[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: HELP- very slow download speeds



On 06/05/2015 12:57 AM, Petter Adsen wrote:
On Thu, 04 Jun 2015 16:44:53 -0700
Gary Roach <garyroach@verizon.net> wrote:

On 06/03/2015 11:55 PM, Petter Adsen wrote:
Well, it's not shut down, as I just tried it and it works fine here.
Maybe it was down, though, and you should try again?

If it still doesn't work, then check your firewall. It shouldn't give
you any problems, as you are simply trying to establish a connection to
port 5201 on a remote machine, but check. Enable firewall logging, if
possible, and see if anything gets blocked. Verify that you can reach
the webserver running on the same host.

Also try with UDP ("-u -b 0").

Petter

Well all of a sudden iperf.scottlinux.com works The send and receive
with TCP packets is about the same. Below is a typical example:

root@xxxxxxxxxx# iperf3 -c iperf.scottlinux.com -R -V
<snip>
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  32.4 MBytes  27.2 Mbits/sec 0             sender
[  4]   0.00-10.00  sec  32.2 MBytes  27.0 Mbits/sec
receiver
CPU Utilization: local/receiver 3.8% (0.6%u/3.2%s), remote/sender 0.1%
(0.0%u/0.1%s)

iperf Done.

   As you can see, I'm getting about half of the 50Mbits/sec for which I
contracted. But this is way better than my actual speed. I ran the same
test with udp packets and got:
When I tested against the same host last night I got around 40Mbps (I
also have 50Mbps), but I'm in Norway, so that doesn't seem so bad. I
tried again right now, and got ~45Mbps.

What do you mean that this is way better than your actual speed? This
_is_ the measured speed to this host :) Do you normally get lower speed
to other hosts?

Your ISP probably doesn't guarantee that you actually get 50Mbps
unless you have a business line, but most likely says "speeds _up to_
50Mbps" or something similar. So that would be normal.

Also try a few online speed tests, like the one at speed.io, and see
what they tell you. Your ISP might also have one.

root@xxxxxxx# iperf3 -c iperf.scottlinux.com -R -u -V
<snip>
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bandwidth       Jitter Lost/Total
Datagrams
[  4]   0.00-10.00  sec  1.26 MBytes  1.06 Mbits/sec  0.660 ms 0/161 (0%)
[  4] Sent 161 datagrams
CPU Utilization: local/receiver 0.3% (0.0%u/0.3%s), remote/sender 0.1%
(0.0%u/0.1%s)

iperf Done.

Now I'm really confused. I thought UDP packets were going through at
full speed and TCP plackets were slow. This data says just the opposite.
Yeah, Reco just explained this to me in a different thread. For UDP you
need to specify the target bandwidth, the default is 1Mbps. Use "-b 0"
to set it to unlimited. For earlier versions it needs to be at the end
of the line, don't know about iperf3. See the man page for details.

Petter

Petter

Most of my large downloads are from ftp.us.debian.org. Before I go any further, I probably need to switch to a mirror site and see if the problem persists. I have been assuming that, since this is debian's main server, that I shouldn't have a server problem. Assumptions can really kill you. Thanks for info on iperf3's udp speed. running "iperf3 -c iperf.scottlinux.com -V -u -b 0" works fine. I'll keep you posted about changing to a debian mirror. There is one at the Univerisity of California Berleley that is just up the coast from us.

Thanks again
Gary R



Reply to: