Re: Qwest desires mesh to reduce unused standby capacity

On Thu, Feb 28, 2008, Joe Abley wrote:
> 
> 
> On 28-Feb-2008, at 01:56, Paul Wall wrote:
> 
> >UU/MFS tried running IP on the 'protect' path of
their SONET rings  
> >10 years ago. It didn't work then.
> 
> Well, it works so long as whoever was trying to
troubleshoot the  
> circuits at 3am on US Thanksgiving understands that
having the system  
> "switch to protect" is quite bad, in the
sense that it causes both  
> sides to go down at once (I seem to remember there was
a protect paths  
> built for each side of the original ring using a
loopback).
> 
> Other than the unfamiliarity with the concept
demonstrated by phone  
> companies, I didn't notice any great fundamental
problem with the  
> idea. The extra 10G of capacity across the Atlantic was
arguably more  
> useful in the grand scheme of things than the being
able to recover  
> from a single-point failure at SONET speeds. It's
probably fair to say  
> there's more real-time traffic on the network today
than there was  
> then, however.

Then you probably haven't been on the ass end of a
continental fibre link
drop. That actually mattered.




Adrian

On 28-Feb-2008, at 09:26, Adrian Chadd wrote:

> Then you probably haven't been on the ass end of a
continental fibre  
> link
> drop. That actually mattered.

If both sides of your SONET ring drop, then surely you're as
dead in  
the water as you would be if each side of the ring was being
used as a  
separate, unprotected circuit.

(But quite possibly I'm missing your point.)


Joe