Ref: 03250429
Title: IB Sequence Control vs. Line Filtering
Date: 5/19/88

Copyright 3Com Corporation, 1991.  All rights reserved.

QUESTION:  Please explain the difference between sequence control
and line filtering.

ANSWER: Sequence control is NOT line filtering.  In sequence
control, when there are multiple paths between networks, a mask
can be set up such that, if conditions are met, it will send
qualifying packets down the fastest line available. If all lines
are the same speed, selection will be based on the path number.

Since most protocols do acks, the mask has to be set up on both
IBs.

The confusion between sequence control and line filtering comes
about because the sequence control masks look like filters--with
the same rules and features.  However, sequence control, unlike
simple line filtering, provides the additional feature of
automatic backup--if the line that is normally used is
unavailable, it will apply the same criteria to selecting an
alternate line from those that are still available.
