[c-nsp] Long range 10G ethernet?

[Nick Hilliard]

On 16/05/2012 10:18, Peter Rathlev wrote:
> Now we're thinking about making it a 10G link instead. Finding 10G
> transceivers capable of supporting at least ~24-25dB seems tricky
> though.

have been there and done this.  I would recommend getting external
transponders for this, and if you are, to look into getting coloured
transceivers instead of grey 120km units (not even sure if they make grey
120km transceivers), because

- getting long range wdm X2 transceivers is likely to be very expensive
because only vendor C uses X2, and everyone else in the world uses XFP or SFP+.

- if you ever move to another platform, you can be pretty much guaranteed
it won't support x2, which means that your expenditure on x2 transceivers
will become worthless

> 2) We might cut ~1dB by splicing in a few places instead of patching,
> but we probably can't get below 23dB loss. Would using 25dB capable
> transceivers on a 23dB stretch be too bold for comfort?

yes.  This sounds like the sort of link where you'll have to add in a
couple of dB overhead to compensate for chromatic dispersion @10G.

Nick