SSH on high latency links. Re: [Patch] TCP MD5SIG for OpenSSH

[Thomas ☃ Habets]

Don't these extra roundtrips further increase the latency of ssh
connection setup (e.g. imagine a high-bandwidth&&high-latency satelite
link) ? ssh is already a *PAIN* in that area, killing it's usefullness
for applications like "Distributed make" because the time to setup the
connection can be much longer than the command executed on the remote
side.

They would, but only when this non-default option was enabled.

OK... are there any good ideas how to mitigate the latency effect ([1]) ?

You could try mosh (https://mosh.mit.edu/).

[Howard Chu]

Post by Thomas ☃ Habets

Don't these extra roundtrips further increase the latency of ssh
connection setup (e.g. imagine a high-bandwidth&&high-latency satelite
link) ? ssh is already a *PAIN* in that area, killing it's usefullness
for applications like "Distributed make" because the time to setup the
connection can be much longer than the command executed on the remote
side.

They would, but only when this non-default option was enabled.

OK... are there any good ideas how to mitigate the latency effect ([1]) ?

You could try mosh (https://mosh.mit.edu/).

LINEMODE works too. https://github.com/hyc/OpenSSH-LINEMODE

[Roland Mainz]

Post by Howard Chu

Post by Thomas ☃ Habets

Don't these extra roundtrips further increase the latency of ssh
connection setup (e.g. imagine a high-bandwidth&&high-latency satelite
link) ? ssh is already a *PAIN* in that area, killing it's usefullness
for applications like "Distributed make" because the time to setup the
connection can be much longer than the command executed on the remote
side.

They would, but only when this non-default option was enabled.

OK... are there any good ideas how to mitigate the latency effect ([1]) ?

You could try mosh (https://mosh.mit.edu/).

LINEMODE works too. https://github.com/hyc/OpenSSH-LINEMODE

Isn't that an improvement only for interactive mode ? My point was
that something like $ ssh "$***@desthost" '/bin/true' # is
horrible slow compared to (Kerberised) rsh, and gets even worse on
high-latency links (problem is that the large number of roundtrips by
the ssh protocol makes the whole thing latency-sensitive to a high
degree).

----

Bye,
Roland

[Stuart Henderson]

Post by Roland Mainz
Isn't that an improvement only for interactive mode ? My point was
horrible slow compared to (Kerberised) rsh, and gets even worse on
high-latency links (problem is that the large number of roundtrips by
the ssh protocol makes the whole thing latency-sensitive to a high
degree).

Do you already know about ControlMaster and related options? If they fit
your use case, they help a lot.