AT&T Synapse Installation Manual page 16

If you install one SB67010 PSTN Gateway or SB67060 T1 Gateway and then one Deskset, the feedback described in this guide
matches what you see on your system devices.
A system must have at least one PSTN Gateway or one T1 Gateway. There can be up to four PSTN Gateways, and a system can
include both a T1 Gateway and PSTN Gateways. Figure 7 illustrates the minimum components needed to make the system work
(blue line = telephone; red
The system uses a Local Area Network (LAN) for system communication. It uses Public Switched Telephone Network
(PSTN) connections for outside calls.
Deskset
Figure 7. Simplified System (PSTN Gateway and SB67030 Deskset Shown)
Installation
Synapse Installation Guide
lines = Ethernet).
Local Area Network (LAN) Gateway
15
PSTN Plug