Yealink T33G Phones Show “No Service” via 3CX SBC While Grandstream Phones Work

Nevermind, i dont think it would make a difference.

Are you able to enable wireshark on the SBC and confirm you see the registration attempt from the phone?
 
Nevermind, i dont think it would make a difference.

Are you able to enable wireshark on the SBC and confirm you see the registration attempt from the phone?
we have Debian SBC Server..Here i can,t see registration attempt.only show phone which already registration
 
You'd need to stick your SBC into verbose logging and probably have to restart it. Try the phone registration, pull the logs off the SBC and then use Wireshark to check if the traffic from the phone is hitting it. If it isnt, then you have a routing issue.

you could also first try a capture from the 3CX mgmt console but if it doesnt hit it, you'll need to troubleshoot back from the SBC.

https://www.3cx.com/docs/capture-network-traffic/
 
i Attact the pcap file.