Re: [ericas] Examples of Internet protocols not working well in emergent regions

[Andrés Arcia-Moret <[e-mail]>]

Hello 

This is an interesting proposal. Nowadays I'm working at the International Centre of Theoretical Physics (Italy), specifically at Marconi Lab.

http://wireless.ictp.it/

At the wireless lab we're mainly interested in bringing the Internet technologies to emerging regions. So, I'll be willing to participate. 

Alejandro, I have some questions regarding your mail, so I write them between lines.


On Apr 29, 2013, at 3:59 AM, Alejandro Acosta <[e-mail]> wrote:

> Hi Arturo,
>  This is a copy/paste from the mailing list archive. I just subscribed.
>  Regarding satellite networks I can mention few things.
>  Some toughs:
> 
> - TCP spoofing increases and improves a lot satellite links. I fully
> recommend it. Very, very few problems reported when using TCP
> spoofing, mainly some https connections. But one more time, almost
> none. The improvement is over >25 %

spoofing like in the PEP approach at BT? or do you rather mean *snooping*?

> 
> - Andres Arcia (co-author of RFC 5690, on cc) has some recommendations
> in this respect since he has done several studies in this area. He
> recommends different handling of tcp acks, he has already some
> Linux-modified kernels to test. We've also gathered a lot of data and
> we can continue testing some things.
> 
> - Delay looks (and it's) impossible to improve

In what sense?

> 
> - VoIP runs ok using SIP with QoS and good tunning of g.729 (better
> than what most documents say). I don't recall the MOS but anyway it's
> very good.
> 
> - SCPC links are extremely expensive (anywhere in the world), I think
> the trend is to move to eSCPC over some VSAT technologies
> 
> - Transactional information (ATMs, Point of Sale) work just fine over
> regular VSAT (no eSCPC). Please be careful if VPNs+routing protocols
> run on this links, if so,, it's no any longer transactional.
> 
> - Let's remember that most satellite link are asymmetric.

and so, AckCC may be of use (RFC 5690). See also:
 
http://www.saber.ula.ve/handle/123456789/31038


> 
> - Regarding bandwidth I can only think in good compression
> technologies built in modems, more gzip in http.
> 
> just my two cents,
> 
> Alejandro Acosta,
> 
> 
> -----
> 
>    From: Arturo Servin <arturo.servin at gmail.com>
>    To: ericas at irtf.org
>    Date: Sun, 28 Apr 2013 22:19:04 -0300
>    List-id: "Discussion list for \"Emerging Regions Internet
> Challenges And Solutions\" \(ERICAS\) " <ericas.irtf.org>
> 
> 	Some ideas of possible challenges for the IP suite in emergent regions:
> 
> 	- Long delay networks
> 	- Low bandwidth networks
> 	- Satellite networks (which are low BW and have long delays)
> 	- Mesh wireless networks
> 	- Networks not connected all the time
> 	- Not reliable/slow backup networks (i.e. in many countries there is
> just one ISP, how can we provide multi-home for critical services using
> a not very reliable backup link, for example a satellite link, a 3/4G,
> dial-up, etc.)
> 	
> 	These are the problems that for instance, I suffer or I know people
> that do. Nevertheless I imagine there should be many more of these.
> 
> 	I imagine that a first step would be to document a set of problems on
> which we could try to solve.
> 
> 	
> Regards,
> as

-
A/A/