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Support of Basic Calls between UC500 Series and 3rd Party PBX


What are the capabilities of the UC500 Series to support basic calls between itself and a 3rd party PABX via IP (H.323).

The Background:

We have a corporate Telephone network, with multiple sites and offices around the world. Everything is linked together via satellite, consequently we have an internal extension numbering system and a number of common standards to conform to.

I have a number of warehouses and workshops that require internet and phone connectivity. These are generally within microwave link range of a Regional Office with direct VSAT access to the international corporate network, providing access to the corporate phone system and intranet systems, web applications etc.

Local ISP and phone providers are unreliable, an independant system is desired.

The Sub Offices are equipt with BP250 PABX which can provide basic call support to 3rd party PBXs via H.323.

The UC500 Series is attractive because in one box with a microwave link I can provide staff with internet connectivity to the corporate network without VPN etc. It will also provide a stand alone phone system, with PSTN connectivity in the event of link failure.

What I really need it to do (and I haven't been able to find any docs to confirm) is link to the PBX in the regional office, via microwave link, ie, the 10/100 WAN uplink Port, and extend the corporate phone network.

I can see how it can be done via the PSTN interfaces, but this doesn't help me (why is a long story).

Thanks in Advance

William Twyford

Hall of Fame Super Gold

Re: Support of Basic Calls between UC500 Series and 3rd Party PB

That should work, if you PBX was of a more know brand Cisco also has interoperability configuration guides. Just set a small lab for testing and you should be good to go.

New Member

Re: Support of Basic Calls between UC500 Series and 3rd Party PB

I agree, it looks and smells like it does, but I can't find any documentation. (my fault probably, but I've spent a couple of days on it)

For Further information, the regional office PBX is an Ericsson Business Phone 250. Orange Pack licence- IP Networking for basic (transparent) support of IP Telephony.

Blurb from Manufacturer:

"Due to the implementation of Annex M.1 as part of H.323, the protocol mechanisms allow tunnelling of QSIG messages within H.323 call signalling channels. Therefore, this solution can be used to transparently couple BusinessPhone systems and 3rd Party PBXs through Anexx M.1 aware VoIP Gateway equipment over IP backbones."

"Using H.323 as IP Networking protocol enables integration of small branch offices including local breakout possibilities. This means that any H.323 (at least version 2.0) tunk gateway can be connected in a branch office via the corporate IP network, and can be used as a local trunk breakout."

So I have the capacity to do what I want to do at the regional office.

The CISCO data sheet for the UC500 Series references H.323 in two places, firstly on FXS ports to support fax machines, and secondly, in the PSTN interfaces and features section, "H.323 trunks with H.450 support"

I'm looking for documentation that confirms I can hook these two together for basic telephony via corporate network. (Can live without centralised billing and advanced features)

Re: Support of Basic Calls between UC500 Series and 3rd Party PB

Hi William,

This is supported on the UC520. It has limitations regarding CUCM for various reasons, but interop with 3rd party devices should be alright. It's not all too common, but you should be able to classify the UC520 as a H.323 gateway like any other IOS router in this regard.

You probably won't find any explicit documentation stating this.

Hope this clarifies.


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