Hmmm....For the 7 hop from edge thing, I stand corrected. Now that you mention "radius vs. diameter", I see what you mean. My thinking was that the diameter was calculated with the root at the center (3 switches to either side for 7 switches total). The problem with that is that it doesn't necessarily have to be three per side, it could be 6 on one and none on the other :( Just poor analysis on my part.
As for the 5-4-3 rule, I am going to disagree on a few counts. Here's how I remember it (from an admittedly long time ago): First, the slot time (64 byte time) isn't much of an issue unless running at 100Mbps or faster, and isn't an issue at all running full duplex. As I remember it, the problem with the slot time is that at 100Mbps, the slot time drops to something like 5.12 ms, which necessarily reduces the repeated network's diameter, as if a packet collides after the slot time it becomes a late collision, and the original host may not properly detect the collision. I seem to remember that there always being a recommendation, however, not to repeat the packet more than 5 times due to S/N Ratio problems creeping in after amplification. As for the switch vs. hub thing, I seem to remember based on the S/N thing that anything that amplified the original signal caused this problem. I also remember the distinction that under normal circumstances, the switch does not modify the packet in any way (L3/4 switches and trunking excluded). However, thinking about it, based solely on the switching mode, it seems that all switches (and even a lot of hubs now) buffer the packet in RAM and then forward it, which means, as someone stated, that the packet is "rebuilt". So, I agree with most of what you have said after all, with the exception of the S/N ratio having nothing to do with it. I do remember reading that the S/N ratio degradation was an issue after many amplifications of the original signal. As for me drinking by the pool, no, I am out of town at present, and just rattled off the reply. As I hope I have shown, I did have reasons for what I said, just perhaps the weren't thought out well enough. Brian Hill CCNP, CCDP, MCSE 2000 (Charter Member),MCSE+I (NT4.0), MCSA (Charter Member), MCP+I, MCP(21), Inet+, Net+, A+ Lead Technology Architect, TechTrain Author: Cisco, The Complete Reference http://www.alfageek.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=44460&t=44408 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
