Lync 2013 Failover 513 Message Too Large

I was troubleshooting outbound calling failures in a Lync 2013 environment.  When making an outbound call to the SBC, I found that the SBC was responding back with a 513 Message Too Large (https://tools.ietf.org/html/rfc3261#section-21.5.7) The server was unable to process the request since the message length exceeded its capabilities. Lync was not invoking the failover route for this particular error, luckly we are able to translate the 513 code to something that Lync would invoke failover for like a 503. New-CsSipResponseCodeTranslationRule -Parent "PstnGateway:192.168.0.240" -Name "Rule513" -ReceivedResponseCode 513 -TranslatedResponseCode 503 This was just a temporary fix until I was able to work with the SBC vendor to determine the root cause, which in this case turned out to adjust the size of messages sip-message-len parameter in the Acme Packet SBC.