On 02.01.2010 02:10, William Herrin wrote:
On Fri, Jan 1, 2010 at 7:24 PM, ML <ml@kenweb.org> wrote:
Pardon my ignorance in this area but is too much to ask for OTDR data before signing contracts? In addition to data on the make of the fiber if you wanted to do xWDM in the future.
Yes, it's too much to ask. They won't splice your path until you sign the contracts and you can't get useful OTDR and loss readings until the fiber is spliced.
In my experience the fiber splice/patch-teams have quite accurate estimations on the overall attenuation of unprovisioned paths. They know the distance (0.25dB/km for G.652 @ 1550nm), the number of connectors (0.35dB per plug average here) and splices (0.1dB/spice). YMMV though. We add +20% safety, include an escape clause wherever possible and cross our fingers. With regards to suggested EDFA amplification tricks and similar: If the requirement is not > 150km@1G or 80km@10G/DWDM then I personally strongly disencourage the use of optical amps. 200km / 41dB 1G SFPs are available with costs way below dual EDFAs plus spare, and the chance for the untrained to get eye damages in the process of implementation is far less. So put some laser googles at around 400 USD/each to the purchase list. If one decides to do so then add a post-amplifier on each *end* of the fiber link to increase the signal before hitting the receiver, and do not pump in star-wars class laser power at the beginning ;) . Cheers, -- Rene Avi next layer Telekommunikationsdienstleistungs- und Beratungs GmbH Mariahilfer Guertel 37/7 | A-1150 Wien | FB 257486g | HG Wien tel: +43 664 31764 00 | fax: +43 517649 | web: www.nextlayer.at my layers: Fiber/Metro | D/CWDM | Cisco | Juniper | I/BGP | MPLS