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POTS question

J

joseph2k

Jan 1, 1970
0
Don said:
What has all this to do with POTS and a DS0?

Don

Just what i have been trying to tell you, since sometime in the 1960's POTS
lines are converted to DS-0 using 56 k-samples/second CVSD's. The
oversampling moves the noise "out of band" big time and the analog filters
are much easier to implement.
 
D

Don Bowey

Jan 1, 1970
0
Just what i have been trying to tell you, since sometime in the 1960's POTS
lines are converted to DS-0 using 56 k-samples/second CVSD's. The
oversampling moves the noise "out of band" big time and the analog filters
are much easier to implement.

You don't know what you are talking about. Do some homework.

Don
 
joseph2k said:
Gegen dummheit kampfen die Gotter Selbst, vergebens.  
--Schiller

That's rather imprecise.

Schiller's original words: "Mit der Dummheit kämpfen Götter selbst
vergebens" (Die Jungfrau von Orleans, III, 6). These days it is commonly
rendered as "Gegen Dummheit ...". In ASCII, use "ae" for "ä" and "oe"
for "ö".

Anno
 
D

David Lesher

Jan 1, 1970
0
The last time I worked with T1s, no data bits were stolen for signaling
at all. The frame bits (bit 193 of a 24 channel frame) are not all
required for framing and now most of those are used for overhead
channel signalling. As of 2001, we used the 4th, 6th or 8th frame bits
(depending on configuration) for actual framing, leaving the others
available for control signalling.



The stolen bits are at the DS0 level; not the DS1. And they happen
with "CT1" aka 24 B channels on a DS1. It's a carryover from E&M
signalling, itself invented about the time of that squabble with
the Spanish Armada.

Now, PRI is more common than CT1; it has twenty three 64Kbps
B channels and a separate 64Kbps D (signalling) channel.
 
D

Don Bowey

Jan 1, 1970
0
I believe you are speaking of the ESF data link. In the public telephone
network, it is not used for "overhead channel signaling." It is used for
continuously transmitting performance report messages, when activated.
The stolen bits are at the DS0 level; not the DS1. And they happen
with "CT1" aka 24 B channels on a DS1. It's a carryover from E&M
signalling, itself invented about the time of that squabble with
the Spanish Armada.

Now, PRI is more common than CT1; it has twenty three 64Kbps
B channels and a separate 64Kbps D (signalling) channel.

PRI (23B + D) is *not* at all common except, perhaps, in private networks.

The POTS network has been transitioning from robbed bit signaling to Common
Channel Inter-office Signaling, CCIS for many years. Last I heard,
Signaling System 7 handled the CCIS functions, CCIS uses *none* of the bits
of the channels nor their parent DS1. In fact, bandwidth for a call is not
assigned until CCIS has determined that the call has a high degree of
potential for completion.

Don
 
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