I recently received information that I thought would be useful to share with the community, also in attempt to prevent a lot of support threads asking why federation is no longer working with Microsoft! 🙂

“The federated edge server that supports Instant Messaging and conferencing with external companies will be migrated on Friday, May 9, 2014.

After the server migration, the IP address for the sipfed.microsoft.com SIP domain will change to 131.107.255.86. External companies who are federated with Microsoft may need to make changes to their infrastructure outlined under Instructions below in order for the federation to continue to function successfully.”

SUMMARY

Customers that originally configured their federation route with Microsoft to use an IP address will have to modify that entry and possibly firewall rules to ensure communications continue successfully.

INSTRUCTIONS

Depending on how their infrastructure is configured, they may need to make one of the following changes:

1. Companies configured as direct federations using IP address (not sipfed.microsoft.com) will need to update their configuration to the new IP address.
2. Companies using their firewall(s) to filter by IP address will need to update their Access Control List (ACL) to the new IP address

Note: External companies that are configured as an Enhanced federation and have configured their firewall(s) to Allow All (inbound and outbound) on TCP:5061 according to Microsoft’s recommendations will not need to make any changes.