Bruce, > Ron, I don't pretend to be expert in channel protocols, but from what I > read the FICON protocols are quite different from ESCON. I've read that > ESCON does a channel-CU conversation for each CCW in a chain, with data > blocks in between, but FICON batches up CCWs and usually sends an entire > CCW chain in one block. > > Did I dream this, or would be more accurate to say that FICON is zArch > channel programming encapsulated in FCP? I also believed that the > FICON extensions to FCP were to accomplish this, not for security >
There are probably a dozen ways to say it simply, but simple must ignore the nuances. FCP is a transport protocol that we can stuff things inside of. We could say that FICON is CKD over FCP, ESCON over FCP or zArch channel programming encapsulated in FCP? There are changes that FCP allow to occur (as you described), and there are ESCON limitations that remained in FICON for quite some time (e.g. single hop ISL). Personally I feel that ESCON on FCP is a comparable generalisation to SCSI over FCP and IP over FCP. Ron ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
