Installation guide

3.3 Call Flow
Inbound Call Flow:
1. A PSTN phone originates a call to an AT&T IP Flexible Reach service number.
2. The PSTN routes the call to the AT&T IP Flexible Reach service network.
3. The AT&T IP Flexible Reach service routes the call to Synapse System at Customer Site.
4. Synapse System applies any necessary digit manipulations based upon the DID and
routes the call to a hunt group, phone or a fax endpoint.
Outbound Call Flow:
1. Synapse System phone or fax endpoint originates a call for delivery to AT&T IP Flexible
Reach service network.
2. Synapse System applies any necessary origination treatment (verifying permissions,
determining the proper route, selecting the outgoing trunk, etc.) and routes the call to
AT&T IP Flexible Reach service network.
3. The AT&T IP Flexible Reach service network delivers the call to PSTN.
4. PSTN delivers the call to a phone or fax endpoint.
Deskset-to-Deskset Call Flow:
 A Synapse Deskset originates a call to a 2nd Deskset by using an extension number.
The call is routed based on internal signalling within the Synapse System. This does
not occupy any trunk.
 A Synapse Deskset originates a call to a 2nd Deskset by dialing a 10/11-digit
telephone number. The call is routed through the Outbound Call Flow (described
above) and the Inbound Call Flow (described above) and then reaches the 2nd
Deskset based upon DID. This occupies two trunks for the whole duration of the call.
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