Thank you very much Rob. The bits I understood are invaluable info. :) Any resource online more in layman's terms? Biti On Nov 18, 2005, at 7:45 AM, Rob VanHooren wrote: > Hello. > > Not to toot my own horn, but take it from someone "who does this sort > of thing for a living" /grin/ : > > To make a long story short... > > IEEE 802.3 (10Mbps ethernet) distance is not 100ft it is 100m. For > buffer, commonly 90m is used. > Standard for 802.3z gigabit, as well as 100Mbps ethernet distances > are the same for a copper twisted-pair medium. > > It is not a question of >100m performance will be less; at > 100m it > should not be expected to function at all! > > Collisions have no place (i.e. do not exist) in a full-duplex > (switched) environment -- the microsegmentation of a switch > alleviates the requirement for the collisioning in CDMA to do > rudimentary flow-control. > > (can you even buy hubs at retail anymore? you'd have to look pretty > hard to find one I think -- most Linksys, SMC, DLink, etc SOHO > electronics are switching chipsets rather than the simple electrical > regeneration of a hub) > > There are also rules for cascade of hubs and switches (e.g. 3rd cable > run must be > 15m to avoid nasty interference). > 'nother rule of thumb... if you need to cross AC lines (romex or what > have you) do so perpendicularly, and with parallel runs stay at least > 6ft away (esp. true when near fluorescent ballasts). > > The 10ms latency for an ACK as described is not really an element to > consider. There is jitter and a 9.6 microsecond interframe gap, > perhaps that was what prompted you to recall 10<something> as a risk > to traffic. > > Hopefully this clarifies a few earlier misconceptions. > > cheers, > > R. > > > > > On 16-Nov-05, at 4:18 AM, Garth Phillips wrote: > >> Everything is always a debate with you isn't it Eric? >> >> Wireless networks are secure reliable and it is quite >> rare to see a greenfield site starting with wired >> Ethernet. And the expense difference is not so great, >> according to CIO magazine article a few months ago, >> about 5% more until you need to make changes to the >> infrastructure in which case wireless can be up to 20% >> cheaper. >> >> As for security, both Canada's CSIS and Homeland >> Security use wireless as part of their networks. >> >> On the limit thing, yes there is an ultimate distance >> for Ethernet cabling but it is far beyond 100Ft and >> VERY unlikely that in a home, even a palatial >> 10,000FT-2 one, you'd run up against it. Again the >> 100FT run limit is based on a calculation of how much >> traffic there is, how many devices and being able to >> detect collisions within a specific time limit. this >> is why it's called Collision Domain Architecture and >> not Limited Distance. While I've long forgotten the >> hard formula, I seem to recall that it can not take >> more then 10mS for traffic to travel to it's >> destination and back to the sending device for >> confirmation of a "good send" or collisions are not >> seen. The more traffic, the more collisions which slow >> down the whole LAN, and the shorter the distances can >> be. >> >> Future proof? While I can't watch television >> transmissions over the Internet 'cause the bandwidth >> from Rogers Hi-speed isn't enough, I can watch is >> seemlessly over a new wireless phone which is far >> cheaper than GB ethernet. >> >> By the way Eric, don't forget that the standard for >> both 100MB and GB Ethernet only permit an equally >> fixed amount of bandwidth to each device. In 10/100, >> the limit is 10MB. I don't what the fixed amount is >> for GB. >> _________________________________________________ >> >> For information concerning the MUGLO List just click on >> >> http://muglo.on.ca/Pages/joinus.html >> >> Our Archives can be viewed at >> >> http://www.freelists.org/archives/muglo >> >> Don't forget to periodically check our web site at: >> >> http://muglo.on.ca/ > > _________________________________________________ > > For information concerning the MUGLO List just click on > > http://muglo.on.ca/Pages/joinus.html > > Our Archives can be viewed at > > http://www.freelists.org/archives/muglo > > Don't forget to periodically check our web site at: > > http://muglo.on.ca/ > _________________________________________________ For information concerning the MUGLO List just click on http://muglo.on.ca/Pages/joinus.html Our Archives can be viewed at http://www.freelists.org/archives/muglo Don't forget to periodically check our web site at: http://muglo.on.ca/