HDLC-(ABM)-Addressing, Poll-Final-Bit, doubts about ISO/IEC4335 example
I have some doubts about the example of ABM information exchange with use of
RNR in ISO4335 chapter B.9.1.4. The standard states a frame with poll bit
set should be answered at the next possible opportunity with a frame where
the F-bit is set.
In my interpretation, the P/F-bit is interpreted as "P" if the frame
contains the address of the receiver. If the frame contains the address of
the sender, the P/F-bit is interpreted as "F".
Am I right there?
Now my doubts concerning example B.9.1.4 "ABM information exchange - Use of
B sends "B,I2,1F", then "A,RR1,P" - which is answered with "B,I1,3P". In my
opinion, the "B,I1,3A" starts after A has received "A,RR1,P" and must
therefore be "A,I1,3F" because the Poll-Bit must be answered first. Could
somebody explain me, why the "B,I1,3A" frame is sent instead?