mirror of https://github.com/tLDP/LDP
1631 lines
46 KiB
Plaintext
1631 lines
46 KiB
Plaintext
<!doctype linuxdoc system>
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<!-- LyX 1.1 created this file. For more info see http://www.lyx.org/ -->
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<article>
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<title>
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Sat (Satellite Technology) HOWTO
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</title>
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<author>
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Roberto Arcomano berto@fatamorgana.com, Florindo Santoro flosan@hack-it.net
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</author>
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<date>
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v1.81 - July 31, 2002
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</date>
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<abstract>
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Sat technology is starting to become a great resource for Internet users,
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allowing high bandwidth in downloading and many other interesting services.
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This document wants to investigate "State of Art" of Sat connections in Linux
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environment, how to get them speeder and to share with many clients. You can
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found latest version of this document at <url url="http://www.fatamorgana.com/bertolinux" name="http://www.fatamorgana.com/bertolinux"> and <url url="http://www.hack-it.net/How-To/Sat-HOWTO.html" name="http://www.hack-it.net/How-To/Sat-HOWTO.html">.
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</abstract>
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<toc>
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<sect>
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Introduction
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<sect1>
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Introduction
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<p>
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This document wants to explain something about Satellite technology, how
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it works, what do you need, configuration and how to sharing it between several
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clients. Satellite connections are very different from terrestrial ones, they
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require more attention to setup and also some more care to maintain them stable
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(snow or strong rain could prevent you to have a good signal).
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</p>
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<p>
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Feedback are welcome, don't hesitate to contact us: <url url="mailto:berto@fatamorgana.com" name="berto@fatamorgana.com"> and <url url="mailto:flosan@hack-it.net" name="flosan@hack-it.net">.
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</p>
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<sect1>
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Copyright
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<p>
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Copyright (C) 2000,2001 Roberto Arcomano, Florindo Santoro. This document
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is free; you can redistribute it and/or modify it under the terms of the GNU
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General Public License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later version. This document
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is distributed in the hope that it will be useful, but
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</p>
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<p>
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details. You can get a copy of the GNU GPL <url url="http://www.gnu.org/copyleft/gpl.html" name="here">
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</p>
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<sect1>
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Translations
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<p>
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If you want to translate this document you are free, you only have to:
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</p>
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<p>
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<enum>
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<item>
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Check that another version of it doesn't already exist at your local LDP
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<item>
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Maintain all 'Introduction' section (including 'Introduction', 'Copyright',
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'Translations', 'Credits').
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</enum>
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</p><p>
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Warning! You don't have to translate TXT or HTML file, you have to modify
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LYX file, so that it is possible to convert it all other formats (TXT, HTML,
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RIFF, etc.): to do that you can use "LyX" application you download from <url url="http://www.lyx.org" name="http://www.lyx.org">.
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</p>
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<p>
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No need to ask me to translate! You just have to let me know (if you want)
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about your translation.
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</p>
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<p>
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Thank you for your translation!
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</p>
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<sect1>
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Credits
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<p>
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Thanks to <url url="http://www.fatamorgana.com" name="Fatamorgana Computers"> for hardware equipment and experimental opportunity.
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</p>
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<p>
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Thanks to <url url="http://www.linuxdoc.org" name="Linux Documentation Project"> for publishing and uploading my document in a very quickly fashion.
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</p>
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<p>
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Thanks to Pierre Guiral and Andrei Boros for their help.
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</p>
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<sect>
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Background Knowledge
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<sect1>
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What about satellite
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<p>
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In the last few years satellite began to be applied in Internet networking,
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mainly by medium-big ISPs and we have seen it diffused between users. Sat connections
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are a very different kind of networking than terrestrial ones, with different
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timing such as higher RTT (round trip time), but also with different bandwidth
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value, up to 2 Mbps or more.
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</p>
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<sect1>
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How does it work?
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<p>
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We can imagine a path like this:
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</p>
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<p>
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<verb>
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|||||| S A T E L L I T E ||||||||
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/ /|\
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Downl / | Uploading
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load / | from
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to /(4) | (3) server
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client / |
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/ |
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SatCard(parabolic antenna) |
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| |
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\|/ |
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USER PC ----make request-----> SAT-SERVER <---retrieving---> INTERNET
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(1) (2)
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</verb>
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</p><p>
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So first we make the request (1) (using our Internet connection) to the
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Sat-Server, after it will retrieve out info from Internet (2) and it will send
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it to Satellite (3); in the end we would receive data from the it (4) to our
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home using a parabolic antenna and a Sat Card.
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</p>
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<p>
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Typically exist 2 kinds of request :
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</p>
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<p>
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<itemize>
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<item>
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Http
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<item>
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Ftp
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</itemize>
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</p><p>
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Both of them have a little request data and a much bigger answer size,
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so satellite works very well with it, but with a big time of answer, this is
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the biggest problem of satellite connection (consider a typical Sat distance,
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like 36.000 km, so you would have a time access of [ 36000 km / 300.000
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km/s = 0.120 s = ] 120 ms you have to add (2 times, cause first ISPs server
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send it to, then you download it from) to classical Internet time access.
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</p>
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<p>
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Recently ISP allows their clients to use also other kind of service, like
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</p>
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<p>
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<itemize>
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<item>
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Chat
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<item>
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Email
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<item>
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News
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</itemize>
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</p><p>
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and many others.
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</p>
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<p>
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There exist also services called "one-way", which consist in mail service
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, download on-demand (where you make a file reservation to be scheduled at
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some time) and site download: these services are offline, so you can access
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to them without modem (or other kind of) connection.
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</p>
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<sect1>
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Other technologies
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<p>
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We have to report another satellite technology: the 2-way sat connection.
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It uses only the parabolic antenna to contact Internet in both 2 directions.
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Its cost is much higher that 1-way connection. We expect something from it
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for immediate future, for now it allows a bandwidth of 4 Mbit/s in download
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and 256Kbit/s in upload.
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</p>
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<sect1>
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What is the max bandwidth?
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<p>
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It depends on many factors: ISP purpose, TCP window used, applications
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used by the client and the more important of all, "Internet congestion".
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</p>
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<p>
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You can expect a max bandwidth of 1-4 Mbps and a average of about 10-30
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KBytes/s, but I repeat, it depends on many factors.
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</p>
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<p>
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Anyway some ISPs tell you they give you a "Max" bandwidth, while the average
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bandwidth could be very lower, due to intra-ISP congestion.
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</p>
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<p>
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Some other ISPs guarantees you to have a "Minimal" bandwidth, which is more
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meaningful than "MAX", cause it is available all the time.
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</p>
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<p>
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Please see Appendix A for more about get downloading performance better.
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</p>
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<sect1>
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How much does it cost?
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<p>
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We have to distinguish between hardware costs and account costs, the first
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are known, while the second depend on which service you choose ("guaranteed"/"not
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guaranteed", what bandwidth).
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</p>
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<sect2>
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Hardware costs
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<p>
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To install our little satellite system we need:
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</p>
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<p>
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<enum>
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<item>
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Sat card
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<item>
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Parabolic antenna
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<item>
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one or more feed (converter)
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</enum>
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</p><p>
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Noticed that we need a digital converter to use Internet via satellite.
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</p>
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<p>
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Sat card costs depends on brand you choose, about 200US$-300US$.
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</p>
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<p>
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Parabolic antenna is about 50 US$.
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</p>
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<p>
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Converter is about 50US$.
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</p>
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<p>
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So we have about 3-400 US$ of hardware cost (maybe you still have
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to add installation cost!!).
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</p>
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<p>
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If you want also receiver Crypt service:
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</p>
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<p>
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<enum>
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<item>
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CI is about 100 US$.
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<item>
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CAM is about 100 US$-250 US$.
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</enum>
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</p><sect2>
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Account costs
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<p>
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Here costs depend on what ISPs give you access, what's peak bandwidth,
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if there is a guaranteed bandwidth (which is more important than peak one),
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what kind of service they give you and so on.
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</p>
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<p>
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Also some ISP gives you free access in change of viewing an always foreground
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spot banner (you cannot iconize it!!): in this case you will pay when you'll
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go to buy something showed in banner!!
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</p>
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<p>
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Typically account costs are about 100-150 US$ at year for "not guaranteed"
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services and 4-600 US$ or more for guaranteed ones (they guarantee you
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a minimal bandwidth you can use also under congestion moments, obviously intra
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Sat-ISP congestion!! When you go out to Internet nobody can guarantee you anything!!).
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</p>
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<sect1>
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What are the satellites used?
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<p>
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When we speak about satellites we mean: Astra (19.2 degree SE), Hotbird
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(13.2 degree SE), new Europestar (45 degree SE), Eutelsat (8 degree SW), Astra
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(26E), ArabSat 3A (26E).
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</p>
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<sect1>
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What ISPs give Sat Internet Access?
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<p>
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In Europe we know about 8 ISPs giving Sat access for Internet:
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</p>
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<p>
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<enum>
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<item>
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<url url="http://www.europeonline.net" name="EuropeOnLine - EON">
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<item>
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<url url="http://www.netsystem.com" name="Netsystem">
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<item>
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<url url="http://www.starspeeder.com" name="Starspeeder">
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<item>
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<url url="http://www.satnode.com" name="Sat Node">
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<item>
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<url url="http://www.eliosat.com" name="Eliosat">
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<item>
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<url url="http://www.falconstream.com" name="Falcon Stream ">
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<item>
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<url url="http://www.skydsl.com" name="SkyDSL">
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<item>
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<url url="http://www.opensky.it" name="OpenSky">
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<item>
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<url url="http://www.direcpc.com" name="DirecPC"> but this use a proprietary sat card (this is a first Sat ISP )
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<item>
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<url url="http://www.xanticbroadband.com/" name="http://www.xanticbroadband.com/">
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</enum>
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</p><p>
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EON gives access for about 150 US$ at year without guaranteed bandwidth.
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</p>
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<p>
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Netsystem offers its services at "null cost", you just have to see its banner.
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</p>
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<p>
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Starspeeder gives access ???
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</p>
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<p>
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Eliosat costs 350 US$ at year with a 128 Kbps guaranteed (minimal
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service, see web site for more);in addition it gives 2-way technology access
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for either receive and transmit.
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</p>
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<p>
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SkyDSL gives access full-time and it costs about 15 US$ at month
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with 128Kbit/s bandwidth, but it allows a bigger bandwidth where you pay each
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Mb downloaded (you can select from 256Kbit/s up to 4Mbit/s), for more you can
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visit its web site.
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</p>
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<p>
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IMPORTANT : before subscribing some satellite account, please verify "foot
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of Satellite" and diameter of parabola.
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</p>
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<p>
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OpenSky started before summer 2001 in its "beta test": it allows you to try
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the sat service downloading at maximum 300 MB at month (free). To register
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you need to go at <url url="http://www.opensky.it/cc/index.asp?f=registrazione.htm" name="OpenSky registration procedure"> (which is in italian language!).
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</p>
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<sect1>
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What else?
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<p>
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With every kind of DVB card you can also receive TV digital channels (free
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channels only) and some cards have support for common interface to watch encrypted
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channel.
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</p>
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<p>
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Follows the schema:
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</p>
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<p>
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<verb>
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Smart-Card -> CAM -> Common Interface -> Sat Card (with support C.I.)
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</verb>
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</p><p>
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CAM Card (there are many standards used for decryption: SECA, IRDETO, VIACCESS
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and others) is the hardware allowing decryption (for TV, Radio and Data) while
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the Common Interface or C.I. (ETSI EN 50221) allow connection between CAM and
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Sat Card.
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</p>
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<sect>
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Technical Information
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<sect1>
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General working
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<p>
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We now try to understand how satellite connection works and at what conditions.
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</p>
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<p>
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We can imagine a satellite link as a classical Wireless link, I mean a
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link between 2 systems which don't use a real cable to talk each other.
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</p>
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<p>
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Wireless link is very different from Wired link cause we have some additional
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problems to solve, such as reachability, privacy problems and so on. Also there
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could be weather problems, particularly in snow or rain conditions.
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</p>
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<p>
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Anyway, we have to consider the first principle behind Wireless communication:
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line of sight free, which is a MUST unless we are unable to talk. For more
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you can see the <url url="http://www.fatamorgana.com/bertolinux/" name="Wireless-HOWTO">.
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</p>
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<p>
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In sat connections we use a special kind of antenna, a parabolic one, that
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gives us a very high gain in RX, needed to receive satellite signal: in fact
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satellite has a geostational orbital at 36.000 km and the only kind of antenna
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we can use for receiving is just a parabolic one.
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</p>
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<sect1>
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Frequencies
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<p>
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Frequency we receive is from 11GHz up to 12.7 GHz (from the satellite transponder,
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the transmitter sending us datas), a very high freq., but the feed (converter
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in the center of the parabola) converts it to, in output, 1-2 GHz so that we'll
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able to send signal to the receiver through the cable (up to 40m depending
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to cable loss).
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</p>
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<sect1>
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DVB Receiver Card
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<p>
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<verb>
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1 GHz Signal --> |RX|--> |ADC| --> |Low Level Network| --> |O.S. TCP/IP Stack|--> Data
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|____________________________________|
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DVB Card
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</verb>
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</p><p>
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Now we can imagine a classical RX at 1 GHz receiving analog signals from
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the Sat, converting it to digital signals and giving all to the low level network
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layer (ISO OSI 1,2): here, card firmware builds a 2 level packet (pretty like
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ethernet) to be sent to our PC with Linux, Windows, or other system, and in
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the end, we will only have to transform it to a TCP/IP packet.
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</p>
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<sect1>
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Data Link Level DVB setting
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<p>
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Here we have to config some settings, directly to the DVB card:
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</p>
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<p>
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<enum>
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<item>
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Frequency working, we have to set the satellite frequency (as from magazines):
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it is between 11.8 GHz and 12.8 GHz for example 12640000 KHz
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<item>
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Symbol rate, measured in symbols per seconds, typically 22 MS/s (Mega Symbols
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per seconds)
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<item>
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Polarization, which is an antenna setting configurable in software: possible
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values are H (Horizontal) or V (Vertical).
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<item>
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PIDs. The PID is used for select a trasmission between many signal from
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same frequency.
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<item>
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Also we have to specify the bitfilter mask, which tells us how large is
|
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the destination MAC addresses group (bitfilter mask is similar to TCP/IP netmask,
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the only difference is that the bitfilter mask is 48 bit size while TCP/IP
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netmask is 32 bit size). Always Internet data is sent with Unicast PID, while
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Video always is sent using Multicast PID .
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<item>
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Calculate MAC address: here we specify what will be our MAC address (for
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our DVB card). You need to do this cause some ISP uses an algorithm (see Appendix
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A for more) which calculates your MAC address from your IP address, some other
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ISP uses your own MAC address.
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</enum>
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</p><sect1>
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|
TCP/IP working
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<p>
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As we said in 2.2 section, first we have to make a request using the modem
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interface (i.e. ppp0 or whatever we use to reach Internet), then the answer
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will return to our DVB interface (dvb0).
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</p>
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<p>
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Modern O.S. allow us to receive packets from an input interface, different
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from the output interface from where we made the request: to do it we have
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to "disable" some packets flow control, such as type an
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|
</p>
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<p>
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echo "0" > /proc/sys/net/ipv4/conf/dvb0/rp_filter (for Linux).
|
|
</p>
|
|
<sect1>
|
|
Authentication
|
|
<p>
|
|
It remains only one thing to complete our description: authentication method.
|
|
</p>
|
|
<p>
|
|
Some Sat ISPs use the so called "Proxy Authentication": when you used their
|
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proxy, you also need to give login and password to continue the request (you
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|
should have been subscribed some kind of account to use their sat service):
|
|
once done, the ISP use your IP address to calculate your MAC address (see Appendix
|
|
A for more), to which send the answer.
|
|
</p>
|
|
<p>
|
|
Some other ISPs require you make a VPN connection (using your login and
|
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password) first, then they will control your registration account (where they
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retrieve your MAC address) and will send data directly to (and only to) your
|
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card (your MAC address).
|
|
</p>
|
|
<p>
|
|
Anyway noticed that you can modify your dvb sat filter value to be able
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|
to receive packets destined to EVERY mac address (related to a single frequency).
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|
</p>
|
|
<sect1>
|
|
Services I can use with a sat connection
|
|
<p>
|
|
Typically services you can have from sat connections depend on what authentication
|
|
system is used by ISP:
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
with classical "Proxy Authentication" you can only use HTTP and FTP service,
|
|
while
|
|
<item>
|
|
with VPN connection you have (ideally) no limit to services you can use,
|
|
the only limit is decided by RTT (time access) to satellite, about 500-1000
|
|
ms average: so you can forget to use "Voice" or other "Real Time" services!! (see
|
|
<url url="http://www.fatamorgana.com/bertolinux" name="VoIP-HOWTO"> for more). Anyway you still can use: mail, chat, telnet, ping, dns and so
|
|
on.
|
|
</itemize>
|
|
</p><sect>
|
|
Requirements
|
|
<p>
|
|
Here we will see what we need to try a Sat system.
|
|
</p>
|
|
<sect1>
|
|
Knowledge requirement
|
|
<p>
|
|
For this trying you need some experience in internetworking under Linux
|
|
(as from <url url="http://www.linuxdoc.org/HOWTO/Net-HOWTO/index.html" name="Net-HOWTO">) and a very little of practical experience with parabolic antenna
|
|
and sat systems (you should be able to pointing out your antenna, with right
|
|
angles).
|
|
</p>
|
|
<sect1>
|
|
Hardware
|
|
<p>
|
|
We need:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
Parabolic antenna, also taken from an analog system.
|
|
<item>
|
|
Digital converter to be placed in the middle of the antenna.
|
|
<item>
|
|
Receiver card DVB compatible.
|
|
<item>
|
|
a PC to connect to.
|
|
</enum>
|
|
</p><sect1>
|
|
Software
|
|
<p>
|
|
Here you need a
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
driver for the DVB card working under your O.S. (Linux, Windows or other).
|
|
<item>
|
|
right setting to use it
|
|
<item>
|
|
external application in some cases (such as VPN-PPTP client for ISP like
|
|
Netsystem or Starspeeder).
|
|
</enum>
|
|
</p><p>
|
|
For the software under Linux you can found the Siemens DVB driver at <url url="http://www.linuxtv.org" name="Linux TV Project">.
|
|
</p>
|
|
<sect1>
|
|
TV Software
|
|
<p>
|
|
There is also some Video software used to implement TV reception:
|
|
</p>
|
|
<sect2>
|
|
Under Windows
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
MultiDec <url url="http://www.erkner.com/free/digi/MultiDec66b.zip" name="MultiDec 6.6b"> (free with source code)
|
|
<item>
|
|
TPREdit <url url="http://come.to/uhura" name="TPREdit"> (for Technotrend)
|
|
<item>
|
|
WinTV DVBs <url url="http://www.hauppauge.de/software.htm" name="Hauppauge"> or <url url="http://www.technotrend.de" name="Technotrend">(for Siemens compatible card, Hauppauge, Technotrend, Technisat,
|
|
etc... )
|
|
<item>
|
|
WinDVB2000 <url url="http://www.odsoft.org/english.html" name="WinDVB2000"> (about 19$).
|
|
</enum>
|
|
</p><sect2>
|
|
Under Linux
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
gVideo is an application included in Siemens driver
|
|
<item>
|
|
Vdr Video Recoder (good for watch TV)
|
|
</enum>
|
|
</p><sect>
|
|
Base setup
|
|
<sect1>
|
|
First: mounting
|
|
<p>
|
|
The first thing we have to do is to mount our parabolic antenna;
|
|
</p>
|
|
<p>
|
|
After we need to pointing it out (searching right degrees from some magazine):
|
|
degrees are always intended from south to east or to west for horizontal one
|
|
and from ground to satellite line for vertical one. Classical pointing tools
|
|
is the compass.
|
|
</p>
|
|
<sect1>
|
|
Calibrating
|
|
<p>
|
|
How can we see if we are right oriented?
|
|
</p>
|
|
<p>
|
|
After decided a right range of angles, we have to adjust it measuring power
|
|
level. For such a thing we can
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
Use for example an analog receiver (which is compatible with digital converter)
|
|
and start to search right degree: when we see some imagine we'll get it. I
|
|
suggest to use analog converter cause, maybe, you have one (from precedent
|
|
installation) and cause it is more simple to calibrate it than digital one.
|
|
<item>
|
|
Use a power meter (about 20US$) with sequential lights: at full
|
|
signal all lights turn up.
|
|
</enum>
|
|
</p><sect1>
|
|
Double Feed
|
|
<p>
|
|
You can also install a double feed system (some vendors sell a complete
|
|
kit with standard distance to receive, for example, Astra (19.2 SE) with Eutelsat
|
|
(16 SE) or with HotBird (13 SE).
|
|
</p>
|
|
<p>
|
|
For mounting it you have to consider, in addition, that satellite is at
|
|
the opposite side of the converter, like in figure:
|
|
</p>
|
|
<p>
|
|
<verb>
|
|
SAT1 SAT2
|
|
\ /
|
|
\ /
|
|
\ C1 C2 /
|
|
\ \ \ / / /
|
|
\ \ / \ / /
|
|
\____\ /___\ /_____/
|
|
|
|
Top View
|
|
|
|
C1 receives from SAT2
|
|
C2 receives from SAT1
|
|
</verb>
|
|
</p><p>
|
|
Also, with 2 focus, you would use a diseq.
|
|
</p>
|
|
<sect1>
|
|
Data-link level adjusting
|
|
<p>
|
|
Once we got analog signal we have to adjust our receiver to right frequency,
|
|
PID, speed rate and so on.
|
|
</p>
|
|
<p>
|
|
I report here an example of configuration, for EON (EuropeOnLine), transponder
|
|
114 on Astra satellite (19.2 SE)
|
|
</p>
|
|
<p>
|
|
Frequency: 12640 MHz
|
|
</p>
|
|
<p>
|
|
Polarization: V (Vertical)
|
|
</p>
|
|
<p>
|
|
Symbol Rate: 22000 KS/s
|
|
</p>
|
|
<p>
|
|
PIDs:
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Unicast: 512 (decimal), 0x200 (hexadecimal)
|
|
<item>
|
|
Multicast: 785, 786, 1041 (decimal), 0x311, 0x312, 0x411 (hexadecimal),
|
|
but you should notice that, in many cases, Multicast PIDs are taken in automatic.
|
|
</itemize>
|
|
</p><p>
|
|
We also need another info: what MAC address to assign to our DVB card.
|
|
|
|
</p>
|
|
<p>
|
|
Again, for EON you can see Appendix A to calculate MAC address from dynamic
|
|
IP address.
|
|
</p>
|
|
<p>
|
|
Obviously you need login and password to use ISP service.
|
|
</p>
|
|
<sect>
|
|
Configuration under Linux
|
|
<p>
|
|
In this section I will assume to use a Siemens compatible card, like an
|
|
Hauppage WinTV DVB card, for such cards you can download drivers from <url url="http://www.linuxtv.org/download/dvb" name="LinuxTV"> or <url url="http://www2.arnes.si/~mthale1/index.html " name="DVB-s PCI cards under Linux">.
|
|
</p>
|
|
<p>
|
|
Unfortunately there are no drivers (at this moment) for SkyStar2 (Netsystem
|
|
card) for Linux!
|
|
</p>
|
|
<sect1>
|
|
Drivers installation
|
|
<p>
|
|
Once downloaded drivers, you have to untar them to a directory, enter it
|
|
and type "make" and "make insmod". To do this you need to have actual kernel sources
|
|
under /usr/src/linux (unless, download them from <url url="http://www.kernel.org" name="http://www.kernel.org"> and recompile them).
|
|
</p>
|
|
<p>
|
|
After made "make insmod", your system should have DVB modules loaded. To
|
|
unload them type simply "make rmmod".
|
|
</p>
|
|
<sect1>
|
|
Setting up /etc/dvbd.conf
|
|
<p>
|
|
/etc/dvbd.conf file is used to setup data-link parameters for your DVB
|
|
card. Here main settings:
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
"power", which indicates the power to LNB, 1=ON, 0=OFF. Usually you should
|
|
set it to 1, unless you do some kind of cascade between more than 1 LNB.
|
|
<item>
|
|
"symbolrate", this is the symbol rate per seconds, for example 22.000.000.
|
|
<item>
|
|
"frequency", at which receiving datas, like 12.640.000.
|
|
<item>
|
|
"ttk", the 22 kHz signal, almost always to 1.
|
|
<item>
|
|
"diseqc", used to control the diseq, (it means only when you have a diseq
|
|
controlling 2 or more converters) 0 if none.
|
|
<item>
|
|
"AFC", usually set to 1.
|
|
<item>
|
|
"polarization", 1 for horizontal or 0 for vertical one.
|
|
<item>
|
|
"filter_n <PID> <MAC> <BITFILTER>", where n is intended
|
|
0 for Unicast and 1-9 for Multicast; PID is expressed in decimal form, MAC
|
|
is the MAC address only valid for Multicast filter and BITFILTER is a number
|
|
which bits represent bytes to mask (for example 10 = 2 (bit 1) + 8 (bit 3),
|
|
so mask will be 00 00 FF 00 FF 00).
|
|
</itemize>
|
|
<p>
|
|
<quote>
|
|
Example
|
|
</quote>
|
|
</p><p>
|
|
------------------------------------------
|
|
</p>
|
|
<p>
|
|
# DVB receiver configuration file, (c) 2000 data planet international
|
|
</p>
|
|
<p>
|
|
# standard location in /etc
|
|
</p>
|
|
<p>
|
|
# LNB power on=1/off=0
|
|
</p>
|
|
<p>
|
|
power 1
|
|
</p>
|
|
<p>
|
|
# symbol rate [symbol/sec]
|
|
</p>
|
|
<p>
|
|
symbolrate 22000000
|
|
</p>
|
|
<p>
|
|
# ASTRA TR 114
|
|
</p>
|
|
<p>
|
|
frequency 12640000
|
|
</p>
|
|
<p>
|
|
# 22 kHz signal on=1/off=0
|
|
</p>
|
|
<p>
|
|
ttk 1
|
|
</p>
|
|
<p>
|
|
# diseqc on=1/off=0
|
|
</p>
|
|
<p>
|
|
diseqc 0
|
|
</p>
|
|
<p>
|
|
# AFC on=1/off=0
|
|
</p>
|
|
<p>
|
|
AFC 1
|
|
</p>
|
|
<p>
|
|
# polarisation H=1/V=0
|
|
</p>
|
|
<p>
|
|
polarisation 1
|
|
</p>
|
|
<p>
|
|
# settings for MPE filter, PID and MAC filtering, valid MAC bytes
|
|
</p>
|
|
<p>
|
|
filter_0 512
|
|
</p>
|
|
<p>
|
|
filter_1 785 00:D0:5C:1E:96:01 48
|
|
</p>
|
|
<p>
|
|
filter_2 786 00:D0:5C:1E:96:01 48
|
|
</p>
|
|
<p>
|
|
filter_3 1041 00:D0:5C:1E:96:01 48
|
|
</p>
|
|
<p>
|
|
-----------------------------------------
|
|
</p>
|
|
<p>
|
|
filter_0 has no MAC and no bitfilter values cause the right MAC address
|
|
is calculated from IP address (see Appendix A). We will see this setting is
|
|
OK only for some ISP, for others we'll have to change dvbd.c
|
|
</p>
|
|
<sect1>
|
|
Dvbd daemon
|
|
<p>
|
|
Once your /etc/dvbd.conf is ok, you can launch dvbd application, which,
|
|
if executed without -d option, write to stdout signal quality level:
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Sync MUST be 127 or near it
|
|
<item>
|
|
Vber MUST be 0
|
|
</itemize>
|
|
</p><p>
|
|
unless you are not well receiving from Sat (check cable and/or dish pointing).
|
|
</p>
|
|
<p>
|
|
Note:
|
|
</p>
|
|
<p>
|
|
Maybe you have to change, in dvbd.h this line
|
|
</p>
|
|
<p>
|
|
#define network_device "eth0"
|
|
</p>
|
|
<p>
|
|
to
|
|
</p>
|
|
<p>
|
|
#define network_device "ppp0"
|
|
</p>
|
|
<p>
|
|
depending on which interface you use to reach Internet, eth0 or ppp0: type
|
|
"make" to update binary file and restart dvbd.
|
|
</p>
|
|
<sect1>
|
|
How to config EON service
|
|
<p>
|
|
Now you have a good signal, you can try to use some sat service.
|
|
</p>
|
|
<p>
|
|
For EON go at "proxy" setting in Netscape preferences and set under HTTP
|
|
and FTP:
|
|
</p>
|
|
<p>
|
|
proxy.xxx.europeonline.net
|
|
</p>
|
|
<p>
|
|
and, in "port" 8080 and FTP proxy with "port" 8090.
|
|
</p>
|
|
<p>
|
|
where xxx is the transponder number (103,113,114 or 115) you are using
|
|
(see Appendix B for more).
|
|
</p>
|
|
<p>
|
|
Now you should be able to navigate wherever you want.... Good navigation.
|
|
</p>
|
|
<p>
|
|
To share EON service with many clients you can use <url url="http://www.squid-cache.org" name="Squid proxy"> application, enabling
|
|
cascade to EON proxy.
|
|
</p>
|
|
<p>
|
|
For a more complex use of EON, like more complex cascade proxy or sharing
|
|
users, see <url url="http://obiwan.hvrlab.org/~faz/eon/eon_masq.html" name="EON Linux Masquering FAQ Page">
|
|
</p>
|
|
<sect1>
|
|
How to use Netsystem service
|
|
<p>
|
|
Netsystem service is a little more complicated than EON under Linux, cause,
|
|
in addition, you need to setup:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
VPN connection
|
|
<item>
|
|
patch for pppd (needed only if using pppd <= 2.4.0)
|
|
<item>
|
|
routing settings with simple scripts
|
|
<item>
|
|
patch for dvbd.c
|
|
<item>
|
|
Test it
|
|
<item>
|
|
Get performance better
|
|
<item>
|
|
Sharing Netsystem with many clients
|
|
</enum>
|
|
</p><sect2>
|
|
VPN connection
|
|
<p>
|
|
First you need to download <url url="http://cag.lcs.mit.edu/~cananian/Projects/PPTP/" name="VPN PPTP client application">.
|
|
</p>
|
|
<p>
|
|
After untared, compiled and installed it, you should add an entry to your
|
|
/etc/ppp/pap-secrets and /etc/ppp/chap-secrets files, like that:
|
|
</p>
|
|
<p>
|
|
"login" * "password" *
|
|
</p>
|
|
<p>
|
|
where "login" and "password" are the same according to <url url="http://css.netsystem.com" name="Netsystem registration">.
|
|
</p>
|
|
<sect2>
|
|
Patch for pppd
|
|
<p>
|
|
As described at <url url="http://www.sigpipe.org/~me/vpn/pptp.html" name="PPTP description">, you need to patch your pppd daemon to support connection
|
|
with Netsystem VPN server (Linux server).
|
|
</p>
|
|
<p>
|
|
Warning: using pppd version >= 2.4.0 you don't need pppd patch.
|
|
</p>
|
|
<p>
|
|
So you have to:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
download a <url url="ftp://cs.anu.edu.au/pub/software/ppp/" name="recent pppd version">
|
|
<item>
|
|
download and gunzip the correspondent patch for pppd from <url url="ftp://ftp.binarix.com/pub/ppp-mppe/" name="Here">
|
|
<item>
|
|
untar pppd in a directory
|
|
<item>
|
|
type "patch -p0 < patch_name"
|
|
<item>
|
|
enter pppd directory
|
|
<item>
|
|
type "make", "make install"
|
|
</enum>
|
|
</p><sect2>
|
|
Routing settings
|
|
<p>
|
|
Now your pppd will be able to working with:
|
|
</p>
|
|
<p>
|
|
"pptp vpn.netsystem.com debug user <login>"
|
|
</p>
|
|
<p>
|
|
where <login> is your login account from Netsystem: you should see,
|
|
in log file (/var/log/messages) ppp1 connection debug info.
|
|
</p>
|
|
<p>
|
|
If all is ok you should see ppp1 interface with "ifconfig" command.
|
|
</p>
|
|
<p>
|
|
If you still have problems on authentication, please add a "noauth" line
|
|
to your /etc/ppp/options file.
|
|
</p>
|
|
<p>
|
|
Once ppp1 interface is up, you should do the following:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
type "ifconfig ppp1" and find the IP address (I will call IP) on the right
|
|
of "P-t-P:" string.
|
|
<item>
|
|
delete it from routing table with "route del IP"
|
|
<item>
|
|
add it to ppp0 interface with "route add IP dev ppp0"
|
|
<item>
|
|
delete default gateway from ppp0 with "route del default"
|
|
<item>
|
|
add default gateway to ppp1 with "route add default dev ppp1"
|
|
</enum>
|
|
</p><p>
|
|
Points 1-3 are requested cause point-to-point interface are managed, under
|
|
Linux, adding the gateway to the new interface (which is not a good idea in
|
|
this case): unless it you will have a endless loop, cause your packet will
|
|
be continuously encapsulated on itself.
|
|
</p>
|
|
<p>
|
|
Points 4,5 are used to make "all internet requests" to ppp1 interface, so
|
|
we'll reach the "world" by using VPN connection: this could be not optimal in
|
|
some condition, for example for DNS queries, which could be sent directly to
|
|
avoid useless Sat delay time.
|
|
</p>
|
|
<p>
|
|
Instead of manually setup routing configuration you can try using these
|
|
little scripts:
|
|
</p>
|
|
<p>
|
|
"netsystem.on" script
|
|
</p>
|
|
<p>
|
|
______________________________________________________________________
|
|
|
|
</p>
|
|
<p>
|
|
route add IP_DNS1 dev ppp0
|
|
</p>
|
|
<p>
|
|
route add IP_DNS2 dev ppp0
|
|
</p>
|
|
<p>
|
|
route add -net 212.31.242.0 netmask 255.255.255.0 dev ppp0
|
|
</p>
|
|
<p>
|
|
pptp vpn.netsystem.com user <login>
|
|
</p>
|
|
<p>
|
|
/bin/sleep 5
|
|
</p>
|
|
<p>
|
|
route add default dev ppp1
|
|
</p>
|
|
<p>
|
|
______________________________________________________________________
|
|
|
|
</p>
|
|
<p>
|
|
"netsystem.off" script
|
|
</p>
|
|
<p>
|
|
______________________________________________________________________
|
|
|
|
</p>
|
|
<p>
|
|
route del IP_DNS1 dev ppp0
|
|
</p>
|
|
<p>
|
|
route del IP_DNS2 dev ppp0
|
|
</p>
|
|
<p>
|
|
route del -net 212.31.242.0 netmask 255.255.255.0 dev ppp0
|
|
</p>
|
|
<p>
|
|
kill -9 `ps x|grep "pppd"|grep "<login>"|grep
|
|
-v "ps"|tr " " "\n"|head -n 2`
|
|
</p>
|
|
<p>
|
|
rm --force /var/lock/LCK..tty*
|
|
</p>
|
|
<p>
|
|
rm --force /var/run/pptp/*
|
|
</p>
|
|
<p>
|
|
rm --force /var/run/ppp1.pid
|
|
</p>
|
|
<p>
|
|
killall -9 pptp
|
|
</p>
|
|
<p>
|
|
______________________________________________________________________
|
|
|
|
</p>
|
|
<p>
|
|
IP_DNS1 and IP_DNS2 are ip addresses of your dns servers (primary and secondary).
|
|
|
|
</p>
|
|
<p>
|
|
<login> is the login name of your Netsystem account.
|
|
</p>
|
|
<p>
|
|
I tried it out under kernel 2.4.6 RedHat 7.1 and it works very well (without
|
|
any problems about ppp1 endless loop or similar).
|
|
</p>
|
|
<p>
|
|
This line:
|
|
</p>
|
|
<p>
|
|
kill -9 `ps x|grep "pppd"|grep "<login>"|grep
|
|
-v "ps"|tr " " "\n"|head -n 2`
|
|
</p>
|
|
<p>
|
|
is used to find PID of pppd process talking with VPN server (ppp1 interface):
|
|
notice that you cannot just only type " killall pppd" cause your
|
|
ppp0 interface also would go down.
|
|
</p>
|
|
<sect2>
|
|
Patch for dvbd.c
|
|
<p>
|
|
After solved problems about PPTP you have to change some line in dvbd.c,
|
|
near the end of it:
|
|
</p>
|
|
<p>
|
|
<verb>
|
|
if (strcmp (v, "filter_0") == 0) { if (s != NULL) { unsigned char ip[4];
|
|
dvbcfg[0].status = ON ;
|
|
dvbcfg[0].filter.data[0] = 0x3eff ;
|
|
dvbcfg[0].filter.pid = (__u16) atoi (s) ;
|
|
dvbcfg[0].filter.mode = 0x0c ;
|
|
if (ipget (ip, network_device)) { fprintf(stderr,"Can't get local ip address. Stop.\n") ; return -1 ; }
|
|
syslog (LOG_NOTICE, "Local ip is %u:%u:%u:%u\n", ip[0], ip[1], ip[2], ip[3]);
|
|
dvbcfg[0].filter.data[1] = (ip[3] << 8) | 0x00ff ;
|
|
dvbcfg[0].filter.data[2] = (ip[2] << 8) | 0x00ff ;
|
|
dvbcfg[0].filter.data[6] = (ip[1] << 8) | 0x00ff ;
|
|
dvbcfg[0].filter.data[7] = (ip[0] << 8) | 0x00ff ;
|
|
dvbcfg[0].filter.data[8] = (0x02 << 8) | 0x00ff ;
|
|
dvbcfg[0].filter.data[9] = (0x00 << 8) | 0x00ff ;
|
|
setmac (ip) ; }
|
|
else { dvbcfg[1].status = OFF ; } }
|
|
</verb>
|
|
<p>
|
|
<quote>
|
|
Now following lines:
|
|
</quote>
|
|
</p><p>
|
|
dvbcfg[0].filter.data[1] = (ip[3] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[2] = (ip[2] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[6] = (ip[1] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[7] = (ip[0] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[8] = (0x02 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[9] = (0x00 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
<quote>
|
|
will be changed to
|
|
</quote>
|
|
</p><p>
|
|
dvbcfg[0].filter.data[1] = (MAC[5] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[2] = (MAC[4] <<
|
|
8) | 0x00ff;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[6] = (MAC[3] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[7] = (MAC[2] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[8] = (MAC[1] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[9] = (MAC[0] <<
|
|
8) | 0x00ff ;
|
|
</p>
|
|
<p>
|
|
Where MAC[0]:MAC[1]:MAC[2]:MAC[3]:MAC[4]:MAC[5]
|
|
is our MAC address (according to Netsystem registration).
|
|
</p>
|
|
<p>
|
|
For example, using the address 00:d0:d0:d0:d0:d0 we'll have:
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[1] = (0xd0 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[2] = (0xd0 << 8) | 0x00ff;
|
|
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[6] = (0xd0 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[7] = (0xd0 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[8] = (0xd0 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
dvbcfg[0].filter.data[9] = (0x00 << 8) | 0x00ff
|
|
;
|
|
</p>
|
|
<p>
|
|
notice hexadecimal notation 0x??
|
|
</p>
|
|
<p>
|
|
After, you have to type "make" and use the new dvbd created.
|
|
</p>
|
|
<p>
|
|
Note: to successfully patch the dvbd.c you need to use dvb driver version
|
|
>= 0.8.2, cause older versions have some instability problems.
|
|
</p>
|
|
<sect2>
|
|
Test it
|
|
<p>
|
|
Finally, we can test Netsystem under Linux. We can make a "ping www.somehostpingable.com"
|
|
and check the response time: it should be between 400 and 2000 ms.
|
|
</p>
|
|
<p>
|
|
If you still have problems, you should control if all is OK with VPN interface:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
open your preferred network sniffer (for example <url url="http://www.ethereal.net" name="Ethereal">) and starts to analyze
|
|
"ppp0" interface (ppp0, not ppp1!!)
|
|
<item>
|
|
make a ping
|
|
</enum>
|
|
</p><p>
|
|
If VPN is ok you should see 2 (or maybe 1) GRE-Encapsulated packets each
|
|
second, endless. If you cannot view anything your VPN is not correctly working:
|
|
stop it and restart it.
|
|
</p>
|
|
<sect2>
|
|
Get performance better
|
|
<p>
|
|
Once you setup all things you NEED to use (particularly with Netsystem
|
|
service) some "download accelerator" to get performance better: please see Appendix
|
|
A for more.
|
|
</p>
|
|
<sect2>
|
|
Sharing Netsystem with many clients
|
|
<p>
|
|
To do this you can enable "IP Masquering", allowing your client to use VPN
|
|
like a normal Internet interface; main problem is that our satellite connection
|
|
is very good for download while it has bad performance for just browsing web
|
|
pages (or other service more interactive than downloading).
|
|
</p>
|
|
<p>
|
|
You can think to use <url url="http://www.squid-cache.org" name="Squid proxy"> or <url url="http://www.socks.nec.com/" name="Socks proxy">, but you don't solve your problems, cause even
|
|
now ALL your request would be forwarded to same interface, VPN.
|
|
</p>
|
|
<p>
|
|
The solution is to use 2 routing tables, one using direct line interface
|
|
and the other using VPN one. So you can do like this:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
be sure of have installed "iproute2" commands (for example type "ip" on shell
|
|
and control if it tells you something), for more see <url url="http://www.linuxdoc.org/HOWTO/Adv-Routing-HOWTO.html" name="Linux 2.4 Advanced Routing HOWTO">.
|
|
<item>
|
|
be sure of have started Netsystem service and annotate ppp1 interface IP
|
|
address, we'll call it LOCALIP.
|
|
<item>
|
|
type: "echo "210 sat" >> /etc/iproute2/rt_tables", to more comfortable
|
|
call "sat" rule 210
|
|
<item>
|
|
type: "ip rule add from LOCALIP table sat", to create table "sat" relative
|
|
to all requests coming from LOCALIP IP address.
|
|
<item>
|
|
type: "ip route add default dev ppp1 table sat", to send all "sat" requests
|
|
(see above) to ppp1 interface.
|
|
<item>
|
|
if you use <url url="http://www.socks.nec.com/" name="Socks proxy"> be sure to set, in sockd.conf file, "external" to LOCALIP.
|
|
<item>
|
|
if you use <url url="http://www.squid-cache.org" name="Squid proxy"> be sure to set, in squid.conf file, "tcp_outgoing_address" to
|
|
LOCALIP.
|
|
</enum>
|
|
</p><p>
|
|
Once done all that, you will notice to have 2 kind of working: without
|
|
any proxy your clients will ask to direct line, while by using proxy (squid
|
|
or sockd) the request will be forwarded to VPN interface and, definitely, toward
|
|
satellite.
|
|
</p>
|
|
<p>
|
|
Notice that maybe you wish to use sockd instead of squid, cause satellite
|
|
requests are typically used for download (while squid is typically used for
|
|
browsing...).
|
|
</p>
|
|
<p>
|
|
What happens with iproute2 commands is that, when you ask for an address
|
|
to sockd or squid, relative proxy (using IPLOCAL IP address, bound at run-time
|
|
by proxy network daemon) request enters the TCP/IP stack where kernel will
|
|
forward it (thanks to point 4 above) to sat table and, definitely (by using
|
|
point 5) to ppp1 interface. All other rules will be forwarded to classical
|
|
default route (I mean across ppp0 interface or whatever other interface for
|
|
direct Internet).
|
|
</p>
|
|
<sect1>
|
|
How to use Sat Node service
|
|
<p>
|
|
You have to follow all instructions as for Netsystem.
|
|
</p>
|
|
<p>
|
|
Before enabling VPN connection, you need to type:
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
''route del default'', we delete default route
|
|
<item>
|
|
''route add 212.56.224.36 dev ppp0'', we tell it that it has to reach the
|
|
vpn server just through ppp0
|
|
<item>
|
|
''pptp 212.56.224.36 user user-name'', we create VPN
|
|
<item>
|
|
''route add default dev ppp1'', we tell it that it must use this route
|
|
to reach every place.
|
|
</itemize>
|
|
</p><p>
|
|
What really changes from Netsystem is that, we don't force VPN gateway
|
|
(212.56.224.34, IP on the right of ''P-t-P'' in ppp1 interface) on ppp0 interface,
|
|
but we force another IP (212.56.224.36). All other things should not change.
|
|
</p>
|
|
<p>
|
|
Thanks to Ricardo Santiago Mozos and Norberto Garcia Prieto.
|
|
</p>
|
|
<sect1>
|
|
OpenSky service under Linux
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
You need to register at <url url="http://www.opensky.it/cc/index.asp?f=registrazione.htm" name="Opensky Registration site">. You'll receive a confirming email with login
|
|
and password in few days.
|
|
<item>
|
|
After you have to go to <url url="https://sdr.eutelsat.net" name="https://sdr.eutelsat.net"> and enter login and password data to connect.
|
|
<item>
|
|
Set the proxy: ''proxy.eutelsat.net:8080''.
|
|
</enum>
|
|
</p><p>
|
|
It is strongly suggested to use downloader applications (see Appendix A
|
|
for more) to get performance better.
|
|
</p>
|
|
<p>
|
|
OpenSky is the latest satellite service and it offers 300 MB at month (for
|
|
free).
|
|
</p>
|
|
<p>
|
|
Configuration is pretty like EON service, you have to use 0.8.2 siemens
|
|
drivers you download from <url url="http://www.linuxtv.org/download/dvb" name="LinuxTV">, then you NEED to patch dvbd applications.
|
|
</p>
|
|
<p>
|
|
To apply the patch and to test OpenSky you can find useful infos at:
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
<url url="http://members.tripod.com/andrei_b/linux/dvbd/dvb-app-dvbd.htm" name="http://members.tripod.com/andrei_b/linux/dvbd/dvb-app-dvbd.htm">
|
|
<item>
|
|
<url url="http://pguiral.free.fr/DVBS/opensky.html" name="http://pguiral.free.fr/DVBS/opensky.html">.
|
|
</itemize>
|
|
</p><sect>
|
|
Configuration under Windows
|
|
<sect1>
|
|
EON
|
|
<p>
|
|
Hauppage WinTV has DVB-DATA application that allows to specify data-link
|
|
settings.
|
|
</p>
|
|
<sect1>
|
|
Netsystem
|
|
<p>
|
|
First you need to install VPN capabilities.
|
|
</p>
|
|
<p>
|
|
In addition you need to download Netsystem software (always foreground
|
|
spot banner) and launch it: after you should not be able to use Netsystem service:
|
|
you can download it from <url url="http://bertolinux2000.interfree.it/Netsystem/Netsystem.zip" name="here">
|
|
</p>
|
|
<sect1>
|
|
OpenSky
|
|
<p>
|
|
See Linux.
|
|
</p>
|
|
<sect>
|
|
Appendix A - Notes
|
|
<sect1>
|
|
Translation Dynamic IP -> MAC Address
|
|
<p>
|
|
The translation used by some ISPs to calculate MAC address (which need
|
|
to have your DVB card to receive their packets) is:
|
|
</p>
|
|
<p>
|
|
00 : 01 : IP[0] : IP[1] : IP[2] : IP[3]
|
|
</p>
|
|
<p>
|
|
where
|
|
</p>
|
|
<p>
|
|
IP[0].IP[1].IP[2].IP[3] is your
|
|
dynamic IP address.
|
|
</p>
|
|
<p>
|
|
This feature is used, for example, by EON.
|
|
</p>
|
|
<sect1>
|
|
TCP Window
|
|
<p>
|
|
Satellite connections are an interesting example of very high RTT (round
|
|
trip time, access time): another example is the Mars - Earth communication
|
|
or also the Moon - Earth one.
|
|
</p>
|
|
<p>
|
|
These connections have a very bad feature: very low interactively.
|
|
</p>
|
|
<p>
|
|
Typical network (or digital, generally) connections use the so called transmission
|
|
"window", which represents the data buffer can be sent before waiting for an
|
|
answer. In TCP/IP protocol stack this is the TCP Window.
|
|
</p>
|
|
<p>
|
|
<verb>
|
|
----------------------
|
|
| - - - - - - - > can continue |-|-|-|---->
|
|
| ----------------------
|
|
| Buffer sendable before confirm
|
|
|
|
|
| - - - - - - - <----------------------
|
|
Confirmation Answering
|
|
</verb>
|
|
</p><p>
|
|
Now, if our communication has an high access time and if we had a little
|
|
TCP Window we would lose very much time only waiting for the data confirmation
|
|
(ACK), so the real bandwidth would decrease (for example if you have a 16KB
|
|
TCP window, typical of Windows systems and a RTT of 400 ms, you cannot overcome
|
|
16KB/0.4 = 40 KB/s)
|
|
</p>
|
|
<p>
|
|
Solution is to use a very high TCP Window (such as 256 KB or some MB).
|
|
</p>
|
|
<p>
|
|
Unfortunately, under many systems, is not so simple to have a great TCP
|
|
Window, so, in latest years, it starts to appear new applications ("download
|
|
accelerators" described in next section) that split in many pieces a file and
|
|
download all them in the main time: this is just equivalent to download only
|
|
one file with a single piece size, avoiding the RTT problem.
|
|
</p>
|
|
<sect1>
|
|
Download accelerator
|
|
<p>
|
|
We report here some useful link to so called "download accelerator" which
|
|
is an application that does 2 things:
|
|
</p>
|
|
<p>
|
|
<enum>
|
|
<item>
|
|
resuming session management, it allows stopping downloading and restarting
|
|
later (this can be done thanks to "resuming feature" introduced in Http and Ftp
|
|
server, which allows you to specify at what byte number start to download).
|
|
<item>
|
|
splitting, divide the file in many pieces and let them start in a multithreaded
|
|
fashion.
|
|
</enum>
|
|
</p><p>
|
|
As we saw in the previous section, a download accelerator allows us to
|
|
increase satellite bandwidth.
|
|
</p>
|
|
<sect2>
|
|
Under Linux
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
<url url="http://aria.rednoah.com/" name="Aria">
|
|
</itemize>
|
|
</p><sect2>
|
|
Under Windows
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
<url url="http://www.amazesoft.com" name="FlashGet">
|
|
<item>
|
|
<url url="http://www.getright.com" name="GetRight">
|
|
<item>
|
|
<url url="http://www.metaproducts.com" name="Mass Downloader">
|
|
</itemize>
|
|
</p><sect>
|
|
Appendix B - Well Known Sat ISP setting value
|
|
<sect1>
|
|
EuropeOnLine
|
|
<p>
|
|
EON sends data from Astra satellite (19.2 SE).
|
|
</p>
|
|
<p>
|
|
MAC address is calculated from IP address (see Appendix A).
|
|
</p>
|
|
<p>
|
|
It uses "Proxy Authentication".
|
|
</p>
|
|
<p>
|
|
Follows the 4 transponder setting:
|
|
</p>
|
|
<sect2>
|
|
Transponder 113
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 12633.250 MHz,
|
|
<item>
|
|
SRate : 22 MS/s
|
|
<item>
|
|
Polarization: Horizontal
|
|
<item>
|
|
Unicast PID: 512 (decimal)
|
|
</itemize>
|
|
</p><sect2>
|
|
Transponder 114
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 12640 MHz,
|
|
<item>
|
|
SRate : 22 MS/s
|
|
<item>
|
|
Polarization: Vertical
|
|
<item>
|
|
Unicast PID: 512 (decimal)
|
|
</itemize>
|
|
</p><sect2>
|
|
Transponder 115
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 12662.750 MHz,
|
|
<item>
|
|
SRate : 22 MS/s
|
|
<item>
|
|
Polarization: Horizontal
|
|
<item>
|
|
Unicast PID: 512 (decimal)
|
|
</itemize>
|
|
</p><sect2>
|
|
Transponder 103
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 12461 MHz,
|
|
<item>
|
|
SRate : 27.5 MS/s
|
|
<item>
|
|
Polarization: Horizontal
|
|
<item>
|
|
Unicast PID: 512 (decimal)
|
|
</itemize>
|
|
</p><sect1>
|
|
Netsystem
|
|
<p>
|
|
Netsystem uses Astra satellite (19.2 SE) to send data .
|
|
</p>
|
|
<p>
|
|
MAC address used is your real MAC address DVB card.
|
|
</p>
|
|
<p>
|
|
It uses VPN connection.
|
|
</p>
|
|
<p>
|
|
Follows data setting:
|
|
</p>
|
|
<sect2>
|
|
Transponder 119
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 12721 MHz
|
|
<item>
|
|
SRate: 22MS/s
|
|
<item>
|
|
Polarization: Horizontal
|
|
<item>
|
|
Unicast PID: 451 (decimal)
|
|
</itemize>
|
|
</p><sect1>
|
|
Sat Node
|
|
<p>
|
|
Sat Node uses Astra satellite (19.2 SE).
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 12603.750 MHz
|
|
<item>
|
|
SRate: 22MS/s
|
|
<item>
|
|
Polarization: Horizontal
|
|
<item>
|
|
Unicast PID: 302
|
|
</itemize>
|
|
</p><sect1>
|
|
Open Sky
|
|
<p>
|
|
Open sky uses Eutelsat satellite (7 SE).
|
|
</p>
|
|
<p>
|
|
<itemize>
|
|
<item>
|
|
Frequency: 11262 MHz
|
|
<item>
|
|
SRate: 27.5MS/s
|
|
<item>
|
|
Polarization: Horizontal
|
|
<item>
|
|
Unicast PID: 3003
|
|
</itemize>
|
|
</p><sect>
|
|
Links
|
|
<sect1>
|
|
Open
|
|
<p>
|
|
<url url="http://www.linuxtv.org" name="http://www.linuxtv.org">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.fatamorgana.com/bertolinux" name="http://www.fatamorgana.com/bertolinux"> <url url="http://www.hack-it.net/How-To/Sat-HOWTO.html" name="http://www.hack-it.net/How-To/Sat-HOWTO.html">
|
|
</p>
|
|
<sect1>
|
|
Commercial
|
|
<p>
|
|
<url url="http://www.europeonline.net" name="EuropeOnLine - EON">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.netsystem.com" name="Netsystem">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.starspeeder.com" name="Starspeeder">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.satnode.com" name="Sat Node">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.eliosat.com" name="Eliosat">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.falconstream.com" name="Falcon Stream ">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.skydsl.com" name="SkyDSL">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.opensky.it" name="OpenSky">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.direcpc.com" name="DirecPC">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.xanticbroadband.com/" name="http://www.xanticbroadband.com/">
|
|
</p>
|
|
<p>
|
|
<url url="http://www.fatamorgana.com" name="http://www.fatamorgana.com">
|
|
</p>
|
|
|
|
|
|
</article>
|