SBC Register but Phone fail to register

[JohnS_3CX]

1. Disable account 1 on the Yealink and save.
2. Start pcap on Yealink (Settings>Configuration>PCAP)
3. Enable Account 1 and save
4. After 30-40 sec. go stop the pcap and download it

When opened in wireshark you should see the phone source IP send REGISTER to destination of the SBC IP at port 5060.

Does it send it and does it get an answer back?

 

[K_SAK]

I did change the logs to verbose but when I restart the

Do you restart the SBC service or reboot/restart the whole server?

 

[Alex Aubert]

I did restart the service : using this command
sudo systemctl restart 3cxsbc

I see from a phone pcap that my SBC doesnt reply

 

[JohnS_3CX]

Ok finally, you should also look up how to run tshark on your SBC and then restart the phone.

After the phone is up for a minute at least after startup, you can stop the tshark capture.

So now you are looking for the opposite, see if the REGISTER sent from the phone ever reached the SBC, and whether the SBC actually replied back but the phone never got it.

apt install tshark

tshark -i any -w capture.pcap

 

[Alex Aubert]

dont receive anything from the phone but if I ping this is replying

 

[Charles_3CX]

You’ll need to check the network configuration, as per the response in your existing ticket with 3CX Technical Support.

Please note that ping uses the ICMP protocol, which differs from how phones communicate using SIP on port 5060 over UDP. A successful ping does not guarantee that SIP traffic is allowed or correctly routed, so we recommend verifying that UDP port 5060 is open and not being blocked or filtered on the network or firewall.

 

[Alex Aubert]

On CBS220 - This option that block phone registration

Go to the "Security" section, then "Denial of Service Prevention," and finally "DDOS Security Suite."

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