Multi-Site Inbound Redundancy Using DNIS

In a multi-site environment, the Vocera Voice Server uses the Dialed Number Identification Service (DNIS) to determine which site's hunt group number was called and thus which site grammars to use for the call. With additional PBX configuration or utilizing Advanced Routing Features possibly offered by your Central Office, your inbound calls can be routed automatically to the PBX at a different site when one of your telephony servers goes down.

Important: This feature is available only if the target (ending) telephony server uses ISDN or SIP signaling protocol.

The following figure illustrates multi-site inbound redundancy using DNIS:

Figure 1. Multiple site inbound redundancy
  1. Someone places a call to a badge user at Site A.

  2. The Central Office routes the call to Site A based on the called number.

  3. The VSTG at Site A is down, so the call is routed back to the Central Office.

  4. The Central Office routes the call to another PBX at a different site using an alternate routing plan.

  5. The call is received by the Vocera Voice Server, which knows which site grammars to use based on the dialed number.

  6. The badge user at Site A receives the call.

If a call made to a site is rejected by the initial PBX for any reason (for example, the VSTG may not be responding), the call can be routed by the Central Office to another PBX at a different site using an alternate routing plan. When the call arrives at the telephony server at the other site, it sends the call to the Vocera Voice Server. The Vocera Voice Server knows which site grammars to use based on the dialed number.