[c-nsp] LX vs. LH GBICs

[Matt Stevens]

I understand the whole LX/LH concept. I was more wondering what 
specifically the LX/LH GBICs report as their media type (LH?), and if 
there's an older part (or non-Cisco) part that reports LX.

Our connection to a cat65k reporting LH is working, whereas a connection 
reporting LX is not.

We've checked levels on this particular link, and everything looks 
within spec for both pieces of equipment - so I'm slightly grasping at 
straws. It's a remote site involving multiple vendors, so 
troubleshooting is painful to say the least.
-- 
matt


Richard A Steenbergen wrote:
> 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".
>