Transfer of larges files fails on forwarded ports

Roberto A. Foglietta roberto.foglietta at gmail.com
Tue Jan 11 18:14:06 WST 2011


2011/1/11 Michael Wiedmann <michael.wiedmann at aastra.com>:
> Given the following scenario (simplified, port no. examples only,
> omitted auth):
>
> User                                            embedded system
> port 5000     -L ...    port 50000    -R ...    port 80
> ssh client <----------> SSH Server <----------> ssh client
> (plink/Win)          (dropbear/cygwin)          (dbclient)
>
> Workflow is like:
>
> - ssh client on right side (embedded system) initiates ssh session to
>  dropbear ssh server requesting _remote_ port forwarding
> - ssh client on left side (PC) initiates ssh session to the same
>  dropbear ssh server requesting _local_ port forwarding
>
> - User on the left side can point his web browser to localhost:5000
>  and reaches via ssh tunnel and the forwarded ports the web server
>  on the embedded device (port 80)
>
> - this works so far for "simple" web pages:
>  User can browse configuration pages on the embedded device,
>  make changes, etc.
>
> BUT
>
> if we try to transfer a "large" file via HTTP upload over the
> tunnel/forwarded port
> the transfer fails at same point (around 500 kB, varying).
>

 Packet size could vary then overhead/data size too. Could it be 512Kb
(fixed size) included TCP/IP protocol overhead?

 Cheers,
-- 
Roberto A. Foglietta,


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