[tsvwg] Last Call: <draft-ietf-tsvwg-rfc5405bis-13.txt> (UDP Usage Guidelines) to Best Current Practice

[Ca By <[e-mail]>]

On Sunday, June 5, 2016, Jim Roskind <[e-mail]
<javascript:_e(%7B%7D,'cvml','[e-mail]');>> wrote:

>
>
> On Sat, Jun 4, 2016 at 5:25 PM, Tom Herbert <[e-mail]> wrote:
>
>> On Thu, Jun 2, 2016 at 3:11 AM, Brian Trammell <[e-mail]> wrote:
>> > Greetings, all,
>> >
>> > Apologies for the late last call comment; I have only one, relatively
>> minor. I hope it's still useful.
>> >
>> > I understand that Section 3 was written to encourage application
>> developers not to roll their own transports ("trust us when we say this is
>> hard, this document is a list of reasons why") but as written it would seem
>> to discourage transport innovation atop UDP (e.g. QUIC, the RTCWEB data
>> channel, anything-over-PLUS), which I very much hope was not the intent.
>> The problematic recommendation is in the second paragraph:
>> >
>> >    These mechanisms are difficult to implement correctly.  For most
>> >    applications, the use of one of the existing IETF transport protocols
>> >    is the simplest method of acquiring the required mechanisms.  Doing
>> >    so also avoids issues that protocols using a new IP protocol number
>> >    face when being deployed over the Internet, where middleboxes that
>> >    only support TCP and UDP are not rare.  Consequently, the RECOMMENDED
>> >    alternative to the UDP usage described in the remainder of this
>> >    section is the use of an IETF transport protocol such as TCP
>> >    [RFC0793], Stream Control Transmission Protocol (SCTP) [RFC4960], and
>> >    SCTP Partial Reliability Extension (SCTP-PR) [RFC3758], or Datagram
>> >    Congestion Control Protocol (DCCP) [RFC4340] with its different
>> >    congestion control types [RFC4341][RFC4342][RFC5622].
>> >
>> > First, this paragraph ignores potential deployment issues with any of
>> these other than TCP, which risks seeming out of touch, but this is a minor
>> point and probably not worth a late edit. Second, I'm concerned this
>> recommendation could be taken as broader than intended, against the
>> definition of any new transport protocol encapsulated within UDP that
>> performs substantially the same function as the listed protocols.
>> >
>> I would agree, this paragraph also seems a little self
>> contradictory.There is an acknowledgment that "middleboxes that only
>> support TCP and UDP are not rare", but then the next sentence
>> recommends the use of several other protocols besides UDP and TCP. If
>> I put these two together, the only congested controlled protocol that
>> is recommended and expected to work on the Internet is TCP.
>>
>
> +1   TCP (implemented in kernel space) can't possibly evolve congestion
> avoidance as fast as the Internet has changed, or will change (example:
> good handling of middle boxes that use "policers" rather than some flavor
> of buffer-size based packet-drop).
> The rationale for using UDP for QUIC was indeed that a new IP number would
> never make it through the Internet (other protocol deployment attempts have
> commonly verified this).  It turns out that even UDP is partially blocked
> (as recently as 2011) by paths to 5-7% of all chrome clients, which lead to
> the "automated fallback" elements of QUIC,
>
>
I think this changes with ipv6, no?  Google sees over 26% ipv6 in the usa
and growing quickly

http://www.google.com/intl/en/ipv6/statistics.html

And there is evidence that middle boxes go away in ipv6. .... So perhaps
the world is changing and your assuptions do not hold



>
>
Hopefully the benefits that QUIC is bringing to the Internet will not be
> outlawed (precluded by such commentary).
>
> Jim
>
>
>>
>> Tom
>>
>> > I think this can be made clearer by simply adding to the list of
>> examples:
>> >
>> > NEW:
>> >
>> >    These mechanisms are difficult to implement correctly.  For most
>> >    applications, the use of one of the existing IETF transport protocols
>> >    is the simplest method of acquiring the required mechanisms.  Doing
>> >    so also avoids issues that protocols using a new IP protocol number
>> >    face when being deployed over the Internet, where middleboxes that
>> >    only support TCP and UDP are not rare.  Consequently, the RECOMMENDED
>> >    alternative to the UDP usage described in the remainder of this
>> >    section is the use of an IETF transport protocol such as TCP
>> >    [RFC0793], Stream Control Transmission Protocol (SCTP) [RFC4960], and
>> >    SCTP Partial Reliability Extension (SCTP-PR) [RFC3758], or Datagram
>> >    Congestion Control Protocol (DCCP) [RFC4340] with its different
>> >    congestion control types [RFC4341][RFC4342][RFC5622], or transport
>> >    protocols specified by the IETF in the future.
>> >
>> > and removing the examples from the summary in section 7:
>> >
>> > OLD:
>> >
>> >    | SHOULD use a full-featured transport (TCP, SCTP, DCCP)  |         |
>> >
>> > NEW:
>> >
>> >    | SHOULD use a full-featured transport                    |         |
>> >
>> > Thanks, cheers,
>> >
>> > Brian
>> >
>> >
>> >> On 18 May 2016, at 02:17, The IESG <[e-mail]> wrote:
>> >>
>> >>
>> >> The IESG has received a request from the Transport Area Working Group
>> WG
>> >> (tsvwg) to consider the following document:
>> >> - 'UDP Usage Guidelines'
>> >>  <draft-ietf-tsvwg-rfc5405bis-13.txt> as Best Current Practice
>> >>
>> >> The IESG plans to make a decision in the next few weeks, and solicits
>> >> final comments on this action. Please send substantive comments to the
>> >> [e-mail] mailing lists by 2016-05-31. Exceptionally, comments
>> may be
>> >> sent to [e-mail] instead. In either case, please retain the
>> >> beginning of the Subject line to allow automated sorting.
>> >>
>> >> Abstract
>> >>
>> >>
>> >>   The User Datagram Protocol (UDP) provides a minimal message-passing
>> >>   transport that has no inherent congestion control mechanisms.  This
>> >>   document provides guidelines on the use of UDP for the designers of
>> >>   applications, tunnels and other protocols that use UDP.  Congestion
>> >>   control guidelines are a primary focus, but the document also
>> >>   provides guidance on other topics, including message sizes,
>> >>   reliability, checksums, middlebox traversal, the use of ECN, DSCPs,
>> >>   and ports.
>> >>
>> >>   Because congestion control is critical to the stable operation of the
>> >>   Internet, applications and other protocols that choose to use UDP as
>> >>   an Internet transport must employ mechanisms to prevent congestion
>> >>   collapse and to establish some degree of fairness with concurrent
>> >>   traffic.  They may also need to implement additional mechanisms,
>> >>   depending on how they use UDP.
>> >>
>> >>   Some guidance is also applicable to the design of other protocols
>> >>   (e.g., protocols layered directly on IP or via IP-based tunnels),
>> >>   especially when these protocols do not themselves provide congestion
>> >>   control.
>> >>
>> >>   This document obsoletes RFC5405 and adds guidelines for multicast UDP
>> >>   usage.
>> >>
>> >>
>> >>
>> >>
>> >> The file can be obtained via
>> >> https://datatracker.ietf.org/doc/draft-ietf-tsvwg-rfc5405bis/
>> >>
>> >> IESG discussion can be tracked via
>> >> https://datatracker.ietf.org/doc/draft-ietf-tsvwg-rfc5405bis/ballot/
>> >>
>> >>
>> >> No IPR declarations have been submitted directly on this I-D.
>> >>
>> >>
>> >
>> >
>> > _______________________________________________
>> > Spud mailing list
>> > [e-mail]
>> > https://www.ietf.org/mailman/listinfo/spud
>> >
>>
>> _______________________________________________
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>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/quic
>>
>
>