Branch Gateway survivability

Last Updated : Oct 17, 2023 |

Branch Gateway provides the following configuration options for continuous phone services:

  • You can configure Branch Gateway to use up to four MGCs. Each controller can be configured with an IPv4 and IPv6 address. Each configured address is either an IPv4 address of a TN799 (C-LAN) board connected to the server or an IPv4/IPv6 address of the Communication Manager Processor Ethernet interface. The four addresses are grouped into primary and secondary controllers, using a transition point to separate the two groups.

  • Using connection-preserving migration, you can configure Branch Gateway to preserve the bearer paths of stable calls if Branch Gateway migrates to another MGC, including a Local Survivable processor (LSP) also known as Survivable Remote Server (SRS). This also applies to migration back from an LSP to the primary MGC. A call with an established audio path between all parties is considered stable. A call with a one-way audio path is not considered stable and therefore is not preserved. Any change of state leads to ending the call. For example, putting a call on hold during the MGC migration ends the call. Special features, such as conference and transfer, are not available on preserved calls. Connection-preserving migration preserves all types of bearer connections except BRI. PRI trunk connections are preserved.

  • You can configure Standard Local Survivability (SLS) to enable a local Branch Gateway to provide a limited MGC functionality when there is not connection to an external MGC. You can also configure SLS from Branch Gateway using a Command Line Interface (CLI). SLS is supported for all analog interfaces, ISDN BRI/PRI trunk interfaces, non-ISDN digital DS1 trunk interfaces (T1 Robbed Bit and E1-CAS), IP phones, IP softphones, and DCP phones. SLS is available only in IPv4.

  • You can configure Enhanced Local Survivability (ELS) by installing S8300 in Branch Gateway as a Local Survivable processor (LSP) also known as Survivable Remote Server (SRS). In this configuration, S8300 Server is not a primary MGC but takes over to provide continuous phone services if all external MGCs become unavailable. Active calls continue without interruption when S8300 Server takes over.

  • You can configure the dialer interface to connect to Branch Gateway primary MGC by a USB modem if the connection between Branch Gateway and the MGC is lost.

  • You can configure Avaya Aura® Communication Manager to support the Auto Fallback feature. A LSP enables Branch Gateway to return to the primary MGC automatically when the connection is restored between Branch Gateway and the MGC. When a LSP services Branch Gateway, it automatically attempts to register with the MGC at periodic intervals. The MGC can deny registration if it is overloaded with call processing or in other configured conditions. By migrating Branch Gateway to the MGC automatically, a fragmented network can be unified more quickly, without manual configuration.

    Auto Fallback does not include survivability. Therefore, there is a short period during the registration with MGC, during which calls are dropped and the service is not available. This problem can be minimized using connection-preserving migration.

  • With a dynamic trap manager you can ensure that Branch Gateway sends traps directly to a currently active MGC. If the MGC fails, the dynamic trap manager ensures that traps are sent to a backup MGC.