RFC 3662 Lower Effort PDB

This document proposes a differentiated services per-domain behavior (PDB) whose traffic may be "starved" (although starvation is not strictly required) in a properly functioning network. This is in contrast to the Internet’s "best-effort" or "normal Internet traffic" model, where prolonged starvation indicates network problems. In this sense, the proposed PDB’s traffic is forwarded with a "lower" priority than the normal "best-effort" Internet traffic, thus the PDB is called "Lower Effort" (LE). Use of this PDB permits a network operator to strictly limit the effect of its traffic on "besteffort"/"normal" or all other Internet traffic. This document gives some example uses, but does not propose constraining the PDB’s use to any particular type of traffic. 1. Description of the Lower Effort PDB This document proposes a differentiated services per-domain behavior [RFC3086] called "Lower Effort" (LE) which is intended for traffic of sufficiently low value (where "value" may be interpreted in any useful way by the network operator), in which all other traffic takes precedence over LE traffic in consumption of network link bandwidth. One possible interpretation of "low value" traffic is its low priority in time, which does not necessarily imply that it is generally of minor importance. From this viewpoint, it can be Bless, et al. Informational [Page 1] 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 "besteffort" (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) [RFC3086] 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 [RFC2474].