Re: [tcpm] I-D Action: draft-ietf-tcpm-1323bis-13.txt

[Yuchung Cheng <[e-mail]>]

On Mon, May 20, 2013 at 1:10 PM, Joe Touch <[e-mail]> wrote:
>
>
>
> On 5/20/2013 12:13 PM, Yuchung Cheng wrote:
>>
>> I suggest removing all these texts;
>>
>> """If a non-<RST> segment is received without a TSopt, a TCP MAY drop
>> the segment and send an <ACK> for the last in-sequence segment.  ""
>> What's the point to ignore a perfectly fine data packet w/o TS-opt and
>> respond a (DUP)ACK? the sender is probably may trigger fast recovery
>> falsely. Responding ACKs is not going to make any forward progress  on
>> buggy implementations or middle-boxes.
>>
>> """ A TCP MUST NOT abort a TCP connection if a non-<RST> segment is
>> received without a TSopt. """
>> TCP should abort only if it's truly in trouble. so let's not
>> re-emphasize the general rule of trying to keep things going until the
>> last minute.
>
>
> The text currently says:
>
>    Once TSopt has been successfully negotiated (sent and received)
>    during the <SYN>, <SYN,ACK> exchange, TSopt MUST be sent in every
>    non-<RST> segment for the duration of the connection, and SHOULD be
>    sent in a <RST> segment (see Section 4.2 for details).  If a non-
>
>    <RST> segment is received without a TSopt, a TCP MAY drop the segment
>    and send an <ACK> for the last in-sequence segment.  A TCP MUST NOT
>
>    abort a TCP connection if a non-<RST> segment is received without a
>    TSopt.
>
> This wording leaves a few ambiguities:
>
> - The first MUST implies some sort of uniform non-RST non-TSopt processing, but the rest of the paragraph doesn't provide it.
>
> - The last sentence implies that receipt of a RST non-TSopt could cause an abort because of the lack of TSopt; it is because 'abort' is the consequence of processed RST.
>
> I suggest clarifying this as:
>
>    Once TSopt has been successfully negotiated (sent and received)
>    during the <SYN>, <SYN,ACK> exchange, TSopt MUST be sent in every
>    non-<RST> segment for the duration of the connection, and SHOULD be
>    sent in a <RST> segment (see Section 4.2 for details).  If a non-
>    <RST> segment is received without a TSopt, a TCP MUST drop the
>    segment
>    and MAY also send an <ACK> for the last in-sequence segment.
>    A TCP MUST NOT abort a TCP connection because any segment lacks
>    an expected TSopt.
I like Joe's text better

>
> Joe