Mailing List Archive: Asymmetric speed w/ SSH Port Forwarding

Asymmetric speed w/ SSH Port Forwarding

Jul 7, 2021, 8:41 AM

Post #1 of 8 (740 views)

Hi,

I was trying to have a SSH tunnel with at least 150Mbps/s in both directions.

I have a laptop computer under Ubuntu 20.04.2 and a remote server also
under Ubuntu 20.04.2.

I measured the speed of my internet connection with Iperf3 and without
SSH Tunnel it is OK.
$> iperf3 -c <SERVER_IP> -p 7503
- 500 Mbits/sec laptop -> server
$> iperf3 -c <SERVER_IP> -p 7503 -R
- 927 Mbits/sec laptop <- server

Then I open a SSH Tunnel: laptop -> server
$> ssh -L 7503:127.0.0.1:7503 root@my_server

Doing the iperf3 test again
$> iperf3 -c 127.0.0.1 -p 7503
- 13.6 Mbits/sec
$> iperf3 -c 127.0.0.1 -p 7503 -R
- 672 Mbits/sec

And now the speed is terrible from my laptop to the server.

In the iperf console this looks like this
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
[ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
[ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
[ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
[ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
[ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes

During some seconds there is no Bitrate at all :(.

I understand that the SSH tunnel will add some overhead and I will
lose around 10/20% of Bandwidth but this looks like a huge drop.

Do you have any idea what can create this behavior?

Thanks for your help,
Clement
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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

littlefox at lf-net

Jul 7, 2021, 9:11 AM

Post #2 of 8 (740 views)

Permalink

Hi,

Just to be sure, you also checked your internet connection - at home or wherever you were at the time?

Best
Mara

Am 7. Juli 2021 17:41:17 MESZ schrieb "Clément Péron" <peron.clem@gmail.com>:
>Hi,
>
>I was trying to have a SSH tunnel with at least 150Mbps/s in both
>directions.
>
>I have a laptop computer under Ubuntu 20.04.2 and a remote server also
>under Ubuntu 20.04.2.
>
>I measured the speed of my internet connection with Iperf3 and without
>SSH Tunnel it is OK.
>$> iperf3 -c <SERVER_IP> -p 7503
>- 500 Mbits/sec laptop -> server
>$> iperf3 -c <SERVER_IP> -p 7503 -R
>- 927 Mbits/sec laptop <- server
>
>Then I open a SSH Tunnel: laptop -> server
>$> ssh -L 7503:127.0.0.1:7503 root@my_server
>
>Doing the iperf3 test again
>$> iperf3 -c 127.0.0.1 -p 7503
>- 13.6 Mbits/sec
>$> iperf3 -c 127.0.0.1 -p 7503 -R
>- 672 Mbits/sec
>
>And now the speed is terrible from my laptop to the server.
>
>In the iperf console this looks like this
>[ ID] Interval Transfer Bitrate Retr Cwnd
>[ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
>[ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
>[ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>[ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>[ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>[ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>[ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>[ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>[ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>[ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>
>During some seconds there is no Bitrate at all :(.
>
>I understand that the SSH tunnel will add some overhead and I will
>lose around 10/20% of Bandwidth but this looks like a huge drop.
>
>Do you have any idea what can create this behavior?
>
>Thanks for your help,
>Clement
>_______________________________________________
>openssh-unix-dev mailing list
>openssh-unix-dev@mindrot.org
>https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev

--
Diese Nachricht wurde von meinem Android-Gerät mit K-9 Mail gesendet.
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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

peron.clem at gmail

Jul 7, 2021, 9:33 AM

Post #3 of 8 (740 views)

Permalink

Hi Mara,

On Wed, 7 Jul 2021 at 18:12, Mara Sophie Grosch <littlefox@lf-net.org> wrote:
>
> Hi,
>
> Just to be sure, you also checked your internet connection - at home or wherever you were at the time?

Yes I did both iperf3 yesterday with and without the SSH Tunnel at the
same time.
I also did both tests today just before sending my first email.

Speedtest of my connection gives ~920Mbps DL and ~600Mbps UP.

I also did the same test from my laptop but using an Internet
connection from my phone 4G to be sure it was not coming from my ISP.
Without SSH Tunnel iperf3 speed is 43Mbits/s and 48 Mbits/s
With SSH Tunnel iperf3 speed is 10Mbits/s and 36 Mbits/s

Even over my phone the Iperf3 log is very strange in one way:
[ 5] 0.00-1.00 sec 15.0 MBytes 126 Mbits/sec 1 1.19 MBytes
[ 5] 1.00-2.00 sec 5.00 MBytes 41.9 Mbits/sec 0 1.19 MBytes
[ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
[ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
[ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 7.00-8.00 sec 1.25 MBytes 10.5 Mbits/sec 1 639 KBytes
[ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
[ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes

I also tried another remote server and it gave me the same result.
One way is OK, the other seems limited by something...

Regards,
Clement

>
> Best
> Mara
>
> Am 7. Juli 2021 17:41:17 MESZ schrieb "Clément Péron" <peron.clem@gmail.com>:
> >Hi,
> >
> >I was trying to have a SSH tunnel with at least 150Mbps/s in both
> >directions.
> >
> >I have a laptop computer under Ubuntu 20.04.2 and a remote server also
> >under Ubuntu 20.04.2.
> >
> >I measured the speed of my internet connection with Iperf3 and without
> >SSH Tunnel it is OK.
> >$> iperf3 -c <SERVER_IP> -p 7503
> >- 500 Mbits/sec laptop -> server
> >$> iperf3 -c <SERVER_IP> -p 7503 -R
> >- 927 Mbits/sec laptop <- server
> >
> >Then I open a SSH Tunnel: laptop -> server
> >$> ssh -L 7503:127.0.0.1:7503 root@my_server
> >
> >Doing the iperf3 test again
> >$> iperf3 -c 127.0.0.1 -p 7503
> >- 13.6 Mbits/sec
> >$> iperf3 -c 127.0.0.1 -p 7503 -R
> >- 672 Mbits/sec
> >
> >And now the speed is terrible from my laptop to the server.
> >
> >In the iperf console this looks like this
> >[ ID] Interval Transfer Bitrate Retr Cwnd
> >[ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
> >[ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
> >[ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >[ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >[ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >[ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >[ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >[ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >[ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >[ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >
> >During some seconds there is no Bitrate at all :(.
> >
> >I understand that the SSH tunnel will add some overhead and I will
> >lose around 10/20% of Bandwidth but this looks like a huge drop.
> >
> >Do you have any idea what can create this behavior?
> >
> >Thanks for your help,
> >Clement
> >_______________________________________________
> >openssh-unix-dev mailing list
> >openssh-unix-dev@mindrot.org
> >https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
>
> --
> Diese Nachricht wurde von meinem Android-Gerät mit K-9 Mail gesendet.
> _______________________________________________
> openssh-unix-dev mailing list
> openssh-unix-dev@mindrot.org
> https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
_______________________________________________
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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

ronf at timeheart

Jul 7, 2021, 9:38 AM

Post #4 of 8 (740 views)

Permalink

Make sure SSH compression is disabled - this can have a massive impact on speed when it is enabled. Even though compression reduces the amount of data you need to put on the wire, potentially increasing what will fit on the link, the CPU cost to do the compression generally makes it a bottleneck on faster links like this.

On Jul 7, 2021, at 9:33 AM, Clément Péron <peron.clem@gmail.com> wrote:
> On Wed, 7 Jul 2021 at 18:12, Mara Sophie Grosch <littlefox@lf-net.org> wrote:
>> Just to be sure, you also checked your internet connection - at home or wherever you were at the time?
>
> Yes I did both iperf3 yesterday with and without the SSH Tunnel at the
> same time.
> I also did both tests today just before sending my first email.
>
> Speedtest of my connection gives ~920Mbps DL and ~600Mbps UP.
>
> I also did the same test from my laptop but using an Internet
> connection from my phone 4G to be sure it was not coming from my ISP.
> Without SSH Tunnel iperf3 speed is 43Mbits/s and 48 Mbits/s
> With SSH Tunnel iperf3 speed is 10Mbits/s and 36 Mbits/s
>
> Even over my phone the Iperf3 log is very strange in one way:
> [ 5] 0.00-1.00 sec 15.0 MBytes 126 Mbits/sec 1 1.19 MBytes
> [ 5] 1.00-2.00 sec 5.00 MBytes 41.9 Mbits/sec 0 1.19 MBytes
> [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> [ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> [ 5] 7.00-8.00 sec 1.25 MBytes 10.5 Mbits/sec 1 639 KBytes
> [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>
> I also tried another remote server and it gave me the same result.
> One way is OK, the other seems limited by something...
>
> Regards,
> Clement
>
>>
>> Best
>> Mara
>>
>> Am 7. Juli 2021 17:41:17 MESZ schrieb "Clément Péron" <peron.clem@gmail.com>:
>>> Hi,
>>>
>>> I was trying to have a SSH tunnel with at least 150Mbps/s in both
>>> directions.
>>>
>>> I have a laptop computer under Ubuntu 20.04.2 and a remote server also
>>> under Ubuntu 20.04.2.
>>>
>>> I measured the speed of my internet connection with Iperf3 and without
>>> SSH Tunnel it is OK.
>>> $> iperf3 -c <SERVER_IP> -p 7503
>>> - 500 Mbits/sec laptop -> server
>>> $> iperf3 -c <SERVER_IP> -p 7503 -R
>>> - 927 Mbits/sec laptop <- server
>>>
>>> Then I open a SSH Tunnel: laptop -> server
>>> $> ssh -L 7503:127.0.0.1:7503 root@my_server
>>>
>>> Doing the iperf3 test again
>>> $> iperf3 -c 127.0.0.1 -p 7503
>>> - 13.6 Mbits/sec
>>> $> iperf3 -c 127.0.0.1 -p 7503 -R
>>> - 672 Mbits/sec
>>>
>>> And now the speed is terrible from my laptop to the server.
>>>
>>> In the iperf console this looks like this
>>> [ ID] Interval Transfer Bitrate Retr Cwnd
>>> [ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
>>> [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
>>> [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>>> [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>>> [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>>> [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>>> [ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>>> [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>>> [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
>>> [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
>>>
>>> During some seconds there is no Bitrate at all :(.
>>>
>>> I understand that the SSH tunnel will add some overhead and I will
>>> lose around 10/20% of Bandwidth but this looks like a huge drop.
>>>
>>> Do you have any idea what can create this behavior?
>>>
>>> Thanks for your help,
>>> Clement

--
Ron Frederick
ronf@timeheart.net

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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

peron.clem at gmail

Jul 7, 2021, 9:58 AM

Post #5 of 8 (740 views)

Permalink

Hi Ron

On Wed, 7 Jul 2021 at 18:38, Ron Frederick <ronf@timeheart.net> wrote:
>
> Make sure SSH compression is disabled - this can have a massive impact on speed when it is enabled. Even though compression reduces the amount of data you need to put on the wire, potentially increasing what will fit on the link, the CPU cost to do the compression generally makes it a bottleneck on faster links like this.

Added '-v' to my SSH port forwarding cmd:

debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC:
<implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC:
<implicit> compression: none

I did a capture with wireshark and I saw lots of [TCP Dup ACK] when
the iperf3 was showing 0.00bits/sec.

Regards,
Clement

>
> On Jul 7, 2021, at 9:33 AM, Clément Péron <peron.clem@gmail.com> wrote:
> > On Wed, 7 Jul 2021 at 18:12, Mara Sophie Grosch <littlefox@lf-net.org> wrote:
> >> Just to be sure, you also checked your internet connection - at home or wherever you were at the time?
> >
> > Yes I did both iperf3 yesterday with and without the SSH Tunnel at the
> > same time.
> > I also did both tests today just before sending my first email.
> >
> > Speedtest of my connection gives ~920Mbps DL and ~600Mbps UP.
> >
> > I also did the same test from my laptop but using an Internet
> > connection from my phone 4G to be sure it was not coming from my ISP.
> > Without SSH Tunnel iperf3 speed is 43Mbits/s and 48 Mbits/s
> > With SSH Tunnel iperf3 speed is 10Mbits/s and 36 Mbits/s
> >
> > Even over my phone the Iperf3 log is very strange in one way:
> > [ 5] 0.00-1.00 sec 15.0 MBytes 126 Mbits/sec 1 1.19 MBytes
> > [ 5] 1.00-2.00 sec 5.00 MBytes 41.9 Mbits/sec 0 1.19 MBytes
> > [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > [ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > [ 5] 7.00-8.00 sec 1.25 MBytes 10.5 Mbits/sec 1 639 KBytes
> > [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >
> > I also tried another remote server and it gave me the same result.
> > One way is OK, the other seems limited by something...
> >
> > Regards,
> > Clement
> >
> >>
> >> Best
> >> Mara
> >>
> >> Am 7. Juli 2021 17:41:17 MESZ schrieb "Clément Péron" <peron.clem@gmail.com>:
> >>> Hi,
> >>>
> >>> I was trying to have a SSH tunnel with at least 150Mbps/s in both
> >>> directions.
> >>>
> >>> I have a laptop computer under Ubuntu 20.04.2 and a remote server also
> >>> under Ubuntu 20.04.2.
> >>>
> >>> I measured the speed of my internet connection with Iperf3 and without
> >>> SSH Tunnel it is OK.
> >>> $> iperf3 -c <SERVER_IP> -p 7503
> >>> - 500 Mbits/sec laptop -> server
> >>> $> iperf3 -c <SERVER_IP> -p 7503 -R
> >>> - 927 Mbits/sec laptop <- server
> >>>
> >>> Then I open a SSH Tunnel: laptop -> server
> >>> $> ssh -L 7503:127.0.0.1:7503 root@my_server
> >>>
> >>> Doing the iperf3 test again
> >>> $> iperf3 -c 127.0.0.1 -p 7503
> >>> - 13.6 Mbits/sec
> >>> $> iperf3 -c 127.0.0.1 -p 7503 -R
> >>> - 672 Mbits/sec
> >>>
> >>> And now the speed is terrible from my laptop to the server.
> >>>
> >>> In the iperf console this looks like this
> >>> [ ID] Interval Transfer Bitrate Retr Cwnd
> >>> [ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
> >>> [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
> >>> [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >>> [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >>> [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >>> [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >>> [ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >>> [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >>> [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> >>> [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> >>>
> >>> During some seconds there is no Bitrate at all :(.
> >>>
> >>> I understand that the SSH tunnel will add some overhead and I will
> >>> lose around 10/20% of Bandwidth but this looks like a huge drop.
> >>>
> >>> Do you have any idea what can create this behavior?
> >>>
> >>> Thanks for your help,
> >>> Clement
>
> --
> Ron Frederick
> ronf@timeheart.net
>
>
>
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openssh-unix-dev mailing list
openssh-unix-dev@mindrot.org
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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

peron.clem at gmail

Jul 8, 2021, 2:35 AM

Post #6 of 8 (740 views)

Permalink

Hi,

On Wed, 7 Jul 2021 at 18:58, Clément Péron <peron.clem@gmail.com> wrote:
>
> Hi Ron
>
> On Wed, 7 Jul 2021 at 18:38, Ron Frederick <ronf@timeheart.net> wrote:
> >
> > Make sure SSH compression is disabled - this can have a massive impact on speed when it is enabled. Even though compression reduces the amount of data you need to put on the wire, potentially increasing what will fit on the link, the CPU cost to do the compression generally makes it a bottleneck on faster links like this.
>
> Added '-v' to my SSH port forwarding cmd:
>
> debug1: kex: algorithm: curve25519-sha256
> debug1: kex: host key algorithm: ecdsa-sha2-nistp256
> debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC:
> <implicit> compression: none
> debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC:
> <implicit> compression: none
>
> I did a capture with wireshark and I saw lots of [TCP Dup ACK] when
> the iperf3 was showing 0.00bits/sec.
>
> Regards,
> Clement
>
> >
> > On Jul 7, 2021, at 9:33 AM, Clément Péron <peron.clem@gmail.com> wrote:
> > > On Wed, 7 Jul 2021 at 18:12, Mara Sophie Grosch <littlefox@lf-net.org> wrote:
> > >> Just to be sure, you also checked your internet connection - at home or wherever you were at the time?
> > >
> > > Yes I did both iperf3 yesterday with and without the SSH Tunnel at the
> > > same time.
> > > I also did both tests today just before sending my first email.
> > >
> > > Speedtest of my connection gives ~920Mbps DL and ~600Mbps UP.
> > >
> > > I also did the same test from my laptop but using an Internet
> > > connection from my phone 4G to be sure it was not coming from my ISP.
> > > Without SSH Tunnel iperf3 speed is 43Mbits/s and 48 Mbits/s
> > > With SSH Tunnel iperf3 speed is 10Mbits/s and 36 Mbits/s

I redid the test at home with a different ISP Provider and I don't
have the issue anymore.

The Fiber at my office and the 4G operator were the same brand so
maybe it was using the same backhaul and they may have a "filter" in
their infrastructure.

Regards,
Clement

> > >
> > > Even over my phone the Iperf3 log is very strange in one way:
> > > [ 5] 0.00-1.00 sec 15.0 MBytes 126 Mbits/sec 1 1.19 MBytes
> > > [ 5] 1.00-2.00 sec 5.00 MBytes 41.9 Mbits/sec 0 1.19 MBytes
> > > [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > [ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > [ 5] 7.00-8.00 sec 1.25 MBytes 10.5 Mbits/sec 1 639 KBytes
> > > [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > >
> > > I also tried another remote server and it gave me the same result.
> > > One way is OK, the other seems limited by something...
> > >
> > > Regards,
> > > Clement
> > >
> > >>
> > >> Best
> > >> Mara
> > >>
> > >> Am 7. Juli 2021 17:41:17 MESZ schrieb "Clément Péron" <peron.clem@gmail.com>:
> > >>> Hi,
> > >>>
> > >>> I was trying to have a SSH tunnel with at least 150Mbps/s in both
> > >>> directions.
> > >>>
> > >>> I have a laptop computer under Ubuntu 20.04.2 and a remote server also
> > >>> under Ubuntu 20.04.2.
> > >>>
> > >>> I measured the speed of my internet connection with Iperf3 and without
> > >>> SSH Tunnel it is OK.
> > >>> $> iperf3 -c <SERVER_IP> -p 7503
> > >>> - 500 Mbits/sec laptop -> server
> > >>> $> iperf3 -c <SERVER_IP> -p 7503 -R
> > >>> - 927 Mbits/sec laptop <- server
> > >>>
> > >>> Then I open a SSH Tunnel: laptop -> server
> > >>> $> ssh -L 7503:127.0.0.1:7503 root@my_server
> > >>>
> > >>> Doing the iperf3 test again
> > >>> $> iperf3 -c 127.0.0.1 -p 7503
> > >>> - 13.6 Mbits/sec
> > >>> $> iperf3 -c 127.0.0.1 -p 7503 -R
> > >>> - 672 Mbits/sec
> > >>>
> > >>> And now the speed is terrible from my laptop to the server.
> > >>>
> > >>> In the iperf console this looks like this
> > >>> [ ID] Interval Transfer Bitrate Retr Cwnd
> > >>> [ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
> > >>> [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
> > >>> [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > >>> [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > >>> [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > >>> [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > >>> [ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > >>> [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > >>> [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > >>> [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > >>>
> > >>> During some seconds there is no Bitrate at all :(.
> > >>>
> > >>> I understand that the SSH tunnel will add some overhead and I will
> > >>> lose around 10/20% of Bandwidth but this looks like a huge drop.
> > >>>
> > >>> Do you have any idea what can create this behavior?
> > >>>
> > >>> Thanks for your help,
> > >>> Clement
> >
> > --
> > Ron Frederick
> > ronf@timeheart.net
> >
> >
> >
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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

peron.clem at gmail

Jul 8, 2021, 2:49 AM

Post #7 of 8 (740 views)

Permalink

Hi,

On Thu, 8 Jul 2021 at 11:35, Clément Péron <peron.clem@gmail.com> wrote:
>
> Hi,
>
> On Wed, 7 Jul 2021 at 18:58, Clément Péron <peron.clem@gmail.com> wrote:
> >
> > Hi Ron
> >
> > On Wed, 7 Jul 2021 at 18:38, Ron Frederick <ronf@timeheart.net> wrote:
> > >
> > > Make sure SSH compression is disabled - this can have a massive impact on speed when it is enabled. Even though compression reduces the amount of data you need to put on the wire, potentially increasing what will fit on the link, the CPU cost to do the compression generally makes it a bottleneck on faster links like this.
> >
> > Added '-v' to my SSH port forwarding cmd:
> >
> > debug1: kex: algorithm: curve25519-sha256
> > debug1: kex: host key algorithm: ecdsa-sha2-nistp256
> > debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC:
> > <implicit> compression: none
> > debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC:
> > <implicit> compression: none
> >
> > I did a capture with wireshark and I saw lots of [TCP Dup ACK] when
> > the iperf3 was showing 0.00bits/sec.
> >
> > Regards,
> > Clement
> >
> > >
> > > On Jul 7, 2021, at 9:33 AM, Clément Péron <peron.clem@gmail.com> wrote:
> > > > On Wed, 7 Jul 2021 at 18:12, Mara Sophie Grosch <littlefox@lf-net.org> wrote:
> > > >> Just to be sure, you also checked your internet connection - at home or wherever you were at the time?
> > > >
> > > > Yes I did both iperf3 yesterday with and without the SSH Tunnel at the
> > > > same time.
> > > > I also did both tests today just before sending my first email.
> > > >
> > > > Speedtest of my connection gives ~920Mbps DL and ~600Mbps UP.
> > > >
> > > > I also did the same test from my laptop but using an Internet
> > > > connection from my phone 4G to be sure it was not coming from my ISP.
> > > > Without SSH Tunnel iperf3 speed is 43Mbits/s and 48 Mbits/s
> > > > With SSH Tunnel iperf3 speed is 10Mbits/s and 36 Mbits/s
>
>
> I redid the test at home with a different ISP Provider and I don't
> have the issue anymore.
>
> The Fiber at my office and the 4G operator were the same brand so
> maybe it was using the same backhaul and they may have a "filter" in
> their infrastructure.

In case someone has the same issue
changing the QoS fixed my issue.

IPQoS 0x00 > /etc/ssh/ssh_config

Regards,
Clement

>
>
> Regards,
> Clement
>
>
> > > >
> > > > Even over my phone the Iperf3 log is very strange in one way:
> > > > [ 5] 0.00-1.00 sec 15.0 MBytes 126 Mbits/sec 1 1.19 MBytes
> > > > [ 5] 1.00-2.00 sec 5.00 MBytes 41.9 Mbits/sec 0 1.19 MBytes
> > > > [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > > [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > > [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > > [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > > [ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > > [ 5] 7.00-8.00 sec 1.25 MBytes 10.5 Mbits/sec 1 639 KBytes
> > > > [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > > [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > >
> > > > I also tried another remote server and it gave me the same result.
> > > > One way is OK, the other seems limited by something...
> > > >
> > > > Regards,
> > > > Clement
> > > >
> > > >>
> > > >> Best
> > > >> Mara
> > > >>
> > > >> Am 7. Juli 2021 17:41:17 MESZ schrieb "Clément Péron" <peron.clem@gmail.com>:
> > > >>> Hi,
> > > >>>
> > > >>> I was trying to have a SSH tunnel with at least 150Mbps/s in both
> > > >>> directions.
> > > >>>
> > > >>> I have a laptop computer under Ubuntu 20.04.2 and a remote server also
> > > >>> under Ubuntu 20.04.2.
> > > >>>
> > > >>> I measured the speed of my internet connection with Iperf3 and without
> > > >>> SSH Tunnel it is OK.
> > > >>> $> iperf3 -c <SERVER_IP> -p 7503
> > > >>> - 500 Mbits/sec laptop -> server
> > > >>> $> iperf3 -c <SERVER_IP> -p 7503 -R
> > > >>> - 927 Mbits/sec laptop <- server
> > > >>>
> > > >>> Then I open a SSH Tunnel: laptop -> server
> > > >>> $> ssh -L 7503:127.0.0.1:7503 root@my_server
> > > >>>
> > > >>> Doing the iperf3 test again
> > > >>> $> iperf3 -c 127.0.0.1 -p 7503
> > > >>> - 13.6 Mbits/sec
> > > >>> $> iperf3 -c 127.0.0.1 -p 7503 -R
> > > >>> - 672 Mbits/sec
> > > >>>
> > > >>> And now the speed is terrible from my laptop to the server.
> > > >>>
> > > >>> In the iperf console this looks like this
> > > >>> [ ID] Interval Transfer Bitrate Retr Cwnd
> > > >>> [ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes
> > > >>> [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes
> > > >>> [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > >>> [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > >>> [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > >>> [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > >>> [ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > >>> [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > >>> [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes
> > > >>> [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes
> > > >>>
> > > >>> During some seconds there is no Bitrate at all :(.
> > > >>>
> > > >>> I understand that the SSH tunnel will add some overhead and I will
> > > >>> lose around 10/20% of Bandwidth but this looks like a huge drop.
> > > >>>
> > > >>> Do you have any idea what can create this behavior?
> > > >>>
> > > >>> Thanks for your help,
> > > >>> Clement
> > >
> > > --
> > > Ron Frederick
> > > ronf@timeheart.net
> > >
> > >
> > >
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Re: Asymmetric speed w/ SSH Port Forwarding [ In reply to ]

t.glaser at tarent

Jul 8, 2021, 7:41 AM

Post #8 of 8 (740 views)

Permalink

On Thu, 8 Jul 2021, Clément Péron wrote:

> In case someone has the same issue
> changing the QoS fixed my issue.
>
> IPQoS 0x00 > /etc/ssh/ssh_config

Oooh. In that case, try without this change, but use the -T option
for ssh (rsync and other file transfer tools, for example, set this).

With -t, ssh will default to interactive/lowdelay QoS, with -T to bulk.

bye,
//mirabilos
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