Avaya 1000 Installation And Commissioning Manual page 62

How the Branch Office feature works
Server. If no Alternate Call Server is available, the Branch Office IP Phones reset and reregister with
the MG 1000B in Local Mode.
The user has the option of going to Local Mode manually by resetting the telephone or using Test
Local Mode. In Local Mode, the IP Phones can make local calls to other IP Phone and analog
(500/2500) or digital phones at the Branch Office. They can also be used to make outgoing PSTN
calls and receive incoming calls as usual.
Important:
When a telephone or trunk in the Main Office calls an MG 1000B IP Phone in Local Mode, the
call is treated according to the Main Office call redirection configuration (such as forwarding to
voicemail or continuous ringback).
When an IP Phone at the Branch Office first boots up it attempts to communicate with the MG
1000B. Once it has established communications with the MG 1000B, the MG 1000B will redirect the
IP Phone to the main office.
Before the Branch Office IP Phone attempts to register with the main office, the MG 1000B first
queries the Primary NRS (NCS) fro the main office for the Virtual Trunk node IP address to redirect
the IP Phone. If the Primary NRS (NCS) is down or unreachable, the MG 1000B queries the
Alternate NRS, if one is specified. If it receives a positive response, the MG 1000B is redirected to
the specified main office. Otherwise, it neither a Primary or an Alternate NRS is available, the
Branch Office IP Phone remains in Local Mode, and receives call processing services from the MG
1000B until communication is reestablished.
If an IP Phone is in Local Mode due to WAN failure, the MG 1000B tries to communicate with the
main office TPS at regular intervals. Once communication is established with the main office Call
Server, the idle Branch Office IP Phones are automatically redirected and reregistered to the main
office. IP Phones that were busy at the time communication was reestablished, complete the call in
Local Mode, and then reregister with the main office once the call is complete.
MG 1000 IP Phones in Normal Mode remain registered with the main office if the Primary NRS fails
and no Alternate NRS is available. They can call any main office telephone or IP Phones in Normal
Mode in other branch offices. However, they cannot call an Branch Office analog (500/2500-type)
telephones, digital telephones, or any external numbers through the MG 1000B trunks because the
Virtual Trunks are not available. (MG 1000B analog [500/2500-type] or digital telephones, are
accessible if alternate routing is available through the PSTN.)
Features supported in Local Mode
In Local Mode, IP Phones receive only those features and tones that are provisioned on the call
server. The features are not necessarily the same in Normal Mode due to local configuration, or if
the Branch Office and main office are running different software releases or different service levels.
When the Branch Office is running a previous software release, the Local Mode features are limited
to those available in that release. Depending on what is provisioned, this means that Normal Mode
may have more features than Local Mode.
A user can attempt a Virtual Office Login to an MG 1000B IP Phone from an MG 1000B IP Phone in
Local Mode. If the Virtual Office Login is successful, the Virtual Office user is registered with either
the Branch Office or main office. A Branch Office in local mode only accepts Coordinated Dialing
Plan (CDP) numbers as Virtual Office user ID's.
Branch Office Installation and Commissioning
62
Comments? infodev@avaya.com
June 2014