RE: High Density Multimode Runs BCP?

[Scott McGrath <mcgrath () fas harvard edu>]

Hi, Martin

Yes indeed the ribbon cable.  Tho' due to the damage factor I probably
would not specify it again unless I could use innerduct to protect it as
we had some machine room renovations done and the construction workers
managed to kink the underfloor runs as well as setting off the Halon
system several times...


The ribbon cables work well if they are adequately protected.  If the
people in the machine room environment are skilled at handling fiber
there should be no problems.   If however J. Random Laborer has access I
would go with conventional armored runs.


                            Scott C. McGrath

On Wed, 26 Jan 2005, Hannigan, Martin wrote:

> The ribbon cable?
>
>
>
>
> --
> Martin Hannigan                         (c) 617-388-2663
> VeriSign, Inc.                          (w) 703-948-7018
> Network Engineer IV                       Operations & Infrastructure
> hannigan () verisign com
>
>
>
> > -----Original Message-----
> > From: Scott McGrath [mailto:mcgrath () fas harvard edu]
> > Sent: Wednesday, January 26, 2005 6:44 PM
> > To: Hannigan, Martin
> > Cc: Thor Lancelot Simon; nanog () merit edu
> > Subject: RE: High Density Multimode Runs BCP?
> >
> >
> >
> > Hi, Thor
> >
> > We used it to create zone distribution points throughout our
> > datacenter's
> > which ran back to a central distribution point.   This
> > solution has been
> > in place for almost 4 years.   We have 10Gb SM ethernet links
> > traversing
> > the datacenter which link to the campus distribution center.
> >
> > The only downsides we have experienced are
> >
> > 1 - Lead time in getting the component parts
> >
> > 2 - easiliy damaged by careless contractors
> >
> > 3 - somewhat higher than normal back reflection
> >     on poor terminations
> >
> >                             Scott C. McGrath
> >
> > On Wed, 26 Jan 2005, Hannigan, Martin wrote:
> >
> > > > -----Original Message-----
> > > > From: Thor Lancelot Simon [mailto:tls () netbsd org]
> > > > Sent: Wednesday, January 26, 2005 3:17 PM
> > > > To: Hannigan, Martin; nanog () merit edu
> > > > Subject: Re: High Density Multimode Runs BCP?
> > > >
> > > >
> > > > On Wed, Jan 26, 2005 at 02:49:29PM -0500, Hannigan, Martin wrote:
> > > > > > > When running say 24-pairs of multi-mode across a
> > > > datacenter, I have
> > > > > > > considered a few solutions, but am not sure what is
> > > > > > common/best practice.
> > > > > >
> > > > > > I assume multiplexing up to 10Gb (possibly two links
> > > > thereof) and then
> > > > > > back down is cost-prohibitive?  That's probably the
> > > > "best" practice.
> > > > > I think he's talking physical plant. 200m should be
> > fine. Consult
> > > > > your equipment for power levels and support distance.
> > > >
> > > > Sure -- but given the cost of the new physical plant
> > installation he's
> > > > talking about, the fact that he seems to know the present
> > maximum data
> > > > rate for each physical link, and so forth, I think it does
> > > > make sense to
> > > > ask the question "is the right solution to simply be more
> > economical
> > > > with physical plant by multiplexing to a higher data rate"?
> > > >
> > > > I've never used fibre ribbon, as advocated by someone else in
> > > > this thread,
> > > > and that does sound like a very clever space- and
> > possibly cost-saving
> > > > solution to the puzzle.  But even so, spending tens of
> > thousands of
> > > > dollars to carry 24 discrete physical links hundreds of
> > > > meters across a
> > >
> > > Tens of thousands? 24 strand x 100' @ $5 = $500. Fusion splice
> > > is $25 per splice per strand including termination. The 100m
> > > patch chords are $100.00. It's cheaper to bundle and splice.
> > >
> > > How much does the mux cost?
> > >
> > >
> > > > datacenter, each at what is, these days, not a
> > particularly high data
> > > > rate, may not be the best choice.  There may well be some
> > > > question about
> > > > at which layer it makes sense to aggregate the links --
> > but to me, the
> > > > question "is it really the best choice of design
> > constraints to take
> > > > aggregation/multiplexing off the table" is a very
> > substantial one here
> > > > and not profitably avoided.
> > >
> > > Fiber ribbon doesn't "fit" in any long distance (+7') distribution
> > > system, rich or poor, that I'm aware of. Racks, cabinets, et. al.
> > > are not very conducive to it. The only application I've seen was
> > > IBM fiber channel.
> > >
> > > Datacenters are sometimes permanent facilities and it's better,
> > > IMHO, to make things more permanent with cross connect than
> > > aggregation. It enables you to make your cabinet cabling and
> > > your termination area cabling almost permanent and maintenance
> > > free - as well as giving you test,add, move, and drop. It's more
> > > cable, but less equipment to maintain, support, and reduces
> > > failure points. It enhances security as well. You can't open
> > > the cabinet and just jack something in. You have to provision
> > > behind the locked term area.
> > >
> > > I'd love to hear about a positive experience using ribbon cable
> > > inside a datacenter.
> > >
> > >
> > > > Thor