Re: [Dime] Mirja Kühlewind's Discuss on draft-ietf-dime-drmp-05: (with DISCUSS and COMMENT)

[Alexey Melnikov <[e-mail]>]

Hi Mirja,

On 10 May 2016, at 17:59, Mirja Kuehlewind (IETF) <[e-mail]> wrote:

>>> I don’t think it is a good idea to assign a default priority to non-priority-defined requests at all. If you have high priority traffic that does not support this extension (yet) this traffic could be starved by lower priority traffic when assigning a middle range priority. I don’t think that is what you want to achieve.
>> SRD> Actually, this is what we want to achieve.  It is an requirement that messages explicitly marked as high priority get treated even if it results in starving lower priority messages.  The starving of lower priority messages is not an problem, it is a requirement.
> 
> I think we are still talking past each other.

Most definitely :-).

> If you explicitly assign a priority, starvation might be okay. However, if you don’t have a priority explicitly signaled, the transaction might have a very high priority

So some agent in the system needs to decide that a transaction is important.
> but you just don’t know and by assigning a random mid-range priority this important request could get starved.

Here I disagree with you, because the way to know that a transaction is important is to upgrade client to explicitly assign high priority to it. So default priority is a backward compatibility mechanism, that would work for most common cases. You seem to be suggesting that when this extension is deployed all clients need to be updated at the same time. This is not realistic.