Call processing functionality in SLS mode

Last Updated : Apr 28, 2023 |

In survivable mode, SLS provides only a limited subset of CM call processing functionality:

  • Limited call routing through a Survivable ARS Analysis Table (through the CLI) and COR calling permissions

  • Inbound calls are directed in one of three ways:

    • Using the Incoming-Routing screen

    • Using the Set Incoming-Destination on the Trunk group screen that enables mapping to a given station

    • Inbound calls are directed to a previously-administered pool of available stations (the Survivable Trunk Dest? field is y on the Station screen). The search algorithm is circular so that the incoming calls are fairly distributed.

      Important:

      SLS permits 911 calls, but the specific location information is not transmitted to the Public Service Answering Point (PSAP). Only the general trunk-identifying information is transmitted. Emergency personnel will have a general location associated with the trunk (for example, a building address), but nothing more specific (for example, a room or office number). Also, if a 911 call disconnects for any reason, emergency personnel cannot reliably call the originator back. A small business office’s address is sufficient from the perspective of emergency routing.

  • CM Feature Access Codes for ARS, contact closure, and Hold

  • Acts as an H.323 Gatekeeper that enables IP endpoints to register simultaneously

  • Direct Inward Dialing

  • Multiple call appearances

  • Hold and Call Transfer functions

  • Contact closure feature

  • Call Detail Recording (CDR)

  • Trunk Access Code (TAC) dialing

  • Non-ISDN DS1 trunks (with in-band signaling)

  • ISDN PRI/BRI trunks:

    • T1 robbed-bit All 24 channels serve as trunks without full 64 kbps transmission

    • E1 CAS All 31 channels serve as trunks with full 64 kbps transmission