On Tue, Jun 16, 2009 at 10:19 AM, Mikael Abrahamsson<[email protected]> wrote: > On Tue, 16 Jun 2009, FF wrote: > >> I thought Chromatic Dispersion is distance related. This is supposed > > Yes it is. > >> to be SMF-28 DSF, the optics are supposed to be 80km (XENPAK DWDM 1600 >> ps dispersion tolerance). Do you need a DCU even when operating within >> that range? One of the links is only about 40-50km. > > Well, you didn't say the links were DC or not, and you didn't say how long > the link was. At 40-50km, CD is most likely not the cause of your problems.
On the shorter link, we are seeing the same kind of problem, but not the same problem. Any traffic-related issues at that distance that could explain it? > > According to some info I found, SMF-28 DSF still has 17.1ps/nm/km, meaning > your 1600ps dispersion tolerance only gets you 94km? I might be wrong > though, I can't get the whole article, google only displays from its cache. Well, that could explain the longer link, definitely. Is dispersion something, say I'm +300 ps over my dispersion budget, I get a -625 ps DCU on each side and I'm good? I'm trying to avoid upsizing the amplifiers to compensate for the DCU's insertion loss. > >> Is there a Cisco command to pull up the BER the optic is seeing? > > No, on GE you can only see it by sending traffic and observing the error > counters. > Thank you very much. -- FF _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
