Re: [Pals] [Int-area] L2TP sequencing: Commonly disabled for IP data? Or always?

Bob Briscoe <ietf@bobbriscoe.net> Tue, 29 June 2021 10:24 UTC

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To: Derek Fawcus <dfawcus+lists-int-area@employees.org>, pals@ietf.org, intarea IETF list <int-area@ietf.org>
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From: Bob Briscoe <ietf@bobbriscoe.net>
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Date: Tue, 29 Jun 2021 11:23:59 +0100
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Subject: Re: [Pals] [Int-area] L2TP sequencing: Commonly disabled for IP data? Or always?
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Derek,

On 28/06/2021 19:46, Derek Fawcus wrote:
> On Mon, Jun 28, 2021 at 09:39:34AM +0100, Bob Briscoe wrote:
>> My attempt to generalize this UK-specific knowledge: No-one is going to
>> add sequencing without a reason, and the only possible reason mentioned
>> so far would be stateful compression, which these days would just slow
>> things down more than the bandwidth saved.
> I also mentioned PWE fragmentation - rfc4623 - it depends upon the sequence
> numbers as a fragment identifier.  So depending upon how it is implemented,
> it may implicitly turn on sequencing, without the user knowing.
>
> So the related question then becomes, where is that fragmentation support
> being used - if anywhere?

[BB] Sorry, I omitted to explain that, in the PWE case, I didn't think 
differential delay would be a problem, because all traffic in the PWE 
would be expected to want the same low delay service. My concern was 
about sequencing of tunnelled packets undoing deliberately 
differentiated delay between different types of IP traffic within an 
aggregate.

But thanks for picking me up on not explaining that.

Cheers


Bob

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