Hi,
Thanks to all who have answered my query. I have gone thro' your replies
and have discovered few other settings that I have to change in order to
make our Satellite connection more faster/better. So, I have few other
questions and hope they too will be answered.
1. What is the largest possible MTU size on Linux?
2. Does Redhat 6.1 (2.2.12-20smb) support large enough socket buffers?
Where do I change this value and how to know the current socket buffer
size?
3. How do I increase send and receive socket buffer sizes?
Thanks for your time in reading.
Rgds,
SMalla
On Mon, 31 Jan 2000, Matti Aarnio wrote:
> On Mon, Jan 31, 2000 at 02:21:50PM +0545, S. Malla wrote:
> > Hi all,
> >
> > Our organization uses VSAT connectivity for Internet Access and we are
> > advised to increase window sizing on our Linux (RedHat 6.1) servers to get
> > better result. What is the maximum possible size of window and how can I
> > increase it? Thanks for your time.
>
> You increase it at the code by using:
> int var = 200000;
> setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &var)
> setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &var)
>
> HOWEVER that is only benchmarkish thing, which doesn't
> help unless you have only *one* connection going at the link,
> and not at all at the usual fully saturated VSAT link case.
>
> In theory the window size you want is:
> ROUND-TRIP-DELAY * BANDWIDTH
> e.g. 0.8s * 64kbps = 51200
>
> With that you can get full bandwidth to one TCP stream,
> but as soon as you have more of parallel streams, default
> window of 32000 is quite sufficient.
>
> This is even assuming that the source is able to send to you
> at that whopping 64kbps speed - very popular sites in the net
> are so saturated that they send some 8-16 kbps at most..
>
> There is cotcha at Linux SO_SNDBUF code, though. It includes
> also SKB overheads in the book-keeping, and that share depends
> on the MTU of the connection. Say 80 bytes per each IP packet
> carrying 1460 bytes of TCP data. (5.5% overhead)
>
> > Rgds,
> > SMalla
>
> /Matti Aarnio
>
-
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to [EMAIL PROTECTED]
