ssh: Adjust window size to match OpenSSH

[calmh]

Currently, the ssh packages uses a 16 KB window size for all channels. Given the
windowing mechanism, this pretty much limits transfer rates to 16 KB * RTT which can be
very little indeed for high latency connections.

OpenSSH uses a max packet size if 32 KB (as does go.crypto/ssh) and a window size of 64
* packet size (i.e. 2 MB) for session and tcpip channels. (See CHAN_SES_WINDOW_DEFAULT
and friends in channels.h in the OpenSSH code).

This patch updates go.crypto/ssh to do the same. For my use cases it bumps transfer
rates for high latency connections from unusable to comfortable.

Attachments:

1. window-size.diff (2097 bytes)

[davecheney]

Comment 1:

This sounds like a reasonable change, I think I initially picked those values without
serious consideration.
I have not reviewed your patch. Please follow the contribution guidelines outlined here,
http://golang.org/doc/contribute.html.

Status changed to HelpWanted.

[calmh]

Comment 2:

CL created: https://golang.org/cl/18120043

[davecheney]

Comment 3:

This issue was closed by revision golang/crypto@4758fe8.

Status changed to Fixed.