[j-nsp] Do the old M-series fixed optic SONET/SDH PICs wear out?

[Tom Storey]

show int diag optic <interface>

Some interfaces don't support it as mentioned, e.g. the fixed optic
STM-64/OC-192 PICs in my experience. Otherwise I haven't come across a PIC
that takes pluggable optics that this didn't work on, as long as the optic
supports DOM I guess.

On Friday, 21 March 2014, Keegan Holley <no.spam at comcast.net> wrote:

>
> On Mar 14, 2014, at 5:06 PM, Will Orton <will at loopfree.net <javascript:;>>
> wrote:
>
> > I have a couple P(E)-4OC3-SON-SMIR that I purchased used and
> successfully ran in a
> > production network in the 2007-2009 timeframe. Then, about 5 years ago
> the OC3
> > links were taken out of service and the PICs sat in their routers (an
> M10 and an
> > M20) for 4-5 more years doing nothing.
> >
> > The ports were set "disable" but the PIC was online, so I believe the
> optical
> > transmitters were still active.
>
> Could just be dust/debris even if someone put the boots back on, which
> sometimes doesn’t happen.  SMIR is very sensitive dirt.
> >
> > Now I'm trying to reussurect them for lab use and I cannot for the life
> of me get
> > them to link up back-to-back. Only one port out of eight will even go
> "green" when
> > looped to itself with a 1m patch cable. None will link port-to-port.
> >
> > LOL clears and I get PLL lock, but then either LOS or LOF, AIS, BERR,
> etc on
> > both sides.
> >
> > I've tried:
> > -multiple patch cables (yes they're SMF)
> > -cleaning the cables' SC connector with tissue/alcohol
>
> This is a bad idea.  You could replace tiny dust particles with giant
> tissue fibers twice as big but still too small to see.  A proper fiber
> cleaner is about $100.  If you don’t have access to one you should just
> replace cables.
>
> > -blowing canned air into the ports on the PIC
>
> Bad idea as well. You’re actually more likely to blow things into the
> connectors than away from them.
>
> > -5 & 10db optical attenuators in case it was rx overload even though that
> > shouldn't matter
>
> I’ve never had to attenuate in a lab even with SMIR optics and 1-2m
> cables, but YMMV.  To quote my old SE, “Juniper likes it hot!”.
>
> > -verifying tx/rx strands and swapping just in case
> > -every combination of clocking,enable/disable scrambling, crc16/32, etc
> > -JUNOS 10, 11, and 12 in both M10 and M20 with FPC-E
> are you sure the new code is compatible with those cards?
>
> Are the optics swappable? I can’t remember for that card.  I’d try new
> ones or at least try known good ones in all the non-working ports.
>
> >
> >
> > Unfortunately I don't have a light meter. But I'm starting to think the
> > transmitters might just be toast and not pushing enough light to present
> a
> > usable signal to the other end even with only a 1m patch.
>
> You do actually have a moderately accurate light meter.  There’s a command
> that will show you light levels from the perspective of the PIC IIRC.  I
> can’t guarantee that it is supported on hardware this old though so YMMV.
>  I believe it’s under the show interfaces physical hierarchy.  It should
> tell you what it’s transmitting, what it’s receiving and the minimum light
> level to establish a link.
>
> Over the years, I’ve also taken to simply taking the known good port and
> cable and plugging it into all the stuff that didn’t work.  I would
> sometimes end up with cables pulled through racks and other dodgy places
> temporarily, but I always ended up invalidating some of my deductions.
>
> >
> >
> http://www.juniper.net/techpubs/software/junos/junos85/swconfig85-network-interfaces/id-12763130.html
> >
> > says:
> >
> > "To extend the life of the laser, when a SONET/SDH PIC is not being
> actively used
> > with any valid links, take the PIC offline until you are ready to
> establish a link
> > to another device. To do this, issue the request chassis pic offline
> fpc-slot
> > slot-number pic-slot slot-number operational mode command"
> >
> > Is this a real thing? Is 10-15 years in the expected usable lifetime of a
> > circa-2001 1310nm laser?
>
> Yes. no. maybe. probably. definitely.  sometimes…   I’ve seen gear used
> well beyond it’s expected lifetime and I’ve seen things come out of the
> depot completely unusable.  Everything breaks.  Stuff is either broken or
> not broken yet.  That’s why hardware lifecycle’s were invented.  If there’s
> no current in the components they will last longer at least according to
> the laws of physics.  That doesn’t mean that leaving one on for 5 years
> will definitely fry it.
>
> >
> >
> > -Will Orton
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