RFC 3662 (rfc3662) - Page 2 of 17

A Lower Effort Per-Domain Behavior (PDB) for Differentiated Services

RFC 3662                    Lower Effort PDB               December 2003


   considered as a network equivalent to a background priority for
   processes in an operating system.  There may or may not be memory
   (buffer) resources allocated for this type of traffic.

   Some networks carry traffic for which delivery is considered
   optional; that is, packets of this type of traffic ought to consume
   network resources only when no other traffic is present.
   Alternatively, the effect of this type of traffic on all other
   network traffic is strictly limited.  This is distinct from "best-
   effort" (BE) traffic since the network makes no commitment to deliver
   LE packets.  In contrast, BE traffic receives an implied "good faith"
   commitment of at least some available network resources.  This
   document proposes a Lower Effort Differentiated Services per-domain
   behavior (LE PDB) [RFC 3086] for handling this "optional" traffic in a
   differentiated services domain.

   There is no intrinsic reason to limit the applicability of the LE PDB
   to any particular application or type of traffic.  It is intended as
   an additional tool for administrators in engineering networks.

   Note: where not otherwise defined, terminology used in this document
   is defined as in [RFC 2474].

2.  Applicability

   A Lower Effort (LE) PDB is for sending extremely non-critical traffic
   across a DS domain or DS region.  There should be an expectation that
   packets of the LE PDB may be delayed or dropped when other traffic is
   present.  Use of the LE PDB might assist a network operator in moving
   certain kinds of traffic or users to off-peak times.  Alternatively,
   or in addition, packets can be designated for the LE PDB when the
   goal is to protect all other packet traffic from competition with the
   LE aggregate, while not completely banning LE traffic from the
   network.  An LE PDB should not be used for a customer's "normal
   internet" traffic, nor should packets be "downgraded" to the LE PDB
   for use as a substitute for dropping packets that ought to simply be
   dropped as unauthorized.  The LE PDB is expected to be applicable to
   networks that have some unused capacity at some times of day.

   This is a PDB that allows networks to protect themselves from
   selected types of traffic rather than giving a selected traffic
   aggregate preferential treatment.  Moreover, it may also exploit all
   unused resources from other PDBs.








Bless, et al.                Informational