Yahoo is in the process of moving the location of their federation gateways. This change will prevent all Sametime Gateway deployments from establishing connectivity with the Yahoo! Messenger network.  To avoid possible service interruptions, firewalls protecting the Sametime Gateway must be updated or modified to accept incoming and outgoing traffic for the following hosts on port 5061:

• sgw.ibm.msg.vip.ac4.yahoo.com 98.136.112.84
• sgw.ibm.msg.vip.sp1.yahoo.com 98.136.56.113
• sgw101.ibm.msg.ac4.yahoo.com 98.136.113.23
• sgw102.ibm.msg.ac4.yahoo.com 98.136.113.24
• sgw103.ibm.msg.ac4.yahoo.com 98.136.113.25
• sgw104.ibm.msg.ac4.yahoo.com 98.136.113.26
• sgw105.ibm.msg.ac4.yahoo.com 98.136.113.27
• sgw106.ibm.msg.ac4.yahoo.com 98.136.113.28
• sgw107.ibm.msg.ac4.yahoo.com 98.136.113.29
• sgw108.ibm.msg.ac4.yahoo.com 98.136.113.30
• sgw101.ibm.msg.sp1.yahoo.com 98.136.43.128
• sgw102.ibm.msg.sp1.yahoo.com 98.136.43.129
• sgw103.ibm.msg.sp1.yahoo.com 98.136.43.130
• sgw104.ibm.msg.sp1.yahoo.com 98.136.43.131
• sgw105.ibm.msg.sp1.yahoo.com 98.136.43.132
• sgw106.ibm.msg.sp1.yahoo.com 98.136.43.133
• sgw107.ibm.msg.sp1.yahoo.com 98.136.43.134
• sgw108.ibm.msg.sp1.yahoo.com 98.136.43.135

This migration will be effective on April 24, 2008; therefore it is imperative that this change be made prior to that date to avoid any service interruption.  Aside from these firewall rules, there are no other application-related configuration changes required on the Sametime Gateway.

[ From IBM Technote 1303292]