CUCM Trunk Service down to VGW router

[Yannis94]

Hello team,

Hope you are all doing fine!

I am struggling with a very odd problem and would gladly get any help or ideas from you.

I have inherited from the previous IT a Cisco call manager infrastructure with two isr4321 Voice gateways in HA mode.

3 months ago the trunk that we have from the call manager to the primary VGW stopped working and I got the error 503 on the call manager and the cause code 38 on the VGW.

I tried everything I know(let's note that I am a starter on voice cisco services) and the problem was suddenly resolved when I changed the HSRP priority, the backup router became the primary and the trunk was back on service.

Since Friday I get the exact same problem with my second router too. 

Just to let you know that the configuration for the sip services has not been changed for more than a year now, except for some changes on phone devices names, etc.

Does anybody has ever came through a problem like that or do you believe this could be a H/W problem?

[b.winter]

What's your config in CUCM?

Do you have 2 trunks? Or do you have 1 trunk?

To which IP(s) do the trunk(s) point to?

Sounds to me, that the SIP trunk is pointing to an IP (VGW), where the SIP service is not active, since the router is not the primary.

Is the HSRP working correctly?

[Yannis94]

Hello,

Thank you for your response!

I actually have 3 trunks as you can see in the attached picture.

The primary router's IP is 192.168.100.8, the backup is 192.168.100.9 and HSRP IP is 192.168.100.10.

Yes, I have verified that the HSRP is working.
Just for your information, the site is working fine with the backup router for the last 3 months and the primary is out of power because of a power supply failure that I have not received the spare part yet.

But suddenly it stopped and is shows me the same errors with when the primary was working.

[b.winter]

I'm not completely familiar with the HSRP config.

But normally, only the active router is able to send / answer SIP messages and also only on the virtual IP (HSRP address).

So in CUCM, you would only need one trunk, that points to the HSRP address. Since both routers don't listen for SIP on their "physical" IP.

Over which trunk (IP) do you send the calls?

Do you have a SIP trace of the VGW?

E.g.

debug voice ccapi ind 1

debug voice ccapi ind 2

debug voice ccapi ind 74

debug ccsip messages

[Yannis94]

Hello,

The calls are sent to the HSRP IP(192.168.100.10) .

I am attaching, some logs and the config we have implemented and I hope it is helpful.

[Sadav Ansari]

Try to ping HSRP VG IP from cucm and Visé versa and collect application and event viewer logs from RTMT since issue persist.

Is SIP Trunk showing not is service or what ?

Pls rate if its “Helpful”. If this answered your question pls click “Accept as Solution”.

Sadav Ansari 

[Roger Kallberg]

I agree with @b.winter you should only have one trunk in CM that points to the HA (HSRP virtual IP).

Have a look at this document for details on how to configure HSRP on a voice gateway, it is specifically for an SBC (Cube), but it should be applicable for a traditional TDM gateway as well.

[Nithin Eluvathingal]

As @b.winter mentioned You must have only one trunk to your HSRP IP

2.12.0.0

[Yannis94]

Thank you all for your replies.

After your recommendations, I made some changes to the config and now there is only one trunk to the HSRP IP but unfortunately, the outcome is still the same.

[Nithin Eluvathingal]

The Picture which I shared is asper the Cisco Press book .

Asper the press Book. 

"HSRP redundancy is not inherently stateful but can support stateful failover if the higher layers of software support application-level checkpointing and the basic router keepalive."

https://www.ciscopress.com/articles/article.asp?p=1567219&seqNum=9

I think you need to use  cube  Box to Box Redundancy solution doucemnt  which @Roger Kallberg  shared.

[Scott Leport · Accepted solution]

Hi there,

I think this line highlighted here is quite pertinent to your issue:

Jan 31 15:43:27.575: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Sent:
SIP/2.0 503 Service Unavailable
Via: SIP/2.0/TCP 192.168.100.11:5060;branch=z9hG4bK3fcd344eb686
From: <sip:192.168.100.11>;tag=66574501
To: <sip:192.168.100.10>;tag=100F9E44-6AC
Call-ID: 86d23f00-1f81039f-3fc0-b64a8c0@192.168.100.11
Warning: 399 192.168.100.9 SIP service disabled
CSeq: 101 OPTIONS
Reason: Q.850;cause=38
Content-Length: 0

You might want to double check your Smart Licensing between this gateway and your Smart Licensing server. If the CUBE / Voice gateway doesn't check in after a period of time, the SIP service stops and won't start until it successfully checks in with a licensing server.

[Yannis94]

Hello,

You are absolutely right.

That was the cause of the problem.

Thank you very much!!