Issue with Centurylink SIP -

[Mino IT]

We have a 3cx v16.2 instance in Azure ( Deployed via Azure Marketplace) connecting to CenturyLink

added the 9000-10999_UDP Rule into Azure

we have followed the instructions at https://www.3cx.com/docs/centurylink-business-sip-trunk/

and the Trunk Registers

but we cannot call out -
Activity Log shows -
08/05/2019 1:13:07 PM - Call to T:Line:10000>>[REDACTED]@[Dev:sip:[REDACTED]@voip.centurylink.com:5100] from L:2.1[Extn:906] failed, cause: Cause: 408 Request Timeout/INVITE from local
08/05/2019 1:13:07 PM - [CM503003]: Call(C:2): Call to <sip:[REDACTED]@65.149.36.87:5100> has failed; Cause: 408 Request Timeout/INVITE from local

i can call the Trunk Pilot Number and DID and it goes to my extension i can hear the external caller but external caller cannot hear me

attached is the nsg for the Azure VM

 

[leejor]

Does the 3CX Firewall Checker all pass? Usually any blocked ports will prevent audio incoming, not outgoing, so there maybe something else at play here.

The 408 message would seem to indicate that 3CX was unable to "locate" the Centurylink server. Could there be something in the network blocking this?

When I try a Tracert on voip.centurylink.com , I get 155.70.55.192 using DNS 8.8.8.8

 

[JohnS_3CX]

Hi @Mino IT

Just as the PBX has its own inbound audio ports, the provider also has theirs.

• Firstly, has the firewall checker passed?
• What do your outbound port rules look like?

 

[KeithTX]

We are using CenturyLink. CenturyLink and Level3 merged last year (or the year before), the CenturyLink SIP trunk listed on the 3CX website is not their current SIP trunk product. I have ours setup as a generic trunk with ports 5000-28998 for UDP and 5001, 5090 for TCP open on the firewall.

 

[Mino IT]

Hi @Mino IT

Just as the PBX has its own inbound audio ports, the provider also has theirs.

• Firstly, has the firewall checker passed?
• What do your outbound port rules look like?

Hi John,

Firewall Check - Passed
Outbound is all allowed

 

[YiannisH_3CX]

Hello @Mino IT

Please navigate to your trunk settings / Options and enable the option "Put Public IP in SIP VIA Header".
Click OK to save the changes and try again. Let me know if that makes any difference.

 

[Mino IT]

Hello @Mino IT

Please navigate to your trunk settings / Options and enable the option "Put Public IP in SIP VIA Header".
Click OK to save the changes and try again. Let me know if that makes any difference.

Hi Yiannis,

Tried and no change

 

[YiannisH_3CX]

In that case i would contact CenturyLink and ask them what they see wrong in their side. Perhaps they see something wrong in the traffic going to them and can point you to the right direction.