--- 1/draft-ietf-roll-trickle-00.txt 2010-04-11 01:11:12.000000000 +0200 +++ 2/draft-ietf-roll-trickle-01.txt 2010-04-11 01:11:12.000000000 +0200 @@ -1,19 +1,23 @@ Networking Working Group P. Levis Internet-Draft Stanford University Intended status: Informational T. Clausen -Expires: September 24, 2010 LIX, Ecole Polytechnique - March 23, 2010 +Expires: October 12, 2010 LIX, Ecole Polytechnique + J. Hui + Arch Rock Corporation + J. Ko + Johns Hopkins University + April 10, 2010 The Trickle Algorithm - draft-ietf-roll-trickle-00 + draft-ietf-roll-trickle-01 Abstract The Trickle algorithm allows wireless nodes to exchange information in a highly robust, energy efficient, simple, and scalable manner. Dynamically adjusting transmission windows allows Trickle to spread new information on the scale of link-layer transmission times while sending only a few messages per hour when information does not change. A simple suppression nechanism and transmission point selection allows Trickle's communication rate to scale @@ -34,21 +38,21 @@ and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on September 24, 2010. + This Internet-Draft will expire on October 12, 2010. Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -206,45 +210,50 @@ 2. Whenever Trickle hears a transmission that is "consistent," it increments counter c. 3. At time t, Trickle transmits if and only if counter c is less than the redundancy constant k. 4. When an interval expires, Trickle doubles the interval length. If this new interval length would be longer than Imax, Trickle sets the interval length I to be Imax. - 5. If Trickle hears a transmission that is "inconsistent" and I is - greater than Imin, Trickle resets I to Imin, and begins a new - interval. + 5. If Trickle hears a transmission that is "inconsistent," the + Trickle timer resets. If I is greater than Imin, resetting a + Trickle timer sets I to Imin and begins a new interval. If is + equal to Imin, resetting a Trickle timer does nothing. Trickle + may also reset the timer in response to external "events." - The terms consistent and inconsistent are in quotes because their - meaning depends on the use of Trickle. + The terms consistent, inconsistent and event are in quotes because + their meaning depends on the use of Trickle. 5. Using Trickle - A protocol specification that uses Trickle should specify: + A protocol specification that uses Trickle MUST specify: o Default values for Imin, Imax, and k. Because link layers can vary widely in their properties, the default value of Imin should be specified in terms of the worst-case latency of a link layer transmission. For example, a specification should say "the default value of Imin is 4 times the worst case link layer latency" and should not say "the default value of Imin is 500 milliseconds." Worst case latency is the time until the first link-layer transmission of the frame assuming an idle channel (does not include backoff, virtual carrier sense, etc.). o What constitutes a "consistent" transmission. o What constitutes an "inconsistent" transmission. + o Any "events" besides inconsistent transmissions that reset the + Trickle timer. + 6. Operational Considerations It is RECOMMENDED that a protocol which uses Trickle include mechanisms to inform nodes of configuration parameters at runtime. However, it is not always possible to do so. In the cases where different nodes have different configuration parameters, Trickle may have unintended behaviors. This section outlines some of those behaviors as an educational exercise. 6.1. Mismatched redundancy constants @@ -326,10 +335,27 @@ USA Phone: +1 650 725 9064 Email: pal@cs.stanford.edu Thomas Heide Clausen LIX, Ecole Polytechnique Phone: +33 6 6058 9349 Email: T.Clausen@computer.org + + Jonathan Hui + Arch Rock Corporation + 501 Snd St., Suite 410 + San Francisco, CA 94107 + USA + + Email: jhui@archrock.com + + JeongGil Ko + Johns Hopkins University + 3100 Wyman Park Dr., Room 414 + Baltimore, MD 21211 + USA + + Phone: +1 410 516 4312 + Email: jgko@cs.jhu.edu