Showing results for 
Search instead for 
Did you mean: 

Use ip address to call endpoint/MCU(H323) registered on VCS


I find that if the endpoints or MCUs (h323) register on VCS, it is not able to call the ip address of them. Is this a normal situation or there are some settings I have to change to make it work?

4 Replies 4

Jens Didriksen

This is normal behavour, however, you can allow calls using IP addresses (but why would you?), by following the steps in this post:

We don't allow this as a lot of our systems are using DHCP, but the E.164 Alias is static, and works as both H.323 and SIP address, so no need for separate addresses. Also, using IP addresses becomes a tad complex if/when using IPv6.


Please rate replies and mark question(s) as "answered" if applicable.

Thanks. But if there is a h323 endpoint unregistered to any GK and it want to call the ip add of the endpoint registered on VCS, what shall I do to make it work?  Or this is a mission impossible?

So this end-point does not support H.323 Annex O dialling (Alias@domain)? What type of endpoint is it?

Do you have a VCS-C/VCS-E combination and is this endpoint external to your organisation?


Please rate replies and mark question(s) as "answered" if applicable.

Patrick Pettit
Cisco Employee
Cisco Employee

HI Cheng.  Would be nice to know what MCU, GK and endpoints your  referring to here.  If i take an MXP and turn off SIP and go direct mode  for H323, when I place a call to the IP Address of my MCU, the call  connects and I enter the Auto Attendant. 

So it would be nice to know if your running VCS and Cisco Codian MCU. 

1) Verify Search Rule configured for Any IP Address Targetting Local Zone. 

2)  MCU is set up to receive calls and enter the AA. Setting on 4.4 MCU is: Calls To Unknown Conferences or Auto  Attendants.

Have the H323 registration on MCU  enabled.  When the MXP places the call, the call routes directly to MCU,  MCU will then send ARQ to VCS.  Since VCS doesn't know about this call,  ARJ is sent with RouteCallToGK.  MCU sends Facility redirecting MXP to  call VCS.  Call then connects.  Call fails if Any IP Address Rule to  Local Zone isn't present. 

This is between these three  devices.  Not sure of what you have, so again I'm not sure, but like  Jens easier to register and just dial the E164 Alias. 



Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers