CUCM 11 and VG202XM MGCP - No Dialtone

[Ruslan Amrahov]

Dear Community members

One of our customers is running CUCM 11 and has VG202XM registered as MGCP gateway. All ports fot a status of "Registered" inside CUCM, however when users pick up handset of connected phone, they do not hear any dialtone. Outgoing calls are not working, but incoming do.

Please assist with troubleshooting of this issue.

[Manish Gogna]

Hi Ruslan,

Can you reset the MGCP gateway from cucm and do a no mgcp / mgcp on the gateway. If the problem persists please enable debug mgcp packets while recreating the issue and post it here along with gateway config.

Manish

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[Ruslan Amrahov]

Dear Manish

Thanks for your reply. Nothing was showing on these debugs. I think this is related to voltage as FXS cannot power idle the phone. Idle battery command is not found on the voice port. I changed firmware to the latest.

[Kunal Narula]

Hi Ruslan,

Can you validate whether fxs port is in loopstart ? if not , make it loopstart and run No battery-reversal under voice-port.

Thanks!

Kunal

[Ruslan Amrahov]

Hi Kunal

Thanks a lot for your reply. Unfortunately I did the same you advised, but it did not help. 

[Ruslan Amrahov]

Dears,

the issue was in incorrect dial-peer statements, as I had non-mgcp dialpeers with higher number before 989xxx-numbered mgcp dial-peers.

Thanks!

[Ruslan Amrahov]

Dear Manish

I actually opened case with TAC, they're asking for the same. But As I told before, this is due to voltage issue on the FXS port. Any ideas so far?

[Nadeem Ahmed]

Please post the show tech/Show run from VG.Did you collected any debugs yet for this scenario ?

Br,

Nadeem Ahmed

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[Ryan Huff]

Here are my thoughts; some of this you may have tried and some you may not have:

• This may sound silly but stranger has happened; can you make sure the phone's ringer/volume is on/enabled/Volume Up (if it has one)?

• Take one of the phones plugged into one of the FXS ports off-hook and while the phone remains off-hook type "sh voice call sum" in the CLI of the gateway. In the resulting output displayed, do you see the FXS port the phone is plugged into in the off-hook/waiting state? Also, while the phone is off-hook, does the LED for the FXS port show activity?

• Although you believe this to be a problem with the FXS ports themselves, when dealing with MGCP it is standard practice to reset the CCM gateway configuration and perform "no mgcp/mgcp" on the gateway as a basic troubleshooting method. Please try this if you have not already.

• By default, the idle voltage should be delivering -24v. You should be able to adjust this to -48v with "idle-voltage high" (unless you have two VIC-2FXS's in the VG, then I think you are stuck with -24v).

• Perform a "shut/no shut" on each of the FXS voice-ports if you have not already.

• Verify the FXS voice-ports do not have a PLAR configuration on them.

• When an inbound call comes in do you see something like "NO_RING_DESCRIPTORS" show up in the logs or via console (if you are in the CLI at the time with console logging on ... etc). If so, escalate to TAC (possibly bad hardware).

• Please paste/attach the following output in the CLI of the gateway:
• "sh mgcp", "sh ccm" and "sh inv"

Thanks,

Ryan

[Ruslan Amrahov]

Dear Community

We opened the case with a cisco, they changed VG with another one. The thing is that we bot the same issue with another VG, but only when I am using MGCP. When I configure it as a SIP device, it seems to be ok with a dialtone, but here the call is failing from VG to CUCM with 403 message coming from CUCM. SIP trunk with VG IP address was added to cucm.