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New Member

CM - Inbound calls receiving busy signal

Recently I've discovered that if I down publisher OR subscriber I can't receive any calls from outside the VLAN. Calls can be placed out, they can be placed and received within the VLAN, but nothing on the outside can come in. All outside parties get when they dial any of my number is a fast busy.

CallManager 3.2.3



With Sub and Pub up everything works just fine.

Has anyone encountered anything like this?

  • Other Collaboration Voice and Video Subjects

Re: CM - Inbound calls receiving busy signal

it probably has to do with your gateway not registering to the backup ccm server, verify your mgcp, or h323 gateway is configured correctly.

New Member

Re: CM - Inbound calls receiving busy signal

I've been through

The only thing odd that I can see is that within CM, Device, Gateway, the registration status of the gateways is unknown?

Cisco Employee

Re: CM - Inbound calls receiving busy signal

sounds like it is an H323 gateway and you need to configure the gateway to register with the backup server if the primary isn't available.


Re: CM - Inbound calls receiving busy signal

It is normal for the registration status to be "unknown" for H323 Gateways, because the H323 gateways do not need to register with Callmanagers. Redundancy for H323 gateways is done using multiple dial-peers. Using the "preference" command in dial-peers, you can choose the order in which the Callmanager are selected for a call.

Could you please paste the configs of the gateways.

New Member

Re: CM - Inbound calls receiving busy signal

What you need to do is create a voice class and apply it to to your dial-peer.

I think by default the hunt process from 1 dial-peer to the next takes 30 seconds this is obviously not suitable if the primary CM is down as the ISDN call-setup will fail.

set the h225 timeout tcp establish to 3 and apply it to the first voip dial-peer that points to callmanager.

If the call cant be established to the primary CM'S Ip address whithin 3 seconds it will hunt to the second voip-peer and the call will get established.

Here is a link.