is Bus Topology practical with CAT5?

Discussion in 'Networking & Security' started by O2Flow, Feb 7, 2006.

  1. O2Flow

    O2Flow Limp Gawd

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    Ok so I have been studying network designs and was wondering how Bus topology could be practical with CAT5? wouldn't you have to run x times as much cable for the amount of drops (from say a patch panel)?

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  2. jpmkm

    jpmkm That Ain't Mayo On My Lip...

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    It's possible to implement a bus with cat5 I suppose. Each node would have two jacks - one to go to the previous node and one to the next node. Or have a "tap", which would essentially be a splitter(or combiner, I suppose), that would tie three cables together - one for the previous node, one for the next node, and one for the node you are connecting to. Logically it's really no different than using coax; it's just a different method of tapping the cable. Each node would see all traffic and would be able to put data out on the bus. But, as you know, like all bus architectures, all the nodes on the bus share the bandwidth, and you will have the obvious contention issues.

    It's really not practical, and I know of no networking standard that uses cat5 in a physical bus topology(other than perhaps some rs422/rs485 setups or something of that nature).
     
  3. SCSI-Terminator

    SCSI-Terminator Gawd

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    It would not be practical.

    You could bus them data wize by using a bunch of hubs at the T intersections since a hub will repeat all data sent to it across all of its output ports, but given the cheapness and avalibility of switches... hubs are perty much obsolite. Using swiches as opposed to hubs would make the network look more like a line, with spurrs comming off for the PCs.

    Some people still do 10base2 or 10base5 with coax, which has a bus like topology. Only reason you would still do it now is that the max cable lengh is longer than 10/100/1000baseT that you use Cat5 for, and you are too cheap to use switches as repeaters, or go to fibre for the long runs.

    In general thou, busses in networking are bad, because everyone is on the same Collision Domain. You need routers and switches to break them up, so you don't forward the data (and waste bandwith) to someone who doesn't need it.
     
  4. DragonNOA1

    DragonNOA1 [H]ardness Supreme

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    Ethernet runs on a logical Bus. :confused: :confused:
     
  5. jpmkm

    jpmkm That Ain't Mayo On My Lip...

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    Ethernet can also run on a physical bus in addition to the more common(today) physical star. And switched ethernet is almost more of a logical star than a logical bus since it breaks down the collision domain. But I think the OP was asking about cat5 cable in general, not necessarily anything directly related to ethernet.
     
  6. Asgorath

    Asgorath [H]ard|Gawd

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    You could, but you don't want to. KISS principal. Keep the number of points of failure to a bare minimum.

    I remember thinnet Coax and what a pain it was. Always jiggling it to get it to work...piece of crap.
     
  7. YeOldeStonecat

    YeOldeStonecat [H]ardForum Junkie

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    Yup.....my first network job....I pretty much cut my teeth on Artisoft LANtastic networks. Intel Pro-10 network cards, and their clunky client netbios software. At the time, it was better than Microsofts at networking old DOS based applications though.

    But yeah..that old coax bus....on larger networks...ugh...one terminator, cap, or T-bar with some static in it...the whole network would go down.