SMB directly hosted on TCP

Ville Herva vherva at
Mon Nov 13 20:21:12 GMT 2000

On Mon, Nov 13, 2000 at 02:04:01PM -0600, you [Gerald Carter] claimed:
> Ville Herva wrote:
> > 
> > Direct hosted "NetBIOS-less" SMB traffic uses port 445 
> > (TCP and UDP). In this situation, a four-byte header 
> > precedes the SMB traffic. The first byte of this header 
> > is always 0x00, and the next three bytes are the length 
> > of the remaining data. You can use the following steps 
> > to disable NetBIOS over TCP/IP, forcing all SMB traffic 
> > to be direct hosted. "
> > 
> > This actually sounds quite good. It could in fact 
> > reduce overhead and improve performance. What do you think?
> > 
> > Would it make sense/be feasible to support this on Samba?
> The code to do this has been written in development 
> branches for a while.  We will try to being it over 
> some time in the near future.  Most certainly this 
> will happen after we get 2.2.0 out the door.


Have you idea whether that really affects the performance? I've seen SMB
(NetBios on TCP) have problems on non-standard environments. For example,
when I run smb over ssh port forwarding, the perfomance drops to one
fourth of the bandwidth, while other protocols (ftp, http) have no
problem. Also SMB does not exactly seem to be the fastest protocol on
Earth on 100Mbit ethernet media either ... ;). 

Perhaps dropping the NetBios on TCP legacy could remedy some of this?

> loose the virtual server functionality in 
> Samba with netbios-less CIFS as there is no called name 
> in the TCP session request. :-(

Perhaps that's worth it if we get somewhat better performance and can
forget about all this wins/broadcast/nameresolution stuff.

-- v --

v at

More information about the samba mailing list