Systems and methods are described for creating and managing Global Session Identifiers (GSIDs) for communication sessions. GSIDs provide a way to globally identify communication sessions including those communication sessions that have experienced one or more topology changes. The GSID may be considered a header itself or a value within a header and information contained within a GSID can be used to trace backwards through time to find the session segments that led up to (or exist concurrently to) a currently signaled session.