Re: Speed with Siemens DVB-S and EON

[Nenad Opsenica <nopsenica@iname.com>]

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Thomas 'Dent' Mirlacher wrote:

> On Tue, 28 Mar 2000, Nenad Opsenica wrote:
>
> >     With TechniSat card it veries from 15KB/s up to 100KB/s in one FTP
> > session, and up to 300KB/s cumulative (sum of multiple FTP sessions)
>
> hmm, my questions are:
>
> 1) what's the transponder bandwidth used for europe-online

    I really don't know that data, perhaps you should contact EON stuff and ask
them directly. Symbol rate is 22MS/s.

> 2) what's the theoretical (and pratical throughput) of the card
>         - since providers usually (if you're not using one of these who
>                 [don't] know what they're doing), have enabled slowstart
>                 on their IP stack - this is nice for terrestrial connections,
>                 ad shared media, but you can gain a lot of performance when
>                 having a single uplink station
>         - so try the thoughput measurements with a BIG file and window scaling
>                 or at least large windows enabled (your provider has to have
>                 these stuff enabled too)

    It seems (tcpdump says so!) that EON proxies are using slow-start. With
enabled large windows and SACKs on my side (EON also knows how to handle this), as
well as increased initial receive buffer size both in kernel and in Squid proxy
cache to 384KB and max. rcv. buffer size to 768K, I measured throughput which I
mentioned before - it greatly depends on every particular site and even more on
time of the day. Unfortunately, ftp throughput (of course, measured on different
file sizes, in range from 15MB up to 90MB) is not so high, even when you sum
throughputs of several ftp sessions.

    I think that you could find info on theoretical throughput of the card on
manufacturer's site.

--
Nenad Opsenica <nopsenica@iname.com>