Isn't the issue of the maximum number of cascaded switches mostly a questions of how long it would take to reconfigure the spanning tree when problems occur? A max of 7 is recommended based on the timing of Configuration BPDUs, etc.
I don't think it's really an issue of how much latency is involved in forwarding frames. The delay can be as small as 10 microseconds for 64-byte Ethernet frames crossing high-end switches. In this particular design, reconvergence of the spanning tree isn't really an issue. His network is just one linear branch of a tree no matter how you look at it! ;-) Of course, he could fix that........ Priscilla At 11:51 AM 3/29/02, Hartnell, George wrote: >In a 10Mb environ, what the heck! I would speculate that double-up won't >make an ROI out of consolidation. > >However, this brings up a nasty little problem I'm looking at, and I might >phrase this another way. "How many cascaded switching devices can exist in a >broadcast domain without creating unacceptable latency in the network?" > >I see some scary practices with repeated arrays of inexpensive switches, >"RAIS", if you will. Each time a new workstation room is set up, the answer >is to cascade more and more unmanaged hub/switches (sorry Cisco, it's a >money thing) on the rack or down the copper to the room, or both. While the >sweetness of low cost is succulent, surely there is a theoretical limit of >how many members of a "RAIS array" one can cram into a building. > >So, boy and girl wonders, I've heard the magic number of "7". Anyone want >to "do the math"? > >Very best and happy Friday, G. >VP OGC > > > > > Subject: Switch Design Question [7:39888] > > I am looking at this configuration: > > > > [PC]---[Switch1]---Fiber---[Switch2]---[Switch3]---[WirelessBr > > idge]---distance2miles---[WirelessBridge]---[4Switch10Mb]---[R > > outer]---[ISPInternet] > > > > The switches are all consist of 10Mb ports. The question. > > Whould it not be > > a better design to take out switch2 and switch3 and replace > > it with one > > switch with more ports. This would elimate one switch to > > traverse when the > > clients are accessing the Internet. ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39904&t=39888 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
