Hi There,

I'm looking into sat broadband access for a colleague. Does anyone have
any experience of the performance of the 2 way systems. I'm interested
in the latency as this will be used for VPN access. What is the typical
ping time of somewhere like www.yahoo.com ?
Thanks all
Simon

Simon wrote:

Ping on satelite is awful. >1000ms is fairly normal I think, the data has
to travel huge distances which is why the latency is so high...

Simon <simon@not-here.com> wrote:
We have been using Aramiska for the last year or so. Their service has
gradually been getting better as they upgrade equipment. We typically
get 500 kbps streaming rate on the 1 Mbps service during working hours
(I do an automatic test transfer every hour), peaking at 800-900 kbps
outside working hours. Ping time:

$ ping www.yahoo.com
PING www.yahoo.akadns.net (216.109.125.74) from 192.168.0.246 : 56(84) bytes of data.
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=0 ttl=47 time=932.444 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=1 ttl=47 time=934.938 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=2 ttl=47 time=741.988 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=3 ttl=47 time=708.099 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=4 ttl=47 time=705.444 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=5 ttl=47 time=810.638 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=6 ttl=47 time=708.965 msec
64 bytes from w1.www.dcn.yahoo.com (216.109.125.74): icmp_seq=7 ttl=47 time=678.667 msec

We use VPN quite a bit - it's fine for email and intranet browsing, a
bit slow for telnet as you'd expect. Fiddling with MTU and window size
can improve streaming VPN performance. I think I can get about 110
kbps over my home NTL 150k cable connection via VPN to work. Aramiska
support port forwarding for both PPTP and IPSEC. They also support SMTP
port forwarding for outgoing mail to be redirected to your internal
server. They have HTTP cacheing both on the access box on the customer
site and elsewhere in their network.

If we could get cable or ADSL, I would almost certainly go for that
instead - based on monthly cost and responsiveness of web surfing - but
we don't currently have the option.

Andrew.

Simon wrote:


If its geostationary and two way, the total round trip time is 4 times
the orbit radius - about 24000 miles from memory?

Which is nigh on 100,000 miles in total - somewhat over 500ms. Add a bit
more in for queueing and latency, and your perceived response to
keypress is getting on for a second or so.

If you use a modem type backlink, its a bit better.

Its OK for web access and e-mail, but it's totally useless for

- terminal sessions (telnet)
- online games
- remote file transfer of a type where the packet sizes are small (spend
all yer time waiting for acks).

I would NOT use it in a VPN scenario where you are e.g. connecting to
LAN services that cannot cope with the latency. I suspect it will be an
expensive mistake

Chris wrote:

Thanks very much guys for the replies, much appreciated.

Simon

The Natural Philosopher <a@b.c> wrote:
Not useless, just slow.

Wouldn't know. ;-)

We haven't had any trouble with http or ftp streaming. The common
approach to mitigating the effect of long round trip times (which are
not necessarily limited to satellite connections) is to have a larger
window during which packets may be received without ACKs being sent. The
size of the packets then becomes of little significance as long as the
window is the right size.

We use it with VPN fine - email, web, ftp. Expensive, yes, but not a
mistake. ;-)

Andrew.

Andrew Haylett wrote:


I was thinking more of remotely mounting the office file systems. Not
sure how SMB copes with big delayes.

I agree FTP, http, e-mail will all be fine.

I disagree that TELNET is useable in any practical way if what you type
takes a second to appear.

The Natural Philosopher <a@b.c> wrote:

SMB isn't very good over remote slowish connections anyway. For
example, it starts squirrelling stuff over the net even if you just
click on (select, not open) a file in a folder. My solution is to
provide a comprehensive web-based interface to our workgroups intranet
to allow upload, download, auto-compression of entire directories, etc.
It has plenty of useful side-effects, including avoiding the problem
of (workgroup) browsing not working properly over remote connections
anyway.

One has to develop a certain technique (mental buffering?) and fairly
accurate typing, but I certainly find it useable if sub-optimal (even
with vi!). VPN over ISDN (our backup solution) is certainly much more
responsive...

Andrew.

"Simon" <simon@not-here.com> wrote in message
news:3F1283CF.62088A3@not-here.com...
Just thought I'd add:

Pinging yahoo.com [66.218.71.198] with 32 bytes of data:

Reply from 66.218.71.198: bytes=32 time=310ms TTL=235
Reply from 66.218.71.198: bytes=32 time=331ms TTL=235
Reply from 66.218.71.198: bytes=32 time=330ms TTL=235
Reply from 66.218.71.198: bytes=32 time=311ms TTL=235

Ping statistics for 66.218.71.198:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 310ms, Maximum = 331ms, Average = 320ms

And thats with a standard 56k dialup. Think I know which I'd prefer between
the two.
The lag on satellite is totally inadequate for anything BUT web and email,
making it pretty useless for myself ;p

Regards,
Ian

"Simon" <simon@not-here.com> wrote in message
news:3F1298C9.9EF19285@not-here.com...

Word of advice about Arimiska, don't believe what they claim..

My company needed a solution to get our webserver online, Arimiska were
suggested, and when we contacted them, they said it wouldn't have been a
problem, however, after the dish and router/firewall was installed, when we
tried to get the Domain resolved to the routers IP address, they turned
round
and said they don't do it, and left us up sh1t creek..

Needless to say the system was removed after a month as we had no use for
it.

Be careful...

Dave