[syslinux] Etherboot & pxelinux (was: thank you)

[H. Peter Anvin]

Josef Siemes wrote:

> 
> We made some measurements about different blksizes at different bandwidth, 
> and it turned out that you gain few with LAN lines, but the lower the bandwith the more you gain with higher blksize. So higher blksize is only needed if you have some WAN line with low bandwidth.
> 


I suspect you actually mean "high latency" rather than "low bandwidth" 
since the main benefit is to reduce ping-pong.  This actually begs the 
question if a pretransmit option (send a packet before it gets the 
preceeding ACK) on the server would improve performance -- it would help 
  latency somewhat, but may increase retransmits.

Over high-latency links TFTP basically blows.  I was thinking about 
doing a "TFTP tcp option" (basically, if the client knows how to open a 
TCP socket, it could request the tcp option and get back a port number 
instead of a full TFTP connection.)  However, it's unclear to me how 
well this would work with PXE -- it's clear that PXE doesn't contain a 
TCP stack; what isn't clear is if it is possible to use the IP layer in 
PXE without in effect reimplementing it; it doesn't have a direct API, 
but there are some hints that it might be accessible via the UNDI API...

*Sigh*

	-hpa