Re: [tsvwg] Adoption call for draft-white-tsvwg-l4sops - to conclude 24th March 2021

[Bob Briscoe <[e-mail]>]

Steven,

On 24/03/2021 23:12, Steven Blake wrote:
> On Wed, 2021-03-24 at 22:50 +0000, Bob Briscoe wrote:
>> Steven,
>>
>>
>> On 23/03/2021 00:56, Steven Blake wrote:
>>> Sec. 4 (Operator of a Network) of the draft presumes that deployed
>>> equipment is capable to classifying packets specifically on ECT(1).
>>> Have the authors confirmed that this feature is available on
>>> commonly
>>> deployed operator gear (e.g., IOS-XR, JUNOS)?
>> [BB]
>> (Aside: I think you're reading an old (-01) draft. That section has
>> been
>> Sec. 5. since draft-02 on 22 Feb 2021.
>> See my response to the initial adoption call about the probable cause
>> of
>> this confusion - suspected problems with the IETF tools servers.
>> )
> Oops! You're right. s/Sec. 4/Sec. 5.
>
>
>> To your point, I checked the manuals of one or two OSs of common
>> makes
>> of router before I proposed the WRED technique for addition to the
>> draft. And I discussed the hardware capabilities with people within
>> one
>> or two router vendors. In the cases I checked, the CLI limits the
>> flexibility that the admin has to define classifiers as general bit
>> patterns. However the hardware underneath does have that flexibility.
>> So
>> this would require a CLI update for the routers I checked. The Linux
>> classifier architecture does provide sufficient flexibility for such
>> a
>> classifier.
>>
>> I also suggested the ECT(1) tunnel bypass technique, but I didn't
>> exhaustively check the manuals of all the different types of tunnel
>> (there are dozens).
>>
>> I think this list of techniques is most useful for router
>> developers,
>> who can then find the easiest and most efficient one for their
>> particular kit; whether they have to update the CLI, or whether they
>> can
>> find a way for their users to configure their unmodified systems in
>> the
>> field.
>
> So operators that *don't wish to participate in L4S experiments* may
> need to update *their* deployed software? Ask your favorite router
> vendor how many customer-specific releases they are maintaining because
> customers don't want to move forward once they get a working validated
> release.

[BB] There is a common belief that, if any RFC3168 FIFO AQMs exist, they 
will be rare. But Jake and Jonathan raised the concern that it still 
needs to be possible to deploy RFC3168 routers from now onwards. In that 
case, operators that *don't wish to participate* would be updating their 
config, and l4sops then gives router developers ideas for how they might 
be able to prevent an existing implementation of RFC3168 from acting on 
ECT(1), given an ECN implementation is likely to be hard-coded against 
the ECN codepoints.



Bob

>
>
> Regards,
>
> // Steve
>
>
>
>

-- 
________________________________________________________________
Bob Briscoe                               http://bobbriscoe.net/