dhis2-users team mailing list archive

["Dapo Adejumo" <dapo_adejumo@xxxxxxxxx>]

Hi Jason,
Thanks for the comprehensive response. Performing a trace route is a good idea.
Sent from my BlackBerry® wireless handheld from Glo Mobile.

-----Original Message-----
From: Jason Pickering <jason.p.pickering@xxxxxxxxx>
Date: Mon, 14 Nov 2011 08:42:50 
To: Dapo Adejumo<dapo_adejumo@xxxxxxxxx>
Cc: dhis2-devs<dhis2-devs@xxxxxxxxxxxxxxxxxxx>; <dhis2-users@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Dhis2-devs] Internet Speed

Hi Dapo,

Our experience has been that the bandwidth makes little difference. It has
a lot more to do about the latency and how users are able to access it. In
Zambia, some traffic goes through VSAT while in some cases it is router
through a fiber connection. In both cases, the traffic get routed through
London however. Ideally, you would wan to avoid a trans-Atlantic hop (i.e.
with a server located in America) as usually the latency is much longer,
and the connection therefore seems to be much slower. If you can physically
locate the server in Nigeria, this may be better, but we have also seen
situations were ISPs route information first to London and then to Zambia.
 So just because the server is local, does not always mean it is faster.
This of course is not ideal, but it can happen. So, if you can perform a
traceroute from your clients to see where most of them are coming from, and
how they are able to reach the ISP with the lowest level of latency, then
this should result in a seemingly faster connection.

Of course, you must have a reasonable bandwidth, but normally you are going
to be constrained by the downstream bandwidth of the client, and not the
upstream bandwidth of the server. This is normally why the latency is much
more important than the upstream bandwidth of the server. However, locating
servers in location with very low upstream bandwidth (say less than 1
MBit/sec), then you are definitely going to feel that the connection is
slower. Most ISPs have upstream bandwidth much greater than that figure, so
you would not want to choose any ISP which offers 64kb/sec contested
bandwidth upstream, even if the latency is small.

So, in summary, based on our experience here, it is a combination of
several factors 1) Server speed 2) Latency 3) Server upstream
bandwidth. Since we are using a London based ISP however here, the third
factor has never ever been an issue however.

Just a few thoughts.

Best regards,
Jason


On Mon, Nov 14, 2011 at 8:25 AM, Dapo Adejumo <dapo_adejumo@xxxxxxxxx>wrote:

> Dear All,
> Please what will you recommend as minimum internet speed  for most
> users(download and upload) for online deployments of dhis2 . I would
> appreciate experiences from developing countries.
>
> Thank you.
>
>
> ------------------------------
>
> Regards,
>
> Adedapo Adejumo.
> Mobile : +2348033683677
> Skype  : dapojorge
>
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