Re: [ledbat] Fwd: New Version Notification for draft-ietf-ledbat-congestion-08.txt

[Arjuna Sathiaseelan <[e-mail]>]

Another thing which I forgot to point out - in section 3.4.1 the term
off_target suddenly pops up without an explanation. That needs to be
resolved please.

Regards
Arjuna


On 15 October 2011 09:37, Arjuna Sathiaseelan <[e-mail]> wrote:
> Dear Jana and others,
>
>  I went through the draft and am currently trying to figure out what
> the performance implications are with the latest draft through
> simulations (I have a few helpful UG students in India who have
> volunteered to do this for me - this includes modifying the current
> ns-2 code to reflect the latest draft). But unfortunately, I dont
> think we will be able to tell anything useful before WGLC ends!
>
> However I have one question ->
>  " A CTO is used to detect heavy congestion indicated by loss of all
>   outstanding data or acknowledgments, resulting in reduction of the
>   cwnd to 1 MSS and an exponential backoff of the CTO interval"
>
> So I am trying to see  whether heavy congestion actually means loss of
> "ALL" outstanding segments - so how does LEDBAT behave according to
> the current draft if atleast one packet went through? Just trying to
> understand.
>
> Regards
> Arjuna
>
> On 10 October 2011 00:51, Janardhan Iyengar <[e-mail]> wrote:
>> Dear all,
>>
>> A new version of the congestion control draft is in the repository. There
>> are two major mods in this revision:
>>
>> 1/ WGLC identified one major issue that needed to be addressed in the LEDBAT
>> congestion control draft -- LEDBAT response to extreme congestion -- and
>> we've tried to address that issue in this revision. We've added a new
>> mechanism, the Congestion Timeout (CTO), for a sender to respond to extreme
>> congestion. We do not specify how this should be implemented, but we do note
>> that a CTO can be implemented with or without a timer. In terms of textual
>> changes, we've added an update_CTO() function and a branch for what to do if
>> no acks are received within a CTO amount of time in Section 3.4.2. We have
>> changed the response to data loss to ensure that a protocol, such as TCP,
>> that uses the same timer for both congestion control and for
>> retransmissions, changes its cwnd correctly.
>>
>> 2/ We have set the values for INIT_CWND to 4 and MIN_CWND to 2, and have
>> clarified the discussion of CURRENT_DELAYS and INIT_CWND/MIN_CWND in Section
>> 3.5.
>>
>> Please comment!
>> - jana
>>
>> --
>> Janardhan Iyengar
>> Assistant Professor, Computer Science
>> Franklin & Marshall College
>> http://www.fandm.edu/jiyengar
>>
>>
>> -------- Original Message --------
>> Subject: New Version Notification for draft-ietf-ledbat-congestion-08.txt
>> Date: Sun, 09 Oct 2011 16:33:33 -0700
>> From: [e-mail]
>> To: [e-mail]
>> CC: [e-mail], [e-mail],
>>  [e-mail], [e-mail]
>>
>> A new version of I-D, draft-ietf-ledbat-congestion-08.txt has been
>> successfully submitted by Janardhan Iyengar and posted to the IETF
>> repository.
>>
>> Filename:        draft-ietf-ledbat-congestion
>> Revision:        08
>> Title:           Low Extra Delay Background Transport (LEDBAT)
>> Creation date:   2011-10-09
>> WG ID:           ledbat
>> Number of pages: 19
>>
>> Abstract:
>>   LEDBAT is an experimental delay-based congestion control algorithm
>>   that attempts to utilize the available bandwidth on an end-to-end
>>   path while limiting the consequent increase in queueing delay on the
>>   path.  LEDBAT uses changes in one-way delay measurements to limit
>>   congestion that the flow itself induces in the network.  LEDBAT is
>>   designed for use by background bulk-transfer applications; it is
>>   designed to be no more aggressive than TCP congestion control and to
>>   yield in the presence of any competing flows when latency builds,
>>   thus limiting interference with the network performance of the
>>   competing flows.
>>
>>
>>
>>
>> The IETF Secretariat
>> _______________________________________________
>> ledbat mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/ledbat
>>
>
>
>
> --
> http://about.me/arjuna.sathiaseelan
>