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CLID on T1 Module for ACS R6
- Thread starter dudeEWin
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Mostly because of telephony standards developed and accepted for use by common carriers and regulatory agencies in the world.
PRI uses a separate 64K channel to control flow and send information commands to the far end regarding data being transmitted on each of the 23 bearer channels. CLID and more is encoded in that stream which, being external to the channel, preserving its 64K bandwidth.
On a fractional T1, the control commands are embedded in the channel itself, where it "robs" 8K of space in the 64K bandwidth to create a control stream. By regulation, the 56K that is left has to remain intact; any additional data in the 8K control stream would lower the channel size and is prohibited by regulation.
To get around that, any additional data has to be external to or precede the stream. Externally, a seperate medium supporting a modem that transmits the extra data is known as SMDI. SMDI links are normally associated with Centrex and private voicemail and run $600-900 per month. To precede the stream means to slow the "set up" of the call by sending the information data first. Some telephone switch manufacturers sell "pseudo Centrex" services that allow for number-only or even name and number to be transmitted in the moments before the call is connected.
The key is that the CLID feature was developed and implemented as a digital bonus package overlaid on an analog line. When that digital bonus is laid on top of a digital network, that info can get lost in the many hand-offs if the equipment doesn't support the extra data. Much of the equipment in the "last mile" doesn't support the overlay because it doesn't have to by regulation. That equates to cheaper implementation and lower service fees. Competition has created an arena where proprietary equipment can do things not mandated by regulation for extra fees. That's where you have to determine the carrier of choice that has the features you need for yourself.
There's some speculation that some of the hybrid xDSL protocols in use in Europe may make their way here; some already have. Those allow for higher bandwidth at low cost, which translates into extra features for less. The problem has been that many of them don't work over extended distances; not a problem in France, but a big problem in Texas.
PRI uses a separate 64K channel to control flow and send information commands to the far end regarding data being transmitted on each of the 23 bearer channels. CLID and more is encoded in that stream which, being external to the channel, preserving its 64K bandwidth.
On a fractional T1, the control commands are embedded in the channel itself, where it "robs" 8K of space in the 64K bandwidth to create a control stream. By regulation, the 56K that is left has to remain intact; any additional data in the 8K control stream would lower the channel size and is prohibited by regulation.
To get around that, any additional data has to be external to or precede the stream. Externally, a seperate medium supporting a modem that transmits the extra data is known as SMDI. SMDI links are normally associated with Centrex and private voicemail and run $600-900 per month. To precede the stream means to slow the "set up" of the call by sending the information data first. Some telephone switch manufacturers sell "pseudo Centrex" services that allow for number-only or even name and number to be transmitted in the moments before the call is connected.
The key is that the CLID feature was developed and implemented as a digital bonus package overlaid on an analog line. When that digital bonus is laid on top of a digital network, that info can get lost in the many hand-offs if the equipment doesn't support the extra data. Much of the equipment in the "last mile" doesn't support the overlay because it doesn't have to by regulation. That equates to cheaper implementation and lower service fees. Competition has created an arena where proprietary equipment can do things not mandated by regulation for extra fees. That's where you have to determine the carrier of choice that has the features you need for yourself.
There's some speculation that some of the hybrid xDSL protocols in use in Europe may make their way here; some already have. Those allow for higher bandwidth at low cost, which translates into extra features for less. The problem has been that many of them don't work over extended distances; not a problem in France, but a big problem in Texas.
TouchToneTommy
Vendor
Gee, I was going to say because Rocks are Hard and Water is Wet and that's the way it is!
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