ISDN Protocol Administrator's and Developer's Guide ... - Intervoice

T1 Transfer MethodsRelease Link TrunkThe Release Link Trunk (RLT) call transfer is a supplemental featurethat works with Nortel DMS-100 and DMS-250 switches running ISDNPrimary Rate Interfaces (PRI) on T1 trunk groups.For more information onthe DMS ISDN protocol,refer to “DMS ISDNProtocol,” Chapter 11.RLT is a method of call transfer that accepts calls on two differentBearer Channels (B Channels), pulls the two calls back from the OmviaMedia Server, then bridges them at the switch. It releases both Bchannels for further inbound or outbound calls. The initial calls cantravel on the same or different PRI trunk groups, but if the B channelsare on different PRI trunk groups, they must connect to the same DMSswitch.Both the primary and secondary trunks must be configured for the RLTfeature. If an outbound call from the Omvia Media Server is redirectedto a third-party number, then that number must also be configured forRLT. If the third-party number is not configured for RLT, the switchcannot return a Call ID to the Omvia Media Server, and the call transferdoes not occur.The characteristics of RLT are shown in Table 3-2.Table 3-2. Release Link Trunk (RLT) CharacteristicsSpan Type Transfer Type connect UserDLL?T1 Two Line Transfer Yes60001262, First Edition Call Transfer 3-3