file transfer, ftp, tftp, bftp, uucp, nfs

[R. Kannan]

We need a file transfer library, which can handle a call like this:

	transfer_file(the_file,to_machine,with_name, in_the_directory)

This implies that the process calling this function has read permission at the
sending end and write permission at the receiving end.

We have done a preliminary study of the tools that exist:

	ftp: is interactive, needs password.
		Thus provides no security for non-interactive, sheel driven
		need. Password has to be present in shell script.

	bftp:
		Allows for background ftp. But still needs password 
	information.

	tftp: Does not need password, but offers no security at all. Also
	it may be very ineffcient, in the sense that the blocks of the
	files are sent as datagrams as opposed to ftp which uses ftp
	and the transfer is done in one connection.

	uucp: Only in UNIX domain.

	rcp: very slow uses rsh. Also needs .rhosts to be set up. When
	the users and processes that have to transfer file is inderterminate
	and vary dynamically, this is not a big help.

	nfs:  nfs has been designed and used for local area
	networks. Our file transfer domain may or may not be within the local
	network. It can be linked by internet ....
	Also sender must export and the receiver should mount the file
	system. Can a file be mounted (other than a creating  a
	dirctory and moving the file into that dir. and then
	exporting/mounting the directory) .

	What is the performance characteristics of nfs in a non-LAN.
	Has there been any study in this area.

We invite comments and suggestions on this topic. Expereinces etc...

DISCUSSION II: 

	Given that the destination and the source nodes are both in a 
LAN, how can we make sure that 
	1. both are nfs client 

	2. Both have the same nfs server

	3. If different servers, do they have the same file system,
	can they mount the file system in question, and what if a file system
	with indentical id is already present but different file content.

Are there ways one can detect these, so that our design can switch
between nfs and some other system we will implement for non-nfs
system.

Thank you very much in advance.


--kannan