NetBios over tcp/ip: Unable to copy large files over slow connection

  • Thread starter Thread starter SMN
  • Start date Start date
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SMN

I have my computer (Windows XP) connected to a Window 2000 Server over a VPN
tunnel. A SonicWall is placed at each end of the VPN tunnel. The two
SonicWalls are connected by a 256/256 KBit xDSL connection.

I have no troubles browsing the Windows 2000 Server from my Windows XP. I
can also copy small files but when I try to copy larger files (>100KByte)
the connection fails.

I can see with a tcp/ip protocol monitor that the Windows XP computer is
connected to the Windows 2000 server through a tcp/ip connection with local
port number 139. When I copy a large file this connection is using all
bandwidth. Suddenly the bandwidth drops to zero and a few seconds later the
copy operation fails and the tcp/ip connection is dropped and replaced by a
new one.

I have tried different VPN hardware and get the same problem, so I don't
think it is a VPN problem. Also all other simultanious connections through
the VPN tunnel isn't dropped when the copy operation fails.

Can anyone help me with what might solve this problem?

Thanks,
SMN
 
I have my computer (Windows XP) connected to a Window 2000 Server over a VPN
tunnel. A SonicWall is placed at each end of the VPN tunnel. The two
SonicWalls are connected by a 256/256 KBit xDSL connection.

I have no troubles browsing the Windows 2000 Server from my Windows XP. I
can also copy small files but when I try to copy larger files (>100KByte)
the connection fails.

I can see with a tcp/ip protocol monitor that the Windows XP computer is
connected to the Windows 2000 server through a tcp/ip connection with local
port number 139. When I copy a large file this connection is using all
bandwidth. Suddenly the bandwidth drops to zero and a few seconds later the
copy operation fails and the tcp/ip connection is dropped and replaced by a
new one.

I have tried different VPN hardware and get the same problem, so I don't
think it is a VPN problem. Also all other simultanious connections through
the VPN tunnel isn't dropped when the copy operation fails.

Can anyone help me with what might solve this problem?

Thanks,
SMN
Click to expand...

You really shouldn't try to copy large files over a thin connection. Setup a free ftp server on the windows 2000 server, the internal one or filezilla, then use a FTP application to upload the file across the VPN.

When you do a network copy of a VPN connection the source computer will push as much data each 'copy' that it can, it will basically try to push the file faster than the remote computer will receive it.

If you use a FTP server, the file transfer protocol will break the file up into parts that are sent and received, without overloading the internet connection.
 
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