In my country payphone solutions for Call Shops are implemented using FXS SIP or H.323 gateways that implement the Polarity reversal feature that reverse polarity as soon as the other party answers. I have done this in several VoIP platforms but Asterisk.
Regular Payphones and Call Shop metering systems rely on polarity reversal for proper call billing implemented in a local table. Call Shop uses mainly a central billing unit (a PC or stand Alone) and serveral metering boxes with display that connects to the central unit by RS485 bus. These boxes connects to the lines (FXS on the gateways or special payphone lines provided by local carrier) and to normal phones. a Call Shop can have form 2 to 16 call boxes. It it good bussiness above 8. Billing systems are so simple electronically that they are manufactured here. Regards, Jorge A. -----Mensaje original----- De: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Enviado el: Mi�rcoles, 06 de Abril de 2005 11:01 a.m. Para: [email protected] Asunto: Re: [Asterisk-Users] how can i connect a cost display on asterisk <[EMAIL PROTECTED]> wrote: > Johannes, > I would be curious to know if there is a solution for this. Another > solution is that you buy a "call meter". Which is a small box that > can be placed in front of phone phone and that can display costs. > FXS--> call meter --> analog phone > This call meter needs to be programmed with a table inside and a > rate for each destination. It depends on the type of cost meter. One of BT's products is the Meter Pulsing Facility which sends a short 50Hz longitudinal tone on supervision, and just before a "unit" has been consumed. BT scrapped unit charging in the mid-90s but this particular bit of legacy remains. It's intended for payphones where you charge, say, 10p for a unit and want to know when the 10p has been consumed. That's why you can sometimes hear a buzz on a BT payphone a few seconds before the credit drops, because the longitudunal pulse sometimes breaks through into the audio path, even though shouldn't. I suspect this is because they payphone isn't properly earthed. A cost meter (or paypgone) that determines cost without exchange assistance will suffer from inaccurate pricing information and an inability to determine the start of supervision. Still, given that BT charge a hefty wedge for the MPF, some people just stick a COCOT on a standard exchange line and hope it's good enough that they don't get ripped off. -- Common sense is the collection of prejudices acquired by age 18. - Albert Einstein _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
