Re: [arch-d] Call for Comment: <draft-iab-use-it-or-lose-it-02> (Long-term Viability of Protocol Extension Mechanisms)

While I can not speak for others, several things leap out at me.

In terms of packet forwarding, extra processing slows down (and / or 
increases cost) of the forwarding plane.  We do add features when we 
need them.  But using optional unneeded things at random, and hoping 
that everything will work with it, seems a bad trade.
(THis is complicated by the history in which we have done a very bad job 
of making clear to folks that they need to handle the special cases. 
Which is part of the problem you are raising.)

In the routing plane, in contrast, we have so many features that the 
problem is making sure the ones one needs are impleemnted.  Asking folks 
to throw in random additional stuff without meaning seems a difficult 
trade (not as bad as the data plane, but still problematic.)

There is also the dimension that in these layers, the IETF telling folks 
they need to do X, Y, or Z when it gives them no benefit has failed 
repeatedly.  So I am skeptical about that general approach.

As suggested text, something like:

"While many of these techniques have been found beneficial at the upper 
layers of the stack, the tradeoffs in using them at or below the Routing 
system are much more complex, even though the issues themselves are 
equally present."

Yours,
Joel

On 8/25/2021 6:32 PM, Martin Thomson wrote:
> On Thu, Aug 26, 2021, at 05:00, Joel M. Halpern wrote:
>> the proposed approaches to improving
>> the situation are likely to be problematic at best
> 
> The document suggests several approaches, can you be more specific?  (I can see how any number of these might be infeasible, but I want to understand your point better.
> 
>> a much stronger disclaimer is needed
> 
> Do you have a suggestion?
> 
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