[c-nsp] LX vs. LH GBICs

[Richard A Steenbergen]

On Fri, Mar 21, 2008 at 03:57:59PM -0500, Max Pierson wrote:
> 1000BaseLX/LH interfaces are fully comply with the IEEE 802.3z
> 1000BaseLX standard. However, their higher optical quality allows them
> to reach 10 km over single-mode fiber (SMF) versus the 5 km specified in
> the standard. This is where the LH kicks in...which allows them to
> achieve a longer distance when used with SMF.

But at this point every LX you're ever going to run across does 10km or 
better (often much better), and the use of the name "LH" is just a 
Ciscoism that only serves to confuse people. Also note that different 
vendors use the names differently, for example Juniper LH is a 70km 1550nm 
optic (what cisco calls ZX), which is different from its LX 10km 1310nm 
optic.

At any rate they're all compatible with each other, all RX units are 
wide-band, so as long as you aren't trying to engineer something 
complicated (with a filter, with concerns about dispersion, etc) your only 
real concern is "do I have enough optical budget" and maybe "do I need to 
attenuate".

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)