Technical data

534 Chapter 18
T1 Analyzer
More Information About T1 Testing
T1 Analyzer
The receive signal is often much weaker that the transmit signal. Cross talk in the
cable pairs can cause the transmit signal to appear on the receive pair and interfere
with the low-level receive signal.
Frame:
Pulses streaming in a T1 circuit would be meaningless if there was no way to
organize them in a meaningful structure. In T1, bits are organized into 192 bit
frames with an associated single frame bit for a total of 193 bits. The frame bit
pattern has unique characteristics that allow the receiving end to recognize it and to
synchronize to it. D3/D4 framing patterns have the ability to identify a super frame
of 12 sub-frames. Extended Super Fame (ESF) has the ability to identify a super
frame of 24 sub-frames and include a data link channel and Cyclic Redundancy
Checksum (CRC) check bits.