[Nfd-dev] [ndnSIM] Interest Satisfaction Rate (ISR) Calculation

[David R. Oran]

On 3 Apr 2018, at 10:59, Junxiao Shi wrote:

> Dear folks
>
> I have a related question: what does "Interest satisfaction rate" for 
> a
> nexthop means on a forwarder?
>
> Consider the scenario where a forwarder G has one downstream node C, 
> and
> two upstream nodes (aka nexthops) P and Q:
>
>      /---P
> C---G
>      \---Q
>
> G is using multicast strategy.
> When it receives an Interest from C and forwards it to both P and Q, P
> responds immediately and the Data goes back to C.
> As in a recent NFD commit
> <https://github.com/named-data/NFD/commit/7003e0bc669c113bc112c784119750581b83d2a6>
> (which will appear in ndnSIM sooner or later), there isn't a 
> "straggler
> timer" anymore so the PIT entry is removed immediately.
> Q responds several milliseconds later, at which time the PIT entry at 
> G is
> already gone and G drops the Data.
>
> Should G count a "Interest satisfaction" on nexthop Q, or count a 
> "Interest
> timeout" on nexthop Q, or neither?
Well, you clearly can’t just increment the interest satisfaction 
timer, since that would allow a compromised upstream forwarder to blast 
unrequested data packets in order to divert traffic onto its path.

Conversely (although not quite as bad), counting as an interest timeout 
would penalize an upstream forwarder who in fact just responded second 
(which could be due to something as simple as a slightly longer RTT.)

Doing neither seems the right compromise if one removes PIT state on 
satisfaction rather than just marking the PIT satisfied and cleaning it 
up in a lazy fashion. Unless you’re under memory pressure, leaving the 
satisfied PIT around until the Interest expiration timer goes off is 
likely to be a much better approach overall and renders this question 
moot.

> Note that I'm not asking how ndnSIM's tracer currently behaves, but 
> I'm
> asking how it should be designed, and what's the best design of this
> measurement if a strategy is to use it for forwarding decisions.
>
> Yours, Junxiao
>
> On Thu, Mar 29, 2018 at 1:43 AM, sobia Mirza <sobia.mirza88 at yahoo.com>
> wrote:
>
>> Hi
>> From rate-trace.txt I need to calulate total number of satisfied 
>> interests
>> and total interests. How can i do that?
>>
>> There are InInterests, OutInterests,InSatisfiedInterests,
>> InTimedOutInterests, OutSatisfiedInterests etc.
>> From following which one is actually indicate "number of  satisfied
>> interests" and how "total number of interests" can be calulated???
>>
>>
>>
>>    - InInterests measurements of incoming Interests
>>    - OutInterests measurements of outgoing Interests
>>    - InData measurements of incoming Data
>>    - OutData measurements of outgoing Data
>>    - InNacks measurements of outgoing NACKs
>>    - OutNacks measurements of outgoing NACKs
>>    - SatisfiedInterests measurements of satisfied Interests (totals 
>> for
>>    all faces)
>>    - TimedOutInterests measurements of timed out Interests (totals 
>> for
>>    all faces)
>>    - InSatisfiedInterests measurements of incoming satisfied 
>> Interests
>>    (per incoming face)
>>    - InTimedOutInterests measurements of incoming timed out Interests
>>    (per incoming face)
>>    - OutSatisfiedInterests measurements of outgoing satisfied 
>> Interests
>>    (per outgoing face)
>>    - OutTimedOutInterests measurements of outgoing satisfied 
>> Interests
>>    (per outgoing face)
>>    - as mentioned on page
>>    http://ndnsim.net/current/metric.html
>>
>> regards
>>


> _______________________________________________
> Nfd-dev mailing list
> Nfd-dev at lists.cs.ucla.edu
> http://www.lists.cs.ucla.edu/mailman/listinfo/nfd-dev

DaveO