Re: Simluating a satellite connection using dummynet?
I've been reading up on it and best I can tell I'm looking at 1000ms round trips... at *best*. Most of what I do I can do on servers at home, but there will be the occasional ssh, etc. Supposedly, the round trip should be only 500 ms: the time for the signal to go from earth to the satellite and back to earth, then the same time for the reply packet to come back. On the machine directly connected to the satellite modem, a ping to the machine at the other end, directly connected to the satellite modem (so the 2 machine as close as possible to the satellite equipment) I get a ping round trip of 800 ms. That speed is pretty workable for ssh/telnet, even for a full screen editor. Olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Simluating a satellite connection using dummynet?
Dan Busarow wrote: On Apr 22, 2006, at 9:40 PM, Philip Hallstrom wrote: Hi all - Odd question for you. I have the opportunity to work from home, but it would require using a sat internet connection (no cable or dsl anywhere close). I've been reading up on it and best I can tell I'm looking at 1000ms round trips... at *best*. Most of what I do I can do on servers at home, but there will be the occasional ssh, etc. I recently setup ipfw/dummynet with a pipe and a 750ms delay both in and out and it wasn't as bad as I thought it would be -- at least for ssh/text. Reminds me of my days on a 9600 baud modem. heh. I'm curious though whether this is a realistic test. Thoughts? Any of you use satellite? How do you find it? I had StarBand for about two years. 1000ms RTT are the best you will see. pushing 2000ms is more like it. While it is possible to work via an SSH session it will try your patience. It is doable, and it allowed me to move out to the country, but that's about it. I now have a terrestrial radio link into the nearest town, 15 miles away, and it's beautiful. My wife's employer had a Hughes connection for something over a year. Generally speaking, they weren't impressed. Their operation is a small insurance office, and they needed quick https service to the home office in Iowa, for a web app that seems to take a pretty quick pipe to operate well. I never ran a sniffer, but it seemed as if their OS (Microsoft) had some trouble with this setup, particularly with https traffic. You'd wait a good long time (few seconds), then get a big burst of data ... if you weren't cluttering things up with retries. Since this HTTPS traffic was his business, he decided it was more important to keep his employees happy, so he later decided to devote a portion of his disposable income to a local outfit that provides a T1 instead. TCP/IP being as it is, it's likely that MSFT QoS was dropping the packet sizes to help deal with the congestion ;-), but I was never sure. I'd concur that 1000 ms was a pretty normal RTT for ICMP, and it could, and often did go higher, a la 2500+. Much like Dan, I use an 11Mbps LOS radio connection to the water tower about 4 miles away. Nice, except I really need to raise my receiver so I can maintain good QoS when the foilage gets going I think grog@ has satellite service in AUS. You might see if you can turn up anything on his site. Kevin Kinsey -- And do you think (fop that I am) that I could be the Scarlet Pumpernickel? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Simluating a satellite connection using dummynet?
From: Kevin Kinsey [EMAIL PROTECTED]
Dan Busarow wrote:
On Apr 22, 2006, at 9:40 PM, Philip Hallstrom wrote:
Hi all -
Odd question for you. I have the opportunity to work
from home, but it would require using a sat internet
connection (no cable or dsl anywhere close).
I've been reading up on it and best I can tell I'm looking
at 1000ms round trips... at *best*. Most of what I do
I can do on servers at home, but there will be the
occasional ssh, etc.
I recently setup ipfw/dummynet with a pipe and a 750ms
delay both in and out and it wasn't as bad as I thought
it would be -- at least for ssh/text. Reminds me of my
days on a 9600 baud modem. heh.
I'm curious though whether this is a realistic test.
Thoughts?
Any of you use satellite? How do you find it?
I had StarBand for about two years. 1000ms RTT are the
best you will see. pushing 2000ms is more like it.
While it is possible to work via an SSH session it will
try your patience.
It is doable, and it allowed me to move out to the
country, but that's about it. I now have a terrestrial
radio link into the nearest town, 15 miles away, and
it's beautiful.
My wife's employer had a Hughes connection for something
over a year. Generally speaking, they weren't impressed.
Their operation is a small insurance office, and they needed
quick https service to the home office in Iowa, for a web app
that seems to take a pretty quick pipe to operate well.
I never ran a sniffer, but it seemed as if their OS (Microsoft)
had some trouble with this setup, particularly with https
traffic. You'd wait a good long time (few seconds), then get a
big burst of data ... if you weren't cluttering things up with
retries. Since this HTTPS traffic was his business, he
decided it was more important to keep his employees
happy, so he later decided to devote a portion of his
disposable income to a local outfit that provides a
T1 instead. TCP/IP being as it is, it's likely that MSFT
QoS was dropping the packet sizes to help deal
with the congestion ;-), but I was never sure.
I'd concur that 1000 ms was a pretty normal RTT for
ICMP, and it could, and often did go higher, a la
2500+.
Much like Dan, I use an 11Mbps LOS radio connection
to the water tower about 4 miles away. Nice, except
I really need to raise my receiver so I can maintain
good QoS when the foilage gets going
I think grog@ has satellite service in AUS. You might
see if you can turn up anything on his site.
Kevin Kinsey
Four round trips of as much as 25,000 miles is a bit more than
half a second. The typically employed interleaving/deinterleaving
and error correction coding means you can easily add another half
a second to the path.
(Of course, for something like the data mode operation on Inmarsat-M,
which is 2400bps max, it was pretty bad. As part of testing the
implementation I ran an interesting test. Satellite from Torrance to
the Atlantic sat to Goonhilly England (the only ground station that
was useable for the testing) back to LAX by unknown path thence
tymnet to a service in Mass to connect to the Internet and then
connect back to itself via TCP/IP was a LONG SLOW interactive session.
Then I made a 1 megabyte file transfer. It worked. It was signed off.
And quite a few units presold with data mode option suddenly grew the
implementation, one of the first units to have it. Then I entered
burnout Anyway - by the time that was all connected turn around
varied from 2.5 to 5 seconds on typed characters.)
{o.o} Joanne
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Simluating a satellite connection using dummynet?
Hi all - Odd question for you. I have the opportunity to work from home, but it would require using a sat internet connection (no cable or dsl anywhere close). I've been reading up on it and best I can tell I'm looking at 1000ms round trips... at *best*. Most of what I do I can do on servers at home, but there will be the occasional ssh, etc. I recently setup ipfw/dummynet with a pipe and a 750ms delay both in and out and it wasn't as bad as I thought it would be -- at least for ssh/text. Reminds me of my days on a 9600 baud modem. heh. I'm curious though whether this is a realistic test. Thoughts? Any of you use satellite? How do you find it? Thanks! -philip ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Simluating a satellite connection using dummynet?
On Apr 22, 2006, at 9:40 PM, Philip Hallstrom wrote: Hi all - Odd question for you. I have the opportunity to work from home, but it would require using a sat internet connection (no cable or dsl anywhere close). I've been reading up on it and best I can tell I'm looking at 1000ms round trips... at *best*. Most of what I do I can do on servers at home, but there will be the occasional ssh, etc. I recently setup ipfw/dummynet with a pipe and a 750ms delay both in and out and it wasn't as bad as I thought it would be -- at least for ssh/text. Reminds me of my days on a 9600 baud modem. heh. I'm curious though whether this is a realistic test. Thoughts? Any of you use satellite? How do you find it? I had StarBand for about two years. 1000ms RTT are the best you will see. pushing 2000ms is more like it. While it is possible to work via an SSH session it will try your patience. It is doable, and it allowed me to move out to the country, but that's about it. I now have a terrestrial radio link into the nearest town, 15 miles away, and it's beautiful. Dan ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
