Iridium trials

HaraldS

Well-Known Member
Joined
22 Nov 2001
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574
Location
on board or in Austria
www.taniwani.eu
Thought I'd share my Iridium testing results with you, even though they aren't all complete. Figured I can save you the bottle of Lagavulin that it cost me in air time.

In preparation for doing this at sea soon, I went and tried various ways of retrieving and e-mail with a 31k attachment. For me that is the dayly GRIB file for the weather rounting. I can probably knock that one down to 20k. It was in ZIP compressed form, so usually hard to compress more through Iridiums compression.

All tests were done on a laptop with W2000, but also loads of software installed that could potentially interfere.

First thing which is probably less relevant once on the boat, was that I found I need to reboot my computer if it has previously been connected on a private LAN, otherwise the the Apollo Driver (used for connecting to Iridium) would remain in state "dialing" indefinitely and the phone doesn't show any action.

Inversly, if the Apollo Driver is enabled, the Laptop crashes when trying to put it into standby mode.

One of the theoretically good ideas behind the Apollo software is, that it can disconnect if there is no traffic and then reconnect, when new need arises, pretending to the computer that it was connected all the time. This could save some air time, but could also help you avoid starting over with your transfers from the beginning, if the connection drops for some reason.

Certainly this works for a Web browser, but I have crashed Outlook showing an illegal address refernce and it sends Outlook Express back to the very begin, which is loading the inbox over again.

Clearly the best is to try to do it all during one connection as quick as you can.

I tried thre alternatives to retrive e-mail. (1) Through the Web browser, (2) IMAP using Outlook Express and (3) IMAP using Outlook.

I didn't bother trying MAPI (Microsoft) as this is already hopeless on the cell-phone.
I also didn't try POP3 since it doesn't allow selective mail retrival.

I tried it on two mail servers, fastmail, as was recommended on this forum and our private company mail server (Exchange) which needs to be accessed via VPN.

You may all not bother much about the later, but as a thumb rule, getting the VPN connected takes a bit over 2 minutes over Iridium and after being connected doing mail retrivals seems about 30% slower than straight to fastmail.fm

If your mail client is like mine, checking several mail accounts at various locations, it is time to turn the atomatic checking off for all but the one you want to go for via Iridium.

So the fastmail.fm results are:

(1) Web Browser access: The process of accessing the login page, logging in and displaying the inbox takes 2 minutes 40 seconds. Selecting the target message and loading the attachment of 31kb adds another 2:25, so I had a total connect time of 5:05.

(2) Outlook Express: I started OE in offline mode, went to display the fastmail inbox, selected an already loaded email, then connected via Iridium, and as soon as the connection was established, hit send/receive to refresh. To my surprise it started uploading all mails that were new since the last connection including attachments. Usually only POP has that problem, but I couldn't get around it in OE. There were about a 150kb to be loaded, so I stopped this test.

(3) Outlook: Same procedure as above. It is important to prepare everything, including openning the inbox on fastmail while offline and selecting an already read mail. (If nothing is selected and you connect and refresh, it will select and load the most recent mail, which may not be what you want.) This now worked approximately like I hoped: I connected Iridium, and as soon as this was ready, I hit send/receive. It took 38 seconds and the subject lines of the 5 yet unread emails showed up in the inbox. I quickly selected the one I wanted, opened it and asked to open the attachment. This added another 108 seconds until the file was open and I could disconnect the Iridium connection. Total duration 2:26.

So it seems that fastmail in connection with very careful and planned use of a mail client and IMAP is as good as it gets. Browser access is about twice as expensive.

Hope I could safe you some (air) time. I'll keep you posted if I learn more. In the summer I shall be able to add the experience of doing this via SSB and comapre that to Iridium.
 
Thanks for the information, it was very useful. I have no experience of IMAP, we will only be using the email for friends and family and maybe occasionally need to accept an attachment from son who is maintaining our accounts etc. IMAP seems very complicated to me but do you think it would be worth my while to learn how to use it. The guy from Marconi told me that it was very complicated and not to bother and just use POP. We wont have any other ISP other than the Iridium gateway and I really don't think that I will spend much time browsing. I have only five days left and then I lose my internet connection as we move on to the boat, so I'd need to practise soon. Any advice would be appreciated.
 
Norma
I am nowhere near as technically qualified as Haralds on this issue but I have just crewed on a 5 day passage from Maya Maya (Philippines) back to Hong Kong.
The skipper has a new Iridium 'phone and a Toshiba Lap Top.
Email worked perfectly including oone inbound with a large jpg attachment. Voice comms also fine. As a non techy..I was hugely impressed.
Cheers
Jonathan
 
Hi, I run a service which may be of some interest. It was specifically developed for Iridium systems, although it should be very good for all dialup users. We basically looked at what data gets transmitted in an email message and realised that you can get rid of between 1/2 and 9/10 of it. This obviously really speeds up your download times.

For iridium users it gets even better, we use SMS Text messages to your phone to alert you to new emails, and also send you the contents of your email to your phone. It is slightly inconvenient reading your email as a series of text messages, but it is free and "instant". It also means that you don't need to dialup just to see if you have new mail, and yet you can crack off a reply to an important message within minutes of receiving it.

The services offered at MailASail are growing fast and the latest features are a text based web-browser (which is REALLY fast), and a web-page that you can update just by sending emails to yourself (saves needing to learn HTML and fiddling with uploading stuff, etc)

Please take a look at http://www.mailasail.com for more info

You can IMAP, or POP (or webmail) to access your email, but I would recommend using POP over Iridium. IMAP has some theoretical advantages, including being able to download just part of an email, but in practice unless you have a specific need, the satellite delay time really kills the IMAP protocol and POP is likely to be faster (and easier)

(Anyone else please feel free to mail me offline if you would like to see timings or a longer discussion!)

http://www.mailasail.com
 
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