Digression. In my then neighborhood in London (UK), I was the only one who bought Betamax, the quality was so much better than VHS as Gil said (but I couldn't get too many movies!). It also had the advantage that my house was one of the few that was not broken into and have their VCR stolen!
Back on topic. SNA/SDLC - in my view, as robust as z/OS today in terms of security etc. As Jon said, TCP won, but did we get 'the best'? I doubt it. ALH -----Original Message----- From: Paul Gilmartin <[email protected]> To: IBM-MAIN <[email protected]> Sent: Sat, 9 Nov 2013 13:12 Subject: SNA vs TCP/IP (was: z/OS is antique ...) On Tue, 5 Nov 2013 11:49:40 -0800, Jon Perryman wrote: >... sad that he's bringing others to the dark side. > ... >* z/OS: SNA existed long before TCP/IP was available. SNA was a robust, reliable and secure communications methodology. Once TCP was became available, we had the same situation as Betamax versus VHS. TCP won. > There's always a reason. Rarely is it an analogue of Gresham's Law, to which one partisan attributed the triumph of UNIX over VMS ("Bad software drives out good!") Betamax succumbed to the greater capacity of VHS cartridges; a decisive advantage in the eyes of consumers at a tipping point in time despite the higher quality of Beta in professionals' view. For many years thereafter I saw Beta only in the kits of TV news reporters on location. I think VHS had caught up in quality and Beta in capacity, but both camps has too much capital investment to switch. So, why TCP/IP over SNA? o Price? o Openness of standards and implementations (price, again)? o Institutional bias against a perceived single-vendor solution (openness, again)? o Structured name space (thereby larger and more easily partitioned/distributed)? o DNS (name space, again)? Imagine an alterate universe without TCP/IP but an Internet very simlar to ours; Google; Facebook; Skype; iTunes; NetFlix; and all; all running (FSVO) smoothly on SNA. What modifications or extensions had to be made to SNA to accommodate this? -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
