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

From: Alejandro Acosta <[email-masked]>
Date: Sun, 28 Apr 2013 21:29:47 -0430

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 %

- 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

- 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.

- 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