Recently, there have been some server changes made by two of our Public IM Connectivity partners Yahoo! Inc. and MSN (Windows Live). These changes will affect only those Microsoft Office Communications Server 2007 and Microsoft Office Live Communications Server 2005 customers whose external firewalls accept traffic on TCP port 5061 only from known IP addresses.
On May 22, 2008, Yahoo! Inc. moved their servers that provide instant messaging (IM) federation with Microsoft Office Communications Server 2007 and with Microsoft Office Live Communications Server 2005. As a result, The fully qualified domain names (FQDNs) and IP addresses for the Yahoo! gateway servers have changed. However, Yahoo! will not change the name of the service provider for instant messaging, which is configured in Microsoft Office Live Communications Server 2005 Access Proxy and Microsoft Office Communications Server 2007 Access Edge Server. This name will remain lcsap.msg.yahoo.com.
Meanwhile, MSN (Windows Live) has also changed the IP address for its LCS and OCS gateway. The name of the service provider for instant messaging will also remain the same, which is federation.messenger.msn.com.
As documented in the documentation for Live Communications Server 2005 SP1 and for Office Communications Server 2007, the recommended firewall configuration when federating with public IM providers is to allow any IP address to connect to port 5061 on the Access Proxy. However, certain enterprises prefer to enforce stricter firewall rules and restrict incoming connections to specific IP addresses. For those customers, the IP addresses that are used by the public IM networks need to be specifically allowed on the enterprise firewall. The following lists contain the new IP addresses that are currently used by each service provider:
IP address that is used by MSN (Windows Live)
IP addresses that are used by Yahoo!
IP addresses that are used by AOL (unchanged)
For further information about the Yahoo! Change, please refer to the following Microsoft KB article:
For other Known issues that occur with public IM connectivity, please refer to the following Microsoft KB article:
Sr. Program Manager