- 67 -List of termsNortel Multiservice Switch 7400/15000/20000TerminologyNN10600-005 7.2S1 StandardPCR7.2 and up March 2006Copyright © 2006, Nortel Nortel ConfidentialInternet control message protocol (ICMP)A collection of error conditions and control messages exchanged by IPmodules in both hosts and gateways. Examples consist of echo requests andreplies and notification of discarded datagrams.Internet group management protocol (IGMP)A protocol that is used between routers and locally attached hosts tocommunicate multicast group membership information.Internet protocol (IP)A protocol suite that operates within the Internet as defined by the requestsfor comment (RFC). This term can also refer to the network-layer (level 3) ofthis protocol stack-the layer concerned with routing datagrams from networkto network.Internet protocol interface over frame relay (IPIFR)Allows a Nortel Multiservice Data Manager workstation to communicate withNortel Multiservice Switch nodes over frame relay. Once the connectionbetween a workstation and a node has been established, Multiservice DataManager can connect to the node over frame relay and exchange IPdatagrams.Internet protocol interface over virtual circuit (IPIVC)In Nortel Multiservice Switch device’s initial releases, FTP, Telnet, Ssh, andFMIP protocols are implemented over TCP/IP protocols using the IPIVCsystem. This system allows Nortel Multiservice Data Manager workstations tocommunicate with Multiservice Switch nodes by way of X.25 on DPN-100.Once the connection between a workstation and a DPN-100 module has beenestablished, Multiservice Data Manager can connect to the node over theX.25 virtual circuit and exchange IP datagrams. The ftp connections can beeither secure or non-secure as described in the Multiservice Data ManagerSecurity User Guide.inter-region Multiservice Switch trunkA Nortel Multiservice Switch trunk that is a link between two border nodes indifferent topology regions.interrupting modeSee frame-cell trunk (page 54).intra-domain linkA PNNI link that connects two nodes that are in the same local reroutingdomain.