Browse Prior Art Database

Dynamic Local Area Network Filter Algorithm

IP.com Disclosure Number: IPCOM000116794D
Original Publication Date: 1995-Nov-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Angst, DL: AUTHOR [+3]

Abstract

Certain Local Area Network (LAN) protocols generate lots of extra traffic on the LAN which must be discarded by workstations which do not wish to receive this traffic. The easiest method is allow the frames to be received by the Media Access Control (MAC) layer which send the frames to the Logical Link Control (LLC) layer. The LLC layer discards the frames because the proper protocol stack to process the frame is not installed. The processing power the LLC layer uses to ultimately throw away the frames is wasted.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 68% of the total text.

Dynamic Local Area Network Filter Algorithm

      Certain Local Area Network (LAN) protocols generate lots of
extra traffic on the LAN which must be discarded by workstations
which do not wish to receive this traffic.  The easiest method is
allow the frames to be received by the Media Access Control (MAC)
layer which send the frames to the Logical Link Control (LLC) layer.
The LLC layer discards the frames because the proper protocol stack
to process the frame is not installed.  The processing power the LLC
layer uses to ultimately throw away the frames is wasted.

      A better solution is to install a filter in the MAC layer which
automatically discards these frames at the MAC layer before they are
sent to the LLC layer to be discarded.  This saves processing power.
Consider the scenario where a protocol stack is installed above the
LLC layer to process these frames.  In this situation the filter must
be removed so the new protocol stack works properly.  Conversely,
when the protocol stack is not present, the filter should be present
to keep processig for these frames to a minimum.  This disclosure
gives a dynamic algorithm such that when the protocol stack installs
itself on the LLC layer the LLC layer sends a message to the MAC
layer to either disable or enable the filter.  This allows optimal
processing in both environments.  When the protocol stack is present,
the filter is removed and the frames flow normally.  When the
protocol stack is not present...