Assume that you deploy an Edge server in a Microsoft Lync Server 2010 environment. Then, you set the Domain Name System (DNS) Service (SRV) record for federation (_sipfederationtls._tcp.EnvironmentDomainName) of the Edge server to an internal FQDN. When the server looks for an external route, the Rtcsrv.exe process on the Edge server crashes. Additionally, you receive the following error code:
This issue occurs because of an inconsistent state in the SIP stack Access Proxy routing engine.
To resolve this issue, install the following cumulative update:
2701585 Description of the cumulative update for Lync Server 2010: June 2012