Packet over SONET failback

Per Carlson pelle at hemmop.com
Mon Feb 14 13:12:16 UTC 2011


Hi Jason.

>>> PoS failure detection happens in under 50ms

IMHO this is the most important part, fast *down* detection.

> It's not actually SONET all the way through.  It's GigE from the router to the SONET node, an unprotected OC192 wave to another node, out GigE to the far end router.

If the gear manages to shut down the GE lasers within the 50ms, you
have no rights at all to complain :-)

> I'm not necessarily talking about forwarding of packets here, I'm talking simply about the time it takes the far side interface to come back up over a SONET node; layer 1.  Maybe this has nothing at all to do with SONET, I dunno :)   It was gleaned that the next step might be to look at the SONET node and see if it's waiting 15 seconds to turn the laser back on or something.

A 15 second wait before enabling the path is a good thing. Nothing
worse than switch back to a path and experience a second down event
(and thrid, forth etc.). If it's been up 15 secs, it probably is safe
to use.

-- 
Pelle

RFC1925, truth 11:
 Every old idea will be proposed again with a different name and
 a different presentation, regardless of whether it works.




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