Yealink Forums

We bought 50+ Yealink T23G phones, about 10 of them lost connection randomly, refuse to reconnect for hours "Register Failed", but we can access the phone admin page.

We tried changing the IP, extension, etc.

After a couple of hours, the extension is back online. Based on some threats I found in this Forums, Im sending the System Log Level 6 of one of those phones.

Thanks in advance...

Sounds strange. Looking at the PCAP you posted I don't see the phone going online at all. You can see the SIP registration requests being sent from the phone (192.1.9.100) to the server (192.1.1.6), however there are no indications of a reply ever coming back.

Given that the phone and the PBX appear to be on two different subnets, you might want to check your routing and firewall for that location and see if there's anything strange going on there.

Also note that your config appears to show both server 1 and server 2 on the phone configured to the same server IP; do not do this, if you don't want redundancy simply leave server 2 blank, otherwise you'll end up causing more problems. This may be the source of your issues right now, it's hard to know again as the packet trace is not showing any kind of response...