Window size negotiation
facility code format is:
43 0x 0y
Where x=max window size from called DTE to calling DTE
y=max window size from calling DTE to called DTE
coded from 1 to 7 (default 2)
Notes on window and packet size negotiation:
In Public Network these values are end-to-end, that is, no window or packet size conversion
is done by the network.
The receiving end may 'negotiate' a different value in the call accept packet
but it can only 'negotiate' toward the default.
see also