Your people will need to come to grips with the fact that just being able to see light coming out the end of the fiber is no longer sufficient. Depending on the length you will have to deal with Chromatic Dispersion and compensation for that. People will need to understand that waves that are coming into a filter at -3 will totally blow out waves coming in at -15, especially when EDFA (amps) are concerned. DWDM (in the metro instance) is all about light levels and making sure that all waves are within 3-5db of each other as they go from site to site. Also documentation of exactly which waves are used on each part of a path and management of your waves is important, especially to the NOC when troubleshooting or determining exactly everything that's affected when a path or wave goes down. Also fiber cleanliness and proper handling becomes really important. With 850nm and SMF you can pretty much lick the end of it and it will stick work fine. When running 20 lambdas over 50km it becomes a much bigger issue. I would recommend investing in good fiber cleaning/scoping gear and proper training for your physical plant folks. Also invest in a couple of decent OSA's to check levels of all waves coming off a fiber. You don't have to drop $80k (or lots more) on gear, but you'll need something capable of determining the power of different waves at once and checking for noise. JDSU, EXFO, and Fluke make some good gear and should have options to meet just about whatever your budget is. An OTDR is nice to have but not crucial, whoever is leasing you the fiber should be able to provide OTDR shots and characterization of the paths. Normal light level checking at various points should be able to provide you enough info to determine whether its your gear or the long fiber. With fixed wave gear you can start pretty cheap and build a decent enough system. If you're making lots of moves/add/changes all the time, I'd recommend tunable optics, especially for sparing. Then move to ROADM gear if needed. For the most part if your system is fairly static once you get it up and going you don't have to touch it much, it just works. The things that then change are when fiber is cut or stretched due to weather conditions or backhoes. The gear is pretty stable. Hope that helps a little bit. Enjoy! --chip On Fri, Nov 2, 2012 at 1:31 PM, Stefan <netfortius@gmail.com> wrote:
Looking at dark fiber leasing as an alternative for existing ISP-acquired MPLS, MetroE, P2P, etc. services. I would appreciate some pointers (links) into specific technologies used with dark fiber, as direct consumer (not ISP). I am not looking for the theory behind (C)DWDM, but rather real life implementations and experience with folks operating such.
Highly appreciated would also be extra info on what the learning curve required for traditional network engineering crew to operate devices terminating into such, and maybe even work (installation and operation) needed to maintain plants with this infrastructure.
TIA, ***Stefan
-- Just my $.02, your mileage may vary, batteries not included, etc....