A TCP socket that is a normal server port is currently in the ESTABLISHED state, and

receives a protocol$-$compliant valid TCP segment.

$($a$)$ For each of the following bits or bit ranges in the TCP header of this segment, state whether it

is possible to be certain what the value is$,$ what that value is$,$ and the reasoning behind it$.$ If it is

not possible to be certain of the value itself, then state whether the value is valid $($has

significance to the TCP kernel or the application$),$ or invalid $($the values have no significance and

will not be used by any code$)$ again with reasoning. $($Bit and byte numbering in the header

start with $0$ as always.$)$

$$ Bit $107$

$$ Bit $110$

$$ Bit $111$

$$ Bytes $01$

$$ Bytes $23$

$$ Bytes $47$

$$ Bytes $811$

$$ Bytes $1617$

$$ Bits $9699$

$($b$)$ What set of bits, if any, within the range Byte $0$ to Byte $19$ can we be sure are not valid, in

this segment?