to ftp or to sftp
Ftp is seen as an old-time unsecure protocol. Many shops nowadays have switched or are switching to sftp. I will try to point out some differences :
Compatibility: none. the protocol is completly different. Multiple graphical clients however do support both mode. But the basic “ftp” client will not work with sftp.
Ascii mode: only in ftp. In sftp, it is always binary so there will be no conversion. Also no blocksize, recordlength or primary/secondary space for your OS/390 connections.
Interactive mode: similar. you enter your username and password, do cd, put and get. But to quit, by will not work in sftp 
Use quit or exit instead
Batch mode: different. Most probably you will end up setting a private/public key infrastructure for your ssh connection and use scp (secure copy). If you are using a ssh client like putty, it is possible to do something like pscp -l user -pw password server:file .
Security: sftp is secure, ftp is not.
Speed: ftp is fast, sftp is slow 
!
Oh NOOOOOOO!!!!! What’s the point is bringing something new if it is slower !!!
Ok, let’s try to download a 100m file:
$ time (echo "open dbsrv01
user oracle secret
bin
get 100m"|ftp -n )
real 0m24.673s
user 0m0.030s
sys 0m0.016s
$ time scp -q oracle@dbsrv01:100m .
real 1m46.978s
user 0m0.108s
sys 0m0.202sit is about 4x slower! Is there anything we could do about it?
Well, maybe :
$ time scp -q -o Compression=yes oracle@dbsrv01:100m .
real 0m18.634s
user 0m0.748s
sys 0m0.452sssh/scp/sftp have a compression mode. If you are transferring your large files across a slow network, this may be an interesting option to consider !
OpenSSH homepage : http://www.openssh.org
Tags: Ascii Mode, Batch Mode, Compatibility, Compression Mode, Conversion, File Security, Graphical Clients, Interactive Mode, Nbsp, Old Time, Oracle, ORACLE BLOGS, Os 390, Protocol, Public Key Infrastructure, Putty, Secure Copy, Secure Ftp, Ssh Client, Ssh Connection, Time Echo