Extension, and in the "Options" tab, check the "PBX Delivers Audio" option, then press OK.
5) Make sure the Firewall Checked of 3CX passes