CUCM H323 gateway

[KarolineSoares76078]

Hello everyone,

I'm having trouble with CUCM and H323 gateway operation.

It's not a new setup and it worked before but now I'm seeing that H323 gateway is not showing the IP address on CUCM.
I know that it's normal to show Status as Unknown, but IP address is also Unknown and inbound/outbound calls are not working.

I checked gateway config and CUCM config and they are correct. There are other H323 gateways working with this CUCM.

Tried to reset H323 gateway on CUCM and configure H323 again on the Cisco router, but nothing changed.
I validated that there's connectivity between gateway and CUCM, they can ping each other and port 1720 is open.

I made an inbound call and can see that gateway selects the correct dial peer, on H323 logs, router is making a request using correct IP address to CUCM, but on CUCM SDL logs, I can't find anything that tells me what could be the issue.

Did you guys had any similar issue and could give me any tips?

[Leonardo Santana]

Hi Karoline,

Your interface IP Address is different from the h323-gateway voip bind srcaddr.

Could you configure the same IP at both?

[Dmytro Benda]

Hi Karoline, 

The logs you provided doesn't match in time. The call from the VGW is shown at 15:12:30, while you show the part of the CUCM log at 15:07. May we please see what happens in your CUCM at 15:12? 

The VGW log shows that the VGW sends H225 Setup to 10.50.0.3:

Sep 28 2022 15:12:30.586 BR: //885/5516385D88B0/H323/generic_send_setup: src address = 10.50.249.254; dest address = 10.50.0.3

But then in 15 seconds the VGW sends H225 Release because the H225 connection timer expires (by default it is 15s):

Sep 28 2022 15:12:45.594 BR: //-1/xxxxxxxxxxxx/H323/cch323_timer_dispatch: Timer[CCH323_H225_CONNECTION_TIMER] expired
Sep 28 2022 15:12:45.594 BR: //-1/xxxxxxxxxxxx/H323/h323_set_release_source_for_peer: ownCallId[885], src[6]
Sep 28 2022 15:12:45.594 BR: //-1/xxxxxxxxxxxx/H323/h323_set_cc_cause_for_spi_err:
Categorized cause:102, category:129

Sep 28 2022 15:12:45.594 BR: //885/5516385D88B0/H323/cch323_h225_send_release: Cause = 102; Location = 0
Sep 28 2022 15:12:45.594 BR: //885/5516385D88B0/H323/cch323_h225_send_release: h225TerminateRequest: src address = 169774078; dest address = 10.50.0.3

So it seems, that your CUCM doesn't see the H225 Setup for some reasons. Check please the following:

- Isn't there any firewall/ACL restrictions for port 1720 TCP/UDP traffic between VGW and CUCM?
- Is the IP address of your H323 gateway configured as 10.50.249.254 on the CUCM side? 

Also I see in VGW config that you set UDP transport for H323. Did you try TCP?

My Cisco Unified Communications Blog

[Nithin Eluvathingal]

Is there a firewall in between CUCM and gateway  ? if yes i would ask to chek the firewall first. if there is any inspections disable it.

i can see cause code 18  which will be no user responding. I expect some issues communicating with CUCm using h323 protocol.

2.12.0.0

[Maren Mahoney]

The IP address shown in the "Device Name" field in CUCM is the IP address that CUCM will signal to (and accept signaling from) the H323 gateway. What appears in the Device Name field in the H323 GW in CUCM?

If no IP address (or the wrong IP address) is shown in the Device Name field on the H323 GW configuration page (which is what I am inferring from your question) then CUCM won't communicate. And, as has been pointed out, the IP address in CUCM must match the h323-gateway voip bind srcaddr in the router.

Maren

[KarolineSoares76078]

Hello Maren,

The IP address in CUCM matches the h323-gateway voip bind srcaddr in the router.
I tested connectivity between CUCM and the gateway and made sure that port 1720 is open, but H323 gateway on CUCM was still showing as Unknown.
After a restart of Call Manager service, H323 gateway started showing the correct IP address and external calls are working again.