Programming a 3300 Analog Gateway

Configuration Considerations

A) Outgoing Trunk Call Routing (including E911)

With the 3300 Analog Gateway solution, hosted IP phones are registered on the 3300 ICP at the Head Office location. Automatic Route Selection (ARS) is programmed at the Head Office to ensure that outgoing external calls (especially E911 calls) for hosted phones are routed through IP trunking to the appropriate gateway. ARS route lists are used for this purpose. Since ARS is limited to six ARS routes in a single route list, and one route is assigned for local dialing, then this solution is limited to five 3300 Analog Gateways per 3300 ICP in the Head Office. If there are more than five Analog gateways, the solution is to configure a Virtual Loopback IP Trunk.

TIP: The use of this local trunk is for both external local calls and 911 purposes. In addition, if you have enough local trunks, you may route calls from Head office to these selected local trunks on these Analog Gateways to maximize the usage of system resources and to provide savings on long distance charges.

General Programming Guide
(for reference only. Actual implementation may vary from site to site)

NOTE: The following are general programming guidelines and are provided for reference only. Actual implementation may vary by site.

The purpose of these steps is to ensure that the hosted IP phones that reside at the same geographic location as the Analog Gateway will select the proper analog trunk for local and 911 calls (that is, the trunk attached to that same Analog Gateway).

  1. Set up an IP trunk between the 3300 ICP in the Head Office (the host PBX) and all remote Analog Gateway(s).

  2. On the host PBX, create a route for each Analog Gateway (A maximum of six routes: five routes for remotely situated Analog Gateways plus one local route, ensuring that each route uses a unique COR.)

    NOTE: The selection of route for the appropriate Analog Gateway is based on COR.

  3. Set up a route list that contains all routes created in step 2 (5 Analog Gateway routes + 1 local route).

  4. Program ARS leading digits for both local access and local 911 and assign the route list created in step 3.

    NOTE: It is critical that the proper COR is assigned to each route and the corresponding IP phones. The routing mechanism to the proper Analog Gateway location is based on the COR of the set and the COR group defined for each route at the host PBX.

  5. On each Analog Gateway, make sure that the ARS leading digits for both local and 911 are created and that the local analog trunk is selected to process local and 911 calls.

B) Incoming trunks calls, answer points and voice mail: Centralized Approach

In this approach, either the centralized Auto Attendant (AA) or the console at the Head Office should handle all Loop Start (LS) calls arriving at the Analog Gateway. It is recommended that hosted IP phones residing in the geographic area of the local Analog Gateway have a shared key/multi-line key as a common answer point. This serves as a fail-safe operator for each local site in the event that the call cannot present/reroute to the centralized AA/console. In this scenario, voice mailboxes for all phones will be at the Head Office location. Benefits include access to the entire corporate phone directory for dial by name. Sufficient bandwidth between sites needs to be engineered to accommodate incoming calls and voice mail access.

General Programming Guide
(for reference only. Actual implementation may vary from site to site)

  1. On each Analog Gateway with analog trunk, assign a local analog answer point in Day, Night1 and Night2 of the Trunk Attributes form.

  2. Set up Call Reroute First Alternatives to reroute the local analog answer point on no-answer conditions to the centralized attendant or to the console at the Head Office location.

    NOTE: To speed up call forwarding, set up a separate Class of Service (COS) for the analog answer point and reduce Call Forward No Answer to 1 or 2 seconds.

  3. Set up Call Reroute First/Second on Busy and DND Condition to a shared key/multi-line key which serves as a catch-all answer point in the event of Head Office failure.

    NOTE: If you do not use the local analog phone as an answer point, make sure that those IP phones sharing a common key fail over to the Analog Gateway in the event of a failure at the Head Office.

C) Incoming trunks calls, answer points and voice mail (VM): Distributed Approach

Since Analog Gateways support voice mail and auto attendant (AA) functionality, it is possible to distribute VM/AA to the gateways. Each gateway would be designated to provide voice mailboxes and auto attendant service to IP phones in its geographical region. (Referring to the above diagram, Analog Gateway 1 would support VM/AA services on phones that are LOCAL to Analog Gateway 1).

Each VM/AA setup is responsible for voice mail and auto attendant functions (including the dial-by-name feature) for those users in the region local to the corresponding Analog Gateway. For users served by AA in the Head Office (and other remote Analog Gateways), set up a menu node in the local AA to redirect any voice mail services to the corresponding VM/AA.

NOTES

 

General Programming Guide
(for reference only. Actual implementation may vary from site to site)

  1. Determine the number of mailboxes (n) required for each Analog Gateway. As a general guide, the number of mailboxes is equal to the number of IP phones in the local region. Add two more mailboxes ("0" and "9999") for administrative purposes. Purchase and activate the required mailboxes (minimum of n+2) for each corresponding Analog Gateway.

  2. Create VM pilot numbers for each Analog Gateway. We suggest that these numbers be clustered.

  3. In the Head office, program the Call Rerouting form ( ) for each individual VM pilot and then assigns the proper call rerouting index to each individual phone based on its physical location.

TIP: It is good practice to maintain the same call rerouting index (that is, the same answer point) between Head office and Analog Gateways.

  1. For the AA at the local Analog Gateway, VM pilot numbers should be assigned in the local trunk answer point (Trunk Attributes form ) so that the local AA will handle local calls.

  2. For each local AA, set up a menu node so that dial-by-name or other access to Head Office, or other remote Analog Gateway, will be sent to the proper location and served by the corresponding Auto Attendant.

NOTE: The dial-by-name feature can only be used for local users.

D) Considerations for Resiliency support

In the event of a Head Office failure or a failure in the network leading to the Head Office, IP Phones can be programmed to fail over to the selected gateways to maintain phone services.

The following is high level programming summary. For full feature implementation, please refer to the Resiliency Guidelines.

  1. Program a general cluster configuration between Head Office and the Analog Gateway(s).

  2. Based on the proximity of the IP phone and the location of the Analog Gateway, determine how many IP phones will provide failover for their corresponding gateways, and the configure these devices as resilient.

NOTES

 

 

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