Sorry I didn't get back to you right away, My current full time job is caring for my 4 month old now that I am back from 15 months of active duty guards. I hope the below helps: > Hmm, this stuff was installed along time ago before my time here and I > know very little about fiber. Never fear fiber. Here is a short fiber primer: First of all I am going to assume only that you know that fiber transmits light and that is all, so please take no offense. Fiber works in much the same way as copper in data transmission, but how it is done is different and should be discussed in order to understand other aspects of it. Where copper uses the outside of the wire to transmit electrons by "handing" the electrons off from one copper atom to another, fiber allows the transmission of data by bouncing light off the inside of the glass fiber strand. The physics of this are not as important as the practical application of this knowledge. Fiber, like copper has a minimum bend radius that must NOT EVER be reached. Bending the fiber as well as rough handling causes micro fractures in the fiber and this degrades performance. From what you are saying, you want to increase your transmission rate on you network. This will require the fiber to carry many more flashes of light at a much faster rate. If you worked with Category 3 and Category 5 copper networking standards, you will recall that Cat 3 is only rated only to 16MHz or 10 Mbps where as Cat 5 is rated to 100MHz or 155Mbps or even faster. Both are made of copper, yet one transmits at a faster rate because it is constructed better. However, you can degrade Cat 5 to Cat 3 standards if you handle it roughly during install. Having it catch on something in its path and stretching, bending it back on its self, and even stepping on it can degrade it's transmission rates. Fiber is much more fragile and even with Kevlar wrappings and steel messenger lines inside the fiber package to improve strength, it still can be abused and made useless. The most important place to protect fiber is often the place where the least amount of protection occurs: Out of the bundle and into the switch/router/whatever. You can spend thousands of dollars on manufactured wire management (looks cool, works, but is usually overkill) or go to Menards and spend ten-fiddy on some fire rated conduit and manage/protect your exposed fiber. To figure the minimum bend radius of a fiber cable take the diameter of the cable bundle and multiply it by 10 for no load and by 20 when under load or pulling (i.e. Cable is 4.5 cm in dia. then 45 cm min bend radius +15 cm safety factor = 60 cm min bend) When I have installed fiber I have learned the hard way that you can be too forceful with it during install and termination. It requires a finesse as well as a knowledge of it's temperaments, err physical properties. > > I dont know how many fibers are in each wire. Is there some marking on > the wire I can look for that might tell me? Its orange :) hehe Yes, fiber is marked similarly to copper fiber. There should be OFxx where the OF is, yes you guessed it Optical Fiber and xx is the type of fiber such as NP for Nonconductive Plenum or CR for Conductive Riser to name a couple. There should be more numbers/letters after this that will tell you how many strands, the manufacture, distance in meters or feet, UL certification, and sometimes some other cryptic numbers (batch or production, etc). Email me the markings and I will try to make sense of them for you. > > All I know is that there is 4 physical pieces running under the alley. > Currently we are only using 2 of the wires, 1 pair. I think they work in > pairs? One for send and one for receive?! Is this what you are calling > multimode? O.K. It looks like you have 4 strand fiber running between your buildings. It is common practice to install extra fiber as the cost of installing far out ways the cost of fiber. In a basic fiber network you have two pairs. One send and one receive. In more complex fiber networks you will have primary and secondary pairs or failover pairs to create redundancy. The difference in single and multimode is cost, distance, and core size. Single mode is smaller in diameter (core size, not necessarily cable size), Is used for long distances, and is cheap. Multimode fiber has a larger core size to allow for several different frequencies of lasers to transmit at the same time. This allows for higher throughput and can be somewhat compared to multiplexing of voice communications. Multimode is great for intra-campus backbones and allows you to transmit several network segments (or greater bandwidth) over a single strand of fiber. > > I am told the other pair are backups. But if we could bond the two or > use both, we should just use them since they are run and unused. Seems > silly to just leave them sit there. If you use your backups you will network yourself into a corner as you will become dependant on fiber that is there to CYA. I would not do it. > > I am trying to learn more about this stuff. If anyone has any links or > other source of info that would be great. I learned all I know about fiber I learned from on the job training with my home town telecommunications company installing and terminating the "stuff" in commercial buildings. Here are some links that will help you, some of them I have used a few of them from time to time, others I just found and looked over and seemed O.K. http://www.iec.org/online/tutorials/fiber_optic/topic02.html http://www.ampnetconnect.com/ http://www.insltd.com/productlist.asp?CatID=2&bUnCat=4 http://www.tiaonline.org/ http://cablingdb.com/Glossary_of_Terms.asp http://www.anixter.com/ That should get you going. I haven't worked with fiber in a long time but used to install and terminated the stuff till my eyes boggled out. <shameless plug> I am looking for a job in networking/sys admin</shameless plug> > Thanks Eric! > > > Eric Ebner wrote: > >> Here is an option that is just really an upgrade from what you are currently >> using: >> http://www.transition.com/products/mcon_platform/standalone/gigabit/index.ht >> m >> >> You may want to see if you can push multimode over your fiber. If you need >> more bandwidth a upgrade from single to multi sometimes is the ticket, >> however can be expensive. >> >> How many fibers are in you wire? Two? Four? You may also want to look into >> segmenting your network, taking the computers that talk to each other the >> most at each building and placing them on a separate segment. >> >> Just some thoughts, let me know if you want more. >> >> Eric >> >> >> 23/12/2003 10:41, "Jason Jorgensen" <jasonj at igi.com> wrote: >> >> >> >>> We have fiber running between our 2 office buildings. On each end of the >>> fiber we have one of these devices to convert to ethernet >>> http://www.cdw.com/shop/products/default.aspx?ProductID=247614 >>> >>> Basically it looks like a fiber (BNC connections) to RJ-45 converter. >>> >>> We are pretty sure the fiber should support 1000base with no problems. >>> So I am looking for a drop in replacement for the 100base converter >>> units. Or some local consultant or company we could get out here to put >>> new ends on the fiber for a non-drop in replacement converter. >>> >>> Other suggestions and comments welcome. _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list