[e2e] Why do we need congestion control?

[LOCHIN Emmanuel]

Le 02.04.2013 14:53, Detlef Bosau a écrit :
> Am 02.04.2013 13:20, schrieb shun cai:
>
>> Hi，
>>
>> I found two papers which state that with ideal fountain code,there
>> is generally no congestion collapse.Efficiency remains higher than
>> 90% for most network topologiesas long as maximum source rates are
>> less than link capacity by one or two orders of magnitude. Moreover,
>> a simple fair drop policy enforcing fair sharing at flow level is
>> sufficient to guarantee 100% efficiency in all cases. I refer to
>> several papers on the congestion problem when fountain code is used.
>> [1] [2]
>  Don't we compare peaches and oranges here?
>
>  When we talk about TCP, we talk about a reliable protocol. Are
> digital fountain codes reliable??

Hi Detlef

In these papers the authors consider "perfect code", meaning that all 
the redundancy is useful.
Look at our implementation of Decongestion Control Protocol : 
http://www.lochin.net/tetrysjungle.pdf
where full reliability is achieved without retransmission.

Manu