This read-only enumeration classifies calls handled by the Clarent Gatekeeper by the combination of endpoint types involved, distinguishing pure H.323-to-H.323 calls, H.323-to-Clarent calls, unsuccessfully routed H.323 calls, and the various Clarent-to-Clarent or Clarent-to-H.323 combinations, plus a total category covering all of them. It's the classification key that the related counters gkNumberOfCalls, gkCallTime, gkAverageHoldTime, and gkNumberOfConnectedCalls are broken out by, letting an admin see call volume by endpoint mix. For example, an admin comparing counters for clarent2h323(6) versus h323h323(3) can tell whether most gateway traffic is interoperating with third-party H.323 gear or staying within Clarent-to-Clarent calls.