[e2e] local recovery or not local recovery, was: Re: Satellite networks latency and data corruption
Detlef Bosau
detlef.bosau at web.de
Tue Jul 5 08:31:40 PDT 2005
alok wrote:
>
>> For 3G networks, my position is that the gateways between Internet and
>> mobile network are typically quite large computer systems, each one
>> serving some few hundreds of flows. In this case, the effort is
>> acceptable.
>>
>> In satellite networks: I don´t know. Particularly the state variables
>> for ARQ in high bandwidth systems may turn out inacceptable high.
>>
>> 2.: Fairness:
>>
>> If ARQ is placed on the end system, the whole network path "enjoys"
>> necessary retransmissions. Particularly, when a packet must be sent
>> 100 times or more to be successfuly received ad least once, it may
>> increase the network performance to plate ARQ on intermediate sywtems.
>>
> if it is wire line/fibre, i think we do not have to worry about losses.
>
>> Once again on 3G networks: Typically, 3G networks are only used as
>> access line. So the major part of the path typically resides in the
>> wirebound internet. Therefore, it makes sense not to bother ther
>> internet with retransmissions. Even more, ARQ in 3G networks is done
>> on radio block level, which is more efficient than ARQ on pakcet level.
>>
> well I did see your website, but ....what is "3G"?
Third Generation mobile networks.
http://www.3gpp.org/
I think "Third Generation Wide Area Mobile Networking and Ubiquitous
Computing" sounds better - therefore sells better than: UMTS :-) *SCNR*
> it does not use anything but the same fiber and copper or media than was
> already there, right?
>
Yes, I think the wireless media was already there ;-) (There must be
some papers by James C. Maxwell about this.... and certainly, JC will
add: another british invention/discovery, however: JCM was a scot :-))
>> This is mainly covered by 2. Fairness.
>>
>> Of couse, the utilization of a link decreases if it is fed up with
>> retransmissions only.
>>
>> I think, the consideration can turn out quite different, depending on
>> the actual scenario: E.g. a satellite mobile phone could be attached
>> to the Internnet. Or a satellite link could be used for Internet
>> backbone connections, perhaps wheather dependent in combination with a
>> fibre link.
>>
> By fairness, do you mean that "i use up someone else's
> space/time/bandwidth"? no that is not what I was asking. What on the
> internet is "fairness"?
In this particular case I meant: I do not use more bandwidth for
retransmission than others do.
Basically, fairness on the Internet means that competing flows use a
fair share of common ressources.
--
Detlef Bosau
Galileistrasse 30
70565 Stuttgart
Mail: detlef.bosau at web.de
Web: http://www.detlef-bosau.de
Mobile: +49 172 681 9937
More information about the end2end-interest
mailing list