IP Trunk 3.01 (and later) and CS 1000S/CS 1000M 25CS 1000M do not require a Gatekeeper Request from IP Trunk 3.01(and later); therefore, no Request or Confirm is sent.2. Gatekeeper Confirm (GCF) – From the Gatekeeper to the ActiveLeader, with the functional Gatekeeper IP address. This address is usedfor all call control messaging and registration messages between the IPTrunk 3.01 (and later) cards and the Gatekeeper.3. Gatekeeper Registration Request (RRQ) – From the Active Leader tothe Gatekeeper, with all of the node’s IP addresses.IP addresses are only sent if required. A CS 1000M does not require allIP addresses, so the IP addresses are not sent.4. Gatekeeper Register Confirm (RCF) – From the Gatekeeper to theActive Leader, providing the TTL prior to a re-registration attempt bythe leader and indicating under what conditions admission requestsare needed.Typically, the TTL is in minutes. The default IP Trunk 3.01 (and later)value, if no response from the Gatekeeper is received, is 300 seconds.However, the Gatekeeper can enforce a shorter interval in seconds ortens of seconds. The standards allow seconds from 1 to (232) –1.RecommendationNortel recommends that the TTL be provisioned in the 30- to 60-secondrange.The IP Trunk 3.01 (and later) node must perform a "keep-alive"re-registration prior to the expiry of the timer on the Gatekeeper. Whenthe Gatekeeper timer expires, a full registration is needed.IP Trunk 3.01 (and later) and CS 1000S/CS 1000MThe CS 1000M systems use virtual trunking (IP Peer Networking) tointer-operate with the IP Trunk 3.01 (and later) nodes. However, the CS1000M can be a Gatekeeper for the system.When IP Trunk 3.01 (and later) is part of a network with a Signaling Serveracting as a central control point, it is able to take partial advantage of afeature known as IP Peer Networking. IP Peer Networking eliminates themultiple conversions between IP and non-IP circuits, increasing call routingefficiency and overall voice quality. Many calls involving an IP Peer endpointand one or more IP Trunk endpoints can use this capability. However, callsthat use only IP Trunk facilities, and a small subset of calls involving bothIP Trunk and IP Peer, cannot obtain this benefit.IP Trunk 3.01 (and later) supports Gatekeeper Registration and AdmissionSignaling (RAS) and Call Admission Signaling. IP Trunk 3.01 (and later)interworks with CS 1000M, which fulfills the role of a Gatekeeper. UsingNortel Communication Server 1000IP Trunk FundamentalsNN43001-563 02.01 StandardRelease 5.5 21 December 2007Copyright © 2007, Nortel Networks.
