Interop - Sending IP Calls to Cisco Gateway connected to NEC NEAX 2400

[csshenoy80]

Hi

We have a setup with  NEX NEAX 2400 using Cisco 3845 as Voicegateway, with E1s connected to cisco gateway for dial-out and dial-in from PSTN.

NEC--> Cisco 3845---> PSTN

Can we use this setup to send IP calls from Cisco CallManager to this PBX, that is, to establish IP Trunk with the NEC, with calls being sent to the Cisco Gateway.

NEC<-->Cisco 3845<-->IP Network<-->Cisco CallManager

Thanks.

[Adrian Saavedra]

Hello,

Yes, you can call from CallManager to NEC using the existing E1 connection between ISR and NEC. Configuration depends on which protocol are you using to control the E1. If using H.323 then you'll need to define a route pattern in CallManager and point it to the router's IP address and create a dialpeer in the router to send the call to NEC through the E1 port. If using MGCP to control that E1, then you only need to create the route pattern in CallManager.

Hope it helps,

- Adrian.

[csshenoy80]

Thanks Adrian for th quick response.

However, I am looking at exploring IP Options, that is, send IP calls to the PBX from Cisco CallManager by sending calls on the Gateway, to match the destination pattern on the Cisco GAteway and that call being answered by the extension connected to the NEC PBX.

The Cisco Gateway is connected to network and reachable on the Network to the Cisco CallManager, so trying to setup an IP Trunk.

[Adrian Saavedra]

You have two options:

1.- Configure an IP trunk (H.323/SIP) between CallManager  and NEC (if IP is supported).

2.- Configure your 3845 as an H323 gateway (Device -> Gateway) in CallManager. Create the route pattern in CallManager pointing to 3845 gateway.

Adrian.

[csshenoy80]

I have already setup it as H323 gateway on the CUCM, however when an extension on the PBX is dialed, it shows as connected, however i hear fast busy tone after the call is answered.

[Adrian Saavedra]

Ok, since you have a E1 between 3845 and NEC, can you take a debug isdn q931?

-- Adrian.

[csshenoy80]

I have dialed the PBX extension from Cisco IP Phone, being an IP call, isdn q931 debug will not provide the debug.

[Adrian Saavedra]

Ok let me understand better the topology

CM --- IP trunk --- 3845 --- PRI E1 --- NEC

or

CM --- IP trunk ---- 3845 ---- IP trunk ---- NEC

?

[csshenoy80]

The NEC PBX uses 3845 for PSTN connectivity. So question was Can we send IP calls sent on the Cisco Gateway, answerable by NEC PBX.

CM --- IP trunk --- 3845 --- PRI E1 --- NEC

[Adrian Saavedra]

Ok, you have a PRI E1 connection between 3845 and NEC. You're sending calls from CM to 3845 via IP trunk using H.323. When the call arrives to the 3845, the router will take control and send the call through the E1 port, then you can use debug isdn q931 to see what's going on.

- Adrian.

[csshenoy80]

Hi

Had figured out the issue. The CUCM configuration was fine and signalling was reaching upto the 3845 gateway, however the calls were not getting going throught / fast busy, as there was a in-correct H323 binding. A interface (in shutdown mode) was having the H323 binding on the 3845 gateway, causing the IP calls from Cisco CUCM to be lost.

The H323 binding was removed from the incorrect interface and binding was performed on the actual IP Interface for the device. This resolved the issue.

Thought of updating the forum as it might be helpful for others.

thank you Adrian for the suggestions.