Yes.
>this relate to channelized/unchannelized T1 circuits ? I want to know
They are related in that PRI (in the US) is based on T1 technology.
You could think of it as cutting a T1 into 24 pieces (1 is the D channel)
and using ISDN signalling.
It is similar to, but certainly not the same as, channelized T1.
With channelized T1 you get 24 56K data channels. This means no ISDN of
course. The channels are smaller because instead of doing all the
singalling on one channel like PRI (which is why you get 23 bearer
channels and 1 data channel) the signalling is done on each channel
individually - with 8K being devoted to that.
(I understand that channelized E1 gives 30 64K lines because 2 lines
are reserved for signalling - and E1 PRI is 30 B channels with 1 D
channel, and 1 channel for another type of signalling. I readily
admit to being fuzzier when it comes to non-US standards.)
-MZ
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