If you really read somewhere that a bridge is a multi-port repeater, trash that reference. ;-) Bridges (switches) solve different problems than repeaters (hubs).
The original repeaters had just two ports (in and out). These repeaters were implemented to allow one to get around the limitation that a single coaxial-based Ethernet segment could be only 500 meters (10Base5 or Thick Ethernet) or 185 meters (10Base2 or Thin Ethernet). With a repeater you could connect a 500 meter segment to another 500 meter segment and not have a problem. The repeater amplified the signal so that the signal on one side propagated to the other side. The repeater repeated all bits. It didn't understand frames and worked with signals and bits. Then the engineers figured out that these repeaters could connect more than just two segments, and along came the multiport repeater. The multiport repeater evolved into a HUB. A bridge works at the next layer up. A bridge divides up collision domains and solves the over-utilization problem. Although it also solves distance restrictions, that's not its main intent. A bridge understands frames and hence can offer many features. The bridge evolved into a SWITCH. Priscilla At 05:34 AM 2/25/02, Kevin Cullimore wrote: >The classical repeater as described in the first couple of chapters of >nearly every networking/internetworking technologies survey is a little >before my time, but here are some thoughts: > >-bridges are often described as multi-port repeaters, leaving the impression >that mere repeaters have but a single port (please note, that the coinage >described might involve distinguishing ingress from egress ports, but that's >hardly clear to the uninitiated). I suppose that an argument might be made >to lend legitimacy to the practice of contrasting the prefix multi with >something other than a term specifically denoting "one" or "single", but I'm >not sure how relevant that will turn out to be as time erodes those cases >without corroborating evidence. > >-to the extent that the purpose of the repeater is to extend a LAN, one >might picture a device with two cables (or other data-traversing-friendly >media) attached: one connected to the original network, one connected to the >extension. I'm honestly not sure how else it would function. > >-to the extent that the characterization i've provided is accurate, it might >be useful to apply bridging concepts in order to discern the functionality >of the repeater. A bridge accepts packets on a given port and, by charter, >does NOT transmit replicas of those packets on the same (ingress) port. I >therefore picture a repeater as a device that has 2 connections: one to the >original network, one to the LAN extension. If this is the case, I would >presume that the relevant functionality is to perpetuate packets received on >one port to the other. If that is the case, the repeater cannot be said to >create a loop. Note: if a loop already exists, the repeater would perpetuate >that condition, by design. > >All: as I mentioned, repeaters ceased to be relevant before my time. If >anyone knows differently about the topics I've alluded to, please post your >dissenting statement. > >Thanks, > > >----- Original Message ----- >From: "mlh" >To: >Sent: Saturday, February 23, 2002 3:18 PM >Subject: How does repeater work? [7:36323] > > > > Could anybody tell me how repeaters work ? I don't understand how repeater > > can regenerate > > the two-way signals from both segment connected to the repeater. Isn't it > > forming a loop? > > Pls forgive me asking the stupid question. > > > > Thanks in advance. > > > > mlh ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=36420&t=36323 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
