RFC 3148 (rfc3148) - Page 1 of 16
A Framework for Defining Empirical Bulk Transfer Capacity Metrics
Alternative Format: Original Text Document
Network Working Group M. Mathis
Request for Comments: 3148 Pittsburgh Supercomputing Center
Category: Informational M. Allman
BBN/NASA Glenn
July 2001
A Framework for Defining Empirical Bulk Transfer Capacity Metrics
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
This document defines a framework for standardizing multiple BTC
(Bulk Transport Capacity) metrics that parallel the permitted
transport diversity.
1 Introduction
Bulk Transport Capacity (BTC) is a measure of a network's ability to
transfer significant quantities of data with a single congestion-
aware transport connection (e.g., TCP). The intuitive definition of
BTC is the expected long term average data rate (bits per second) of
a single ideal TCP implementation over the path in question.
However, there are many congestion control algorithms (and hence
transport implementations) permitted by IETF standards. This
diversity in transport algorithms creates a difficulty for
standardizing BTC metrics because the allowed diversity is sufficient
to lead to situations where different implementations will yield
non-comparable measures -- and potentially fail the formal tests for
being a metric.
Two approaches are used. First, each BTC metric must be much more
tightly specified than the typical IETF protocol. Second, each BTC
methodology is expected to collect some ancillary metrics which are
potentially useful to support analytical models of BTC.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC 2119]. Although
Mathis, et al. Informational