Destination-Host  AVP ( 293 )

This AVP MUST be present in all unsolicited agent initiated messages, MAY be present in request messages, and MUST NOT be present in Answer messages. The absence of the Destination-Host AVP will cause a message to be sent to any Diameter server supporting the application within the realm specified in Destination-Realm AVP. This AVP SHOULD be placed as close to the Diameter header as possible.

Reference: RFC 6733   View