About On Demand Correlation
In the Mediation Engine Connection screen, when opening a call from an Mediation Engine node view, the Mediation Engine Connector tries to correlate the call against other calls seen in different Mediation Engines, then it is an On Demand Correlation.
- There is no real time in the inter-Mediation Engine call correlation.
- The Active Calls Mediation Engine Connector KPI is the sum of the active session from all Mediation Engines, there is no correlation behind and thus the value is higher than the real one.
The key for Mediation Engine Connector correlation is having the platform devices well defined across the Mediation Engines, assigning properly their internal/external role in the Platform Devices settings view. The call segment between an internal and an external device must be seen twice, by two Mediation Engines. There can be more than one segment between two Mediation Engines for the same call.
When a call leg happens between an internal and an external platform device, the Mediation Engine builds a hash that identifies that leg.
Call hash = hash ( INVITE message)
The Mediation Engine Connector relies on the call hashes to find the other related calls across different Mediation Engines. There is no hash between internal vs. internal or external vs external devices. Therefore, platform devices must be correctly configured or Mediation Engine Connector inter-node correlation does not occur. If two Mediation Engines don't see the same call segment the correlation is not possible. For correlation to occur, call segment must be seen twice.
- Find the related call's Mediation Engine:
- When opening a call from a node panel this step is not needed, since we already know the Mediation Engine node.
- When searching for calls from a regional panel, the Mediation Engine Connector queries all the Mediation Engines to find the related Mediation Engine(s).
- The ME where the call was found queries the neighboring nodes to check for additional call legs, using the call hashes. Furthermore, those nodes will check in another nodes, avoiding the nodes they already traversed.
