PBX Must Use “Loop Start” (not “Ground Start”) Interface for GSP-2900 and FAU200
The Globalstar fixed phones, GSP-2900 and FAU200, provide a standard POTS (Plain Old Telephone Service) interface which can be used as an outgoing “TRUNK” line for a PBX. There are two standardized signaling methods which are used by PBXs to manage a POTS trunk line — “Loop Start” and “Ground Start”.
- Loop Start supervision is a supervisory signal from an end terminal to a switch in response to completing the loop path
- Ground Start is a signaling method from a terminal to a switch where one side of a cable pair is temporarily grounded
Requirements for PBX Configuration and Compatibility:.
- In order to use a Globalstar fixed phone as an analog trunk line on a PBX, the Globalstar tip/ring line must be connected to an analog FXO Loop Start voice port on the PBX.
- This is because the Globalstar “fixed phone” products, GSP-2900 and FAU200, only support Loop Start.
Globalstar Fixed Phone Features to Support PBX:
Loop Start and Ground Start
- The Globalstar GSP-2900 and FAU200 fixed phones detect Loop Start in accordance with BS 6305 and BS 6317.
- Ground Start is not supported
The GSP-2900 and FAU200 fixed phones provide the following signaling methods to support the PBX:
- Two-wire (tip/ring) Loop calling unguarded clearing protocol
- Loop Current Break (clear backwards)
- When a call is unsuccessful or cleared down by the far end, the fixed phone line interface delivers an appropriate tone (as determined by the network) followed by a break of the loop current.
- Called Subscriber Answer (CSA) indication using Line Reversal
- Immediate Ringing, used instead of ground start to reduce glare (call collision)
- Call collision events are handled in a manner that gives priority to outgoing phone calls
Keywords: Globalstar PBX compatibility GSP-2900 RAU GSP-2800 GSP-2400 FAU200 FAU-200