On Sun, May 13, 2001 at 12:41:17PM +0200, Hank Nussbacher wrote:
> The normal attenuation for single mode fiber is 0.33 dB/km, which means a
> distance of up to 70 km. However, in the table it is specified at 40
> km. Is this just Cisco being conservative?
Probably. They're not going to make any assumptions about the quality
of your fiber plant, for obvious reasons. In this particular case I'll
bet that dispersion is the limiting factor, not optical power. One
solution is to install some sort of 1310-1550 box at each end to get
the extra distance (dispersion characteristics are better at 1550nm
typically). I know of two vendors that make such a box, JDS Uniphase
and IPTEK. I can't find the IPTEK link right now but the JDSU product
is called the "WaveShifter" and you can get more info about it here:
AFAIK there isn't an NxOC3 card from Cisco that operates at 1550nm.
Good luck,
--Jeff
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:37 EDT