All the numbers indicated 2B+1D, 23B+1D and 30B + 1D are all properl. And for B and D channels in PRI (T1 and E1) is 64 kbps.
So when you sum it up, the bandwidth is only 1536 for T1. Where is the other 8 kbps (True T1 is 1544kbps and not 1522kbps). 1536 kbps is the payload bandwidth. 8kbps is used for framing and synchronization.
A base T1 frame has 193 bits, 24 time slots. The first bit of each frame forms the synchronization channel which creates the 8 kbps channel.
A E1 frame has 256 bits, 32 time slots and one 64 bit channel is dedicated for frame synchronization, alarms etc just like the 8 kbps channel for T1. Another 64 kbps channel is used for signalling (the D channel of E1) and the rest 30 channels are used for payload (each 64kbps).
This document gives several answers on frequently asked questions for PFRv3 channel state behavior.
Q1: What are all the channel operational states from a BR (border role) perspective and what are the rules/conditions to be in each st...
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