On Sun, Jun 08, 2003 at 02:42:57PM +1000, Robert Tillsley <[EMAIL PROTECTED]> wrote: > > > I am thinking of mounting a secondary switch(s) in the new building, > > with an uplink to the existing network, however, what sort of uplink > > should it be: > > > > 1. Is it worth putting fibre in? > > Putting Fibre between separate buildings is something that I think is a must. > As I understand it, it provides some electrical separation between computers > in different buildings which can be pretty important in cases of lightening > strikes etc.
This is correct, fibre runs between buildings prevent fault currents from faulty equipment, and induced or direct lightning strike transmission between buildings. > > Bare in mind the cost of any trenching required, and how hard the buildings > are to work in. (this covers any type of cable of course). Modern buildings > can be easier to work with. > If you are paying someone else to lay the cables (most likely in this situation) make sure they are data cablers who know what they are doing. I've seen quite a few shonky jobs out there when an electrician thought doing network cabling without any form of training or practice would be a good idea (think cables terminated into Krone punch downs in any old order, matching pins at each side, but not following colour codes printed on the little labels, causing failure due to the twisted pairs being incorrectly used. > I also think its worth paying close attention to detail such as finishing, > making sure that in wall cavities that the cable isn't stressed and if its > layed across any ceiling expanse that its suspended on wire. And > cosmetically, consider how the cable is going to enter the building, the > amount of hideous looking jobs that for an extra hour of time could have > looked so much nicer. > > > 2. What does it take to make a gigabit network instead of 100Mbit? > > Depending on what switches you use, you may either need new switches or if you > have modular switches you'll need gigabit adapters. You'll need the fibre > layed (usually the more cores you can afford the better. It provides you with > redundancy and room for future expansion). Modern switches and patches us SC > (2x rectangular ends) as apposed to ST (2x a bit like old coax). > > 1GB cards are usually quite a bit more expensive and often have less ports > than 100mb cards. > Don't forget that 1Gb copper is also available, which is quite economical for things like servers, as the NICs for it are now under $100 for some brands. Gigabit copper requires that the cables be either good Cat 5 or Cat 5e and up, but this shouldn't be a problem, as all reputable cablers lay a minimum of Cat 5e for networks these days. Another thing to keep in mind is that Gigabit copper uses all 4 pairs of the cable. > There are also different types of cable for different distances. For the life > of me, I can't remember their names right now (sick on a long weekend, > bugger!) Multi-mode is one. > In terms of basic major fibre categories, the scale of most to least attenuation and dispersion, it goes something like this: * Multimode Step Index (SI) - Cheap, widely used in LANs. * Multimode Graded Index (GI) * Single Mode (SM) - Good, widely used in telecommunications. Note there are quite a few other variants of fibre out there, but they are not relevant to basic LANs, and would be more a concern on DWDM systems. -- jon Teh -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
