Ted, What sort of extension equipment are you talking about?
For ESCON, 9km is knee in the curve for "droop". I think the distance with MM was 2km, and SM was 20k. Combining MM and SM I think ESCD or XDF allowed was supported to 47km, and DWDM would run to 60km, and at that point you are down to about 4MB/sec data rate. The Fibre Channel protocol will support MM up to 500m and SM up to 10km, and most HBA and/or Device ports have enough buffer credits to handle about 6km at 1Gb. FCP ISL using DWDM can work pretty well up to 200km, but you have to have enough buffer credits to get the full data rate. For buffer credits, don't just use the typical rules of thumb that are out in the market place. They are based on 2112 byte frame size, but there is a lot of equipment using smaller frames, which increases the number of credits needed for the same distance. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of Ted MacNEIL > Sent: Sunday, 11 December 2005 2:09 PM > To: [email protected] > Subject: Channel Distances > > I was asked the maximum distance that an ESCON Channel > could span. > IIRC, it was 40km for CTC, 20km for tape, and 9km for DASD. > I was not believed. > > Does anybody know? > And, where would I look this up? > I haven't really cared since the early 1990's. > > Also, does anybody remember the distances for parallel > (1.1, 1.5, 3.0, & 4MB/s -- if I recall all the speeds)? > > Also, what about FICON (all flavours)? > > Again, does anybody know where I could look this up? > I have forgotten (getting old is not for sissies!). > -teD > Me? A skeptic? I trust you have proof! > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- 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
