Subject: [Tsvwg] I-D Action:draft-ietf-tsvwg-udp-guidelines-02.txt

From: [email-masked]
Date: Mon, 09 Jul 2007 05:50:01 -0400

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Transport Area Working Group Working Group of the IETF.

        Title           : UDP Usage Guidelines for Application Designers
        Author(s)       : L. Eggert, G. Fairhurst
        Filename        : draft-ietf-tsvwg-udp-guidelines-02.txt
        Pages           : 15
        Date            : 2007-07-09
                                                                                           
The User Datagram Protocol (UDP) provides a minimal, message-passing
transport that has no inherent congestion control mechanisms.
Because congestion control is critical to the stable operation of the
Internet, applications and upper-layer protocols that choose to use
UDP as an Internet transport must employ mechanisms to prevent
congestion collapse and establish some degree of fairness with
concurrent traffic.  This document provides guidelines on the use of
UDP for the designers of such applications and upper-layer protocols
that cover congestion-control and other topics, including message
sizes, reliability, checksums and middlebox traversal.
                                                                                           
A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-tsvwg-udp-guidelines-02.txt
                                                                                           
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From: Colin Perkins <[email-masked]>
Date: Mon, 23 Jul 2007 11:20:06 -0500

> http://www.ietf.org/internet-drafts/draft-ietf-tsvwg-udp- 

Section 3.5 states:

    Applications MAY in addition send periodic keep-alive messages to
    attempt to refresh middlebox state.  Unfortunately, no common  
timeout
    has been specified for per-flow UDP state for arbitrary middleboxes.
    For NATs, [RFC4787] requires a state timeout of 2 minutes or longer,
    and it is likely that other types of middleboxes use timeouts of
    similar timescales.  Consequently, if applications choose to send
    periodic keep-alives, they SHOULD NOT send them more frequently than
    once every two minutes.  (Not that some deployed middleboxes use a
    shorter timeout value than 2 minutes, violating [RFC4787].)

which is fine, except that draft-ietf-mmusic-ice-17 suggests a 15  
second keep alive interval by default. Can we align these?

-- 
Colin Perkins
http://csperkins.org/