2.7 ST Connecting Options
Direct PSTN Connection
Advantages and disadvantages
This is the most reliable and simplest connecting option. The costs include acquisition costs plus a line installation fee, yet the ST operation is relatively cheap (monthly fee).
Cautions
- The line must be dedicated to ST only, serving no other devices.
- The line may not be serial or group line.
Notes
- You are not recommended to use the telephone set offered for lease while arranging the line.
- The telephone socket and associated cabling are the network provider's property and may not be tampered with.
- Report the ST installation and submit compliance certification upon request.
- Your follow-up cabling must be in conformity with the relevant safety regulations.
- You are recommended to secure your line against piracy,e. g. use a telephone lock.
GSM Gateway Connection
Advantages and disadvantages
This is a rather costly solution for places where no telephone line is available.
Cautions
- Back up the GSM gateway reliably in case of power outage.
- With a pre-paid SIM card, ensure credit monitoring and on-time charging.
Tips
- Verify the signal coverage and intensity in the place before selecting your GSM provider.
- Choose the optimum location for your antenna.
- Use an external directional antenna for places with a bad signal quality.
- Ensure that your GSM gateway function will go on working upon power failure without the need to enter the PIN.
- Safeguard the GSM gateway SIM card against misappropriation.
PBX Connection
Advantages and disadvantages
This is the cheapest connecting option wherever a PBX and an unoccupied PBX line are available. Where the ST is connected to a non-stop well-trained service personnel only, its operation costs are zero.
Caution
- Make sure that your PBX is protected against power outage. In the event of power outage, non-backed-up PBXs switch over some of their lines directly to CO lines and, in that case, the ST may call another subscriber if a prefix is used! For a smart solution see the Tips below.
For the ST to call outside the building (i.e. via PSTN):
- The line to be used must have the relevant call barring status (use a common telephone and try to call "outside" for check)
- While programming, add prefixes for PSTN seizure (typically a zero), or select a direct PSTN line seizure.
- To enable dispatcher center – ST calling, identify the line (extension) to be used and how to reach it from the outside (dial-in, DISA, operator), and select the appropriate PBX configuration (allowing to call the ST even in the night without an operator).
- Select the appropriate call barring status for the extension to be used if any of the pre-programmed numbers is a mobile (GSM) one.
- Agree with the PBX owner on operation costs (ST outgoing calls are at the owner's account).
Tips
- The operational costs can be solved by the "green line" (prefix 0800) calls.
- The so-called automatic CO line seizure (without dial-in) is a practical solution, which, in the case of ST switchover to a PSTN line due to power outage, makes the ST always call the right number.