AT&T Sip hand off turn up - Outgoing works. Incoming doesn't.

[todd2021]

We've switching from AT&T Dedicated Internet and an ancient Nortel PBX to an AT&T sip handoff. During the initial turn up I was able to test that outgoing calls work but incoming with the test number doesn't. I have an Amazon Chime trunk installed also and it works fine.

V18 installed on a dual NIC dell server. One plugged into the AT&T router with one of our static IP addresses. No firewall in front of it at this point. The firewall test fails with:

• testing 3CX PhoneSystem 01 SIP Server... failed (How to resolve?)
  • stopping service... done
  • detecting SIP ALG... failed (How to resolve?)
  • testing port 5060... full cone test failed (How to resolve?)
  • starting service... done
• Everything else passes. Makes me think the AT&T router itself is blocking things. The second interface is at 1.1.2.12 directly plugged into port 8 of the Edgemarc 4008 router and the trunk is using the AT&T template pointing at 1.1.2.1

Can anyone using AT&T give some hints? They've asked that our "PBX contractor" be involved. Can I pay an hourly fee to have someone from 3cx sit in on a call and tell AT&T how to set up their router?

 

[jcostlow]

AT&T blocks SIP from the internet side of IP Flex and you have to make a MACD to open the SIP port for the firewall checker to pass.

If you run a packet capture while calling into the test number do you see the call?

 

[todd2021]

That's the thing. Wireshark on eno1 (external interface) shows sip packets when I make a call via the AT&T trunk.
If I switch over to watch eno2 (direct connect to port 8 on the at&t router) I'm not seeing any sip packets when I try calling the test number. If I ping 1.1.2.1 I see ICMP and ARP packets on eno2.

It's like the test number they gave me isn't actually routing to our router. Right now they're insisting on a PBX Vendor be involved so I'm at impasse with them unless I start yelling up the business sales chain.

 

[jcostlow]

What IP does your PBX have for the AT&T connection? I ask as your original post said 1.1.2.12 and they typically make it 1.1.2.21

 

[todd2021]

Sorry .12 was a typo. It's .21

inet 1.1.2.21/24 brd 1.1.2.255 scope global eno2
valid_lft forever preferred_lft forever