Impact of Changing a User's SIP Address

If the left-hand side of your users’ SIP addresses contain a common user attribute in Active Directory such as first name, last name (or both) there is a good chance the SIP address will need to be updated to match any change in the corresponding user attribute(s).

The thought of changing an important attribute like the SIP address made me a bit uneasy and wondering what the impact would be. Specifically, after the SIP address change, would communication still work with another Communicator user who had previously added the old SIP address into their contact list?

After being involved in a deployment that did a few SIP address changes, I am pleased to report that there were no major issues. The seamless communication is made possible by OCS storing user contact lists by unique-id instead of SIP address. Here are some important points to consider however:

1. One of the biggest issues that could arise is that Office Communicator integration with Outlook will break if the user’s SIP address does not match the primary SMTP email address in their Outlook profile (see previous post “Office Communicator 2007 and Outlook 2007 Integration Errors”), so the primary email address will need to be updated to avoid this error. If you do update the primary email address to match the new SIP address, ensure that the user’s Outlook profile gets updated. The Microsoft Exchange Autodiscovery service can auto-update the profile if you have Exchange 2007 or 2010 deployed.
2. Users will need to restart Communicator after the SIP change. Outlook should also be restarted to ensure integration functions correctly.

Note, the SIP address change was not tested with the OCS Group Chat functionality. If anyone has experience with this, your feedback is appreciated.