Ned, Thanks for the pointers. The cost factor isn't in play here as when and if this gets accomplished the school may not go with a wiring company but rely on in house help to get it accomplished. I truly understand the cost factor. Most of the drops on this network are used for printing, Internet (Email, normal surfing hopefully job related), an application that uses ssh and Remote Desktop applications.
The reason for the look at rewiring is a recent outage on this LAN that got me involved. This LAN is the administrative LAN and not the educational side which seems to run okay (knock on simulated wood). The 100' seems to be the magic number. Going to Cat6 when they upgrade is a great suggestion. It will at least get them in the mode for future upgrades. Thanks again. This gives me some peace of mind that I am going in the right direction. >>> "Edward Ned Harvey" <lop...@nedharvey.com> 9/29/2010 8:54 PM >>> > From: tech-boun...@lopsa.org [mailto:tech-boun...@lopsa.org] On Behalf > Of John BORIS > > I am > looking > for some type of guide or spec that would say when it is best to use a > Home run to Network Center or to set up a Terminal Closet and have just > one (with a spare) run back to the Network Center. I don't think there's a two-word rule of thumb for this. It's a function of cost, speed, and distance. When the wiring folks come and hook things up, they'll generally charge per network drop (approximately) and the charge per drop will in part be based on the length of the run. Think of the cost as being modeled flat rate per drop + average length per drop. When the wiring folks provide an estimate or quotation for you, they're not going to measure every single length and apply a precise formula... They're going to guess and estimate. As far as cost is concerned, the best thing you can do is this: Provide a floor layout plan to the wiring folks, with marks & numbers indicating how many drops in which locations. Ask them if they think there is a cost benefit to multiple network closets. As far as speed is concerned ... Remember, if you have multiple closets connected via some sort of backbone, the backbone is a bottleneck. If you just need to provide basic internet to a bunch of peoples' laptops, probably no big deal. But if you have two datacenters on the floor with file servers or some other network-intensive application, communicating between each other, then maybe the speed bottleneck is a big concern. As far as distance is concerned... Roughly speaking, 100' or 200' or so is ok for a maximum length copper ethernet. Although the spec says something like 325, my experience says you're pushing it at 200'. The consequence of wire being too long is lost packets, burned out network cards, or no link. Be sure to account for indirect wire routing, around objects in the ceiling, etc, and overestimate the length by at least 20%. You can compensate in some cases, for long distances by using better-than-needed wires. For example ... I always use cat6, even if I'm only going to be running 10/100 or 1G. This is mostly a superstition on my part, and less scientific. Although you can run 1G over cat5e, the cost differential between types of cable is pretty negligible. If you need to cover more distance than that, you need a fibre run, which costs more. John J. Boris, Sr. JEN-A-SyS Administrator Archdiocese of Philadelphia "Remember! That light at the end of the tunnel Just might be the headlight of an oncoming train!" _______________________________________________ Tech mailing list Tech@lopsa.org http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
