Re: [aqm] Benoit Claise's No Objection on draft-ietf-aqm-pie-07: (with COMMENT)

["Rong Pan (ropan)" <[e-mail]>]

Please see inline.

Thanks,

Rong

>
>
>
>----------------------------------------------------------------------
>COMMENT:
>----------------------------------------------------------------------
>
>- Support Ben's comment:
>
>It would be nice to see some text about the nature of the "experiment".
>That is, why is this experimental? Do you expect to promote this to a
>standard in the future? (The shepherd's report speaks of this; the draft
>
>should, too)
>
>ex: https://tools.ietf.org/html/rfc6614#section-1.3


Waiting for Chair¹s comments...


>
>- Minor personal preference: delay variation instead of jitter.
>See https://tools.ietf.org/html/rfc5481#section-1 for a justification.
>Btw, same comment for draft-ietf-aqm-eval-guidelines-11, which I forgot
>to mention.
>
>- Section 1
>RFC2309 is obsolete:
>
>   RFC 2309[RFC2309]
>   strongly recommends the adoption of AQM schemes in the network to
>   improve the performance of the Internet.
>
>Not sure why [RFC2309] is different than [IETF-AQM], which is now
>RFC7567. So maybe using [RFC2309] was used on purpose.




RFC2309 is mentioned as it highly recommends AQM like RED, which is why
RED has
found wide-adoption. It is mentioned to indicate the history of AQM
designs.
Changed IETF-AQM to RFC7567.




>
>
>- it seems that you sometimes interchange queueing latency, latency,
>delay, queue delay
>For an example, review section 3 and section 4 first paragraph.
>You should really use consistent terms, for example queueing latency,
>throughout the document.
>
>OLD:
>
>As illustrated in Fig. 1, PIE conceptually comprises three simple MUST
>components: a) random dropping at enqueueing; b) periodic drop
>probability update; c) latency calculation. When a packet arrives, a
>random decision is made regarding whether to drop the packet. The drop
>probability is updated periodically based on how far the current delay
>is away from the target and whether the queueing delay is currently
>trending up or down. The queueing delay can be obtained using direct
>measurements or using estimations calculated from the queue length and
>the dequeue rate.
>
>NEW:
>As illustrated in Fig. 1, PIE conceptually comprises three simple MUST
>components: a) random dropping at enqueueing; b) periodic drop
>probability update; c) queueing latency calculation. When a packet
>arrives, a
>random decision is made regarding whether to drop the packet. The drop
>probability is updated periodically based on how far the current queueing
>latency
>is away from the target and whether the queueing latency is currently
>trending up or down. The queueing latency can be obtained using direct
>measurements or using estimations calculated from the queue length and
>the dequeue rate.
>
>
>NEW:
>
>        Random Drop
>             /               --------------
>     -------/  -------------->    | | | | | -------------->
>            /|\                   | | | | |
>             |               --------------
>             |             Queue Buffer   \
>             |                     |       \
>             |                     |queue   \
>             |                     |length   \
>             |                     |          \
>             |                    \|/         \/
>             |          -----------------    -------------------
>             |          |     Drop      |    | Queueing        |
>             -----<-----|  Probability  |<---| Latency         |
>                        |  Calculation  |    | Calculation     |
>                        -----------------    -------------------
>


Done. 



>
>
>- terminology: dequeue_rate or departure?
>    Section 4.2 =>"dequeue rate"
>    Section 4.3
>
>        current_qdelay = queue_.byte_length()/dequeue_rate;
>
>    Section 5.2 Departure Rate Estimation
>    Section 5.2 typo "Upon a packet deque:"  (this one could fine if you
>speak about the
>                  
>deque(Packet packet) function, but that's not clear)
>Again, be consistent across the entire doc.

I have changed departure to dequeue to be clear.


>
>- editorial: missing reference links
>
>   CBQ has been a standard feature in most network devices today[CBQ]
>
>    The controller parameters, alpha and beta(in the unit of hz) are
>    designed using feedback loop analysis where TCP's behaviors are
>modeled
>    using the results from well-studied prior art[TCP-Models].



These are in? [CBQ] Cisco White Paper,
"http://www.cisco.com/en/US/docs/12_0t/12_0tfeature/guide/cbwfq.html".

  [TCP-Models] Misra, V., Gong, W., and Towsley, D., "Fluid-base
Analysis of a Network of AQM Routers Supporting TCP Flows with an
Application to RED", SIGCOMM 2000



Maybe because of special control characters (that I need to fix), they
don¹t show up? I will look into these.




>
>
>- editorial:
>
>   This draft separates the PIE design into the basic elements that are
>   MUST to be implemented and optional SHOULD/MAY enhancement elements.
>
>NEW:
>   This draft separates the PIE design into the basic elements that
>   MUST to be implemented and optional SHOULD/MAY enhancement elements.
>
>


Done. 



>