AD comments on draft-ietf-rserpool-policies-06

Hi,

Some comments on the policies document

1. In a number of places I find this document talking about policies
returning multiple PEs in answer. However, I can't remember any requests
that support asking for multiple answers. So please inform me how this
was intended to use. Or if not currently supported what the intention
was with specifying this for the policies.

2. Section 5.2.2:
I think one need to clarify that this policy should be selecting the
pool element that gets the lowest value when calculating: load value +
degradation counter * load degradation

Forgetting to multiply the load degradation factor with the counter of
loads assigned I think miss the whole purpose of this policy.

3. Section 5.4.1:
"ratio of 100%-load to
   the sum of all pool elements' load values."

I think you should change this formula. I first interpreted the minus
sign as continunation but that didn't make much sense. Also I think 100%
needs to be represented as it is in the protocol with 0xFFFFFFFF.

Also shouldn't the used ratio be = (0xFFFFFFFF - load_A) /
(sum(0xFFFFFFFF-load_x)) i.e. this PE's unload part related to the whole
pools unload rate. I think that makes more sense than to calculate it as
unloaded divided by the sum of the total load.

4. Section 6.

Shouldn't this section discuss the sensitivity the different policies
has against different type of attacks. For example if an ENRP gets a lot
of requests for a particular pool and it used a least used policy that
requires the PE to update its load, then all these requests will end
pointing to that particular PE. So it is sensitive to flash floods of
requests. I think there are other considerations that also should be
noted about the policies.

5. Section 7.1: I can't understand what the policy is for value
0x80000000-0xFFFFFFFF. Is that also specification required, can't be
registered? To me it seems this range would be best served by first come
first served.


-- 

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
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