I want to be able to call an H.323 endpoint from my SIP endpoint using the H.323 endpoint's E.164 number. How do I configure my endpoints or VCS to enable this?

Introduction

This article relates to the Cisco TelePresence Video Communication Server Expressway and Cisco TelePresence Movi products.

Q. I want to be able to call an H.323 endpoint from my SIP endpoint using the H.323 endpoint's E.164 number. How do I configure my endpoints or VCS to enable this?

A. In order for SIP endpoints and H.323 endpoints to be able to communicate with one another, there must be a VCS in the call route which will interwork the call between the two protocols.

SIP endpoints can only make calls in the form of URIs - e.g. name@domain. If you don't specify a domain, the SIP endpoint will automatically append its own domain to the number you dial. So if you dial 123 from the SIP endpoint, the search will be placed for 123@domain. If your H.323 endpoint is just registered as 123, then the VCS won't be able to locate the alias 123@domain.

The solutions are to either:

1. Ensure all your endpoints, both H.323 and SIP, register with an alias in the form name@domain.

2. Create a pre-search transform on the VCS that strips the @domain portion of the alias for those URIs that are in the form of nnn@domain. Refer to the Call Processing > Searches and Transforms section of the VCS Administrator Guide for information on how to configure transforms.

Related Information

• Technical Support & Documentation - Cisco Systems