Find the attenuation in dB of a 22 gauge UTP for 100 KHz at

Find the attenuation [in dB] of a 22 gauge UTP for 100 KHz at 14 Km Your HDLC control bits are 11001110. What can you say about this?

Solution

A)

attn = 4.62 dB/km * 14 km
= 64.68 dB

b)

The first 2 bits in control byte sequence 11 prove that the frame in which the byte sequence is present is a Unnumbered frame
3 and 4 bits form one code part
6 7 8 bits form other code sequence
5th bit is P/F bit
Poll/Final and is used for these two purposes. It has, meaning only when it is set i.e. when P/F=1. two cases.

(i) It means poll when frame is sent by a primary station to secondary (when address field contains the address of receiver).

(ii) It means final when frame is sent by secondary to primary