User's Manual

Centralized phone B5800 Branch Gateway B5800 Branch Gateway trunk (e.g. FXO, ISDN,
SP SIP trunk) PSTN
4. Centralized phone to headquarters or other enterprise site
B5800 Branch Gateway can be administered to send such calls over the PSTN. See below.
Calls to Centralized phones in survivability mode (aka rainy day)
1. From PSTN to centralized phone’s DID
PSTN
B5800 Branch Gateway trunk (e.g. FXO, ISDN, SP SIP trunk) B5800 Branch
Gateway centralized phone
Note:
In rainy-day the centralized phones register to survivability service on B5800 Branch
Gateway in the branch.
2. From PSTN to centralized phone via B5800 Branch Gateway auto-attendant
PSTN
B5800 Branch Gateway trunk (e.g. FXO, ISDN, SP SIP trunk) B5800 Branch
Gateway auto-attendant caller enters extension number centralized phone
3. From branch local phone to centralized phone (dialing either local phone’s enterprise number
or short extension)
Local phone
B5800 Branch Gateway centralized phone
B5800 Branch Gateway call flows
312 Implementing the Avaya B5800 Branch Gateway November 2011
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