Each Exchange Unified Messaging server can target a Lync Edge Server for when it needs to provide media relay to a remote user. By default, each Unified Messaging Server will request MRAS credentials from the first A/V Edge Server that sends it a request, but administrators can optimize this Edge Server selection through the Set-UMServer
cmdlet. The SipAccessService
parameter specifies an Edge pool name and A/V Authentication port to use. An example is provided here:
Set-UMServer Server1.companyabc.com -SipAccessService EdgePool.companyabc.com:5062