Both actually. Keeps the PBX from placing a call at the exact same time the central office is sending a call. (glare). PBX grounds the ring side of the line to indicate it wants dial tone. The central office reciprocates by a ground on the tip side of the line. The PBX then goes off hook and everybody lifts their grounds.
In reverse the C.O. grounds before ringing the line. Just a layer of handshake protocol to prevent glare. From: Adam Moffett Sent: Monday, November 27, 2017 12:22 PM To: [email protected] Subject: Re: [AFMUG] ATA CallerID question I've probably got that wrong, I think the PBX was expecting a pin to get grounded and since that didn't happen it would never pick up. In any case, I'm pretty sure it would ring but you couldn't answer it. ------ Original Message ------ From: "Adam Moffett" <[email protected]> To: [email protected] Sent: 11/27/2017 2:19:02 PM Subject: Re: [AFMUG] ATA CallerID question When I plugged loop start lines into a ground start PBX they couldn't answer the phones. I may not be remembering this right, but I think they did ring. I think the PBX would try to ground the line when you picked up a handset, and that resulted in a hangup on the ATA. That's also the incident which introduced me to the Adtran Total Access. It was the first ATA I found which supported ground start, and I've been very happy with that product. ------ Original Message ------ From: "Chuck McCown" <[email protected]> To: [email protected] Sent: 11/27/2017 11:47:26 AM Subject: Re: [AFMUG] ATA CallerID question Any chance of a ground start vs loop start issue? Some PBXs were ground start. Not sure how that would affect caller ID. Is the PBX actually detecting the ringing? From: Nate Burke Sent: Monday, November 27, 2017 9:34 AM To: [email protected] Subject: Re: [AFMUG] ATA CallerID question Just an Update, I put a splitter in the phone line, and caller ID works perfect on any 'modern' handset. But still does not work on the Lucent PBX. The customer still swears it worked with his old AT&T lines, but seems resigned to the fact that he won't have caller ID Anymore. I tried to sell him into a new PBX, but he "Has a truckload of spare parts for this PBX" On 11/9/2017 3:53 PM, Adam Moffett wrote: Oh right....I haven't picked up the phone yet so there's nothing to hear. Sorry. I haven't actually used one of these telephone thingys in a long time. ------ Original Message ------ From: "Lewis Bergman" <[email protected]> To: [email protected] Sent: 11/9/2017 4:52:46 PM Subject: Re: [AFMUG] ATA CallerID question Remember, the signal comes between rings. Unless you are listening on a butt set in line or watching the info pass through a switch you wouldn't see or hear it. The only reason I remembered between first and second is sitting at a class 5 switch trying to figure out why caller ID was failing on a feature group D trunk group and seeing them come through after one ringy dingy. On Thu, Nov 9, 2017 at 3:46 PM Adam Moffett <[email protected]> wrote: Is it at an inaudible frequency? If so, then it wouldn't make it through 2600hz bandpass filters would it? Or maybe it's audible, but so short you don't notice it? I'm fuzzy on this. I probably shouldn't ask. I don't need to know that much about POTS anymore. ------ Original Message ------ From: "Lewis Bergman" <[email protected]> To: [email protected] Sent: 11/9/2017 4:40:57 PM Subject: Re: [AFMUG] ATA CallerID question More info than anyone probably wants to know. I found this about the original question: Caller-ID Signaling According to Telcordia specifications, CND signaling starts as early as 300 mS after the first ring burst and ends at least 475 mS before the second ring burst From here: http://www.tech-faq.com/caller-id.html On Tue, Nov 7, 2017 at 9:29 PM Adam Moffett <[email protected]> wrote: I did not know that tone contained modulated data. I just thought it was a noise you wouldn't ignore. That's a fun fact to have. ------ Original Message ------ From: [email protected] To: [email protected] Sent: 11/7/2017 4:39:27 PM Subject: Re: [AFMUG] ATA CallerID question >Monitor the line for the data burst. It is the exact same modulation >method as the emergency alert system you hear squawking on the TV >before the beep and thunderstorm warning. > >I think it comes before the first ring or right after the first ring. >Some of the original display units rectified and stored ring voltage >for power so it may need the ring first to power the display box then >the data. > >In any event, you can hear it if you have a butt sett with line monitor >mode. >Bell 202 is correct. > >-----Original Message----- From: Nate Burke >Sent: Tuesday, November 7, 2017 1:58 PM >To: Animal Farm >Subject: [AFMUG] ATA CallerID question > >At a customer, I just hooked up a Cisco SPA122 into an Ancient Lucent >PBX system. The customer says that caller ID is not coming through, >but >it used to work with his old AT&T Lines, and it appears to be hitting >the ATA Properly. Is there a setting on the ATA that needs to be set >that older systems may be looking for? > >The only settings I see for Caller ID in the ATA are Caller ID Method, >currently set to 'Bellcore(N.Amer,China)' and Caller ID FSK Standard, >set to 'Bell 202' I've never had to mess with those settings before. > >Nate
