[sclug] Distributed computing

[Tony Sumner]

On Sat, Jan 18, 2003 at 11:42:37AM +0000, Greg-e wrote:

> Doesn't the 1026 port refer to a port that is randomly assigned by the
> OS. 

You may be right. i just found a reference to the Assigned Numbers
Database (used to be RFC1700) that says that numbers above 1023 are
'user-registered numbers' and the 'the client always initiates the use
of a service by contacting the rendezvous port and indicating in its
first message which function is needed. The rendezvous service then
... starts a process to perform the function'. So I am wondering why
this is not happening. Trouble is I don't have the source of the
protein-folding program so I think I'll write one of my own to do what
that is doing, viz send a get status request and see what packets come
back and where they go. But what you say certainly indicates that the
answer to my question 'should the number be in /etc/services?' is no.

The packet addressed to port 1026 should indicate which function is
needed. Where do I find this in the packet? This is a typical one:

IN=eth0 OUT= MAC=00:40:f4:58:4a:50:00:05:9a:d6:b8:a8:08:00
SRC=206.248.62.8 DST=80.5.144.178 LEN=60 TOS=0x00 PREC=0x00 TTL=252
ID=20603 DF PROTO=TCP SPT=80 DPT=1026 WINDOW=34752 RES=0x00 ACK SYN
URGP=0

Tony Sumner