Some users must try repeatedly before they can successfully sign on to Microsoft Office Live Communications Server 2003. Sometimes they are successful on the first attempt.

When their sign on fails, they receive:

Signing in to SIP Communications Service failed because the service is temporarily unavailable. Please try again later.

If these users specify the IP address of the Live Communications Server, they are successful on their first attempt.

This behavior will occur if the Live Communications Server has more than one network adapter. Users on one of the subnets will experience this difficulty.

Live Communications Server 2003 only supports one network adapter on the home server computer.

NOTE: Live Communications Server 2003 supports multiple network adapters on a computer configured as a front-end server, or a proxy server.

To workaround this behavior, remove the other network adapters, connecting the computer to only one subnet.