Ummmm, the link is referring to *minimum* distances, not maximum. So 50
metres is not OK. However, the original poster did say 50m, not 50 metres.
If 50m was intended to refer to miles, not metres, you might be doing OK :
-)
Seems rather counter-intuitive - we usually have to worry about whether a
link is too long. But from my rather limited understanding, I think in
layman's terms if your link is too short then there will not be as much
power loss as 'expected', so you are at risk of frying your receiving
hardware.
JMcL
----- Forwarded by Jenny Mcleod/NSO/CSDA on 21/09/2001 02:06 pm -----
"Priscilla
Oppenheimer" To:
[EMAIL PROTECTED]
Subject: Re: how to test the GBIC
is
Sent by: 1000BASE-ZX. in GSR
[7:19114]
nobody@groups
tudy.com
21/09/2001
12:32
pm
Please
respond
to
"Priscilla
Oppenheimer"
Ummmm, he said 50 meters not 50 kilometers. 50 meters should easily be OK.
Priscilla
At 07:58 PM 9/20/01, David C Prall wrote:
> From the horses mouth:
>http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/6000hw/mod_inst/
>02prep.htm
>
>The minimum link distance for ZX GBICs is 6.2 miles (10 km) with an 8-dB
>attenuator installed at each end of the link. Without attenuators, the
>minimum link distance is 24.9 miles (40 km).
>
>With a 50m cable you should not be getting any kind of link and are most
>likely overdriving the Receive end.
>Therefore, when you do find a 40km long
>cable it may not work either.
>
>David C Prall [EMAIL PROTECTED] http://dcp.dcptech.com
>----- Original Message -----
>From: "Wang"
>To:
>Sent: Saturday, September 08, 2001 11:49 AM
>Subject: how to test the GBIC is 1000BASE-ZX. in GSR [7:19114]
>
>
> > Dear all :
> >
> > I 've are problem about testing cisco GBIC ZX in GSR. I just 've 50 M
> > single mode fiber.
> > Would you mind give me some information for test the GBIC.
> >
> > Story :
> > Our client 've order 3 GBIC for Three-port Gigabit Ethernet Card .
> > But, some problem in 2 GBIC can't pass connection test.
> >
> >
> > Test 1 )
> > I use the SC fiber cross at both GI port at e.g ( Gi2/0 to Gi 3/0).
> > The both 3GE-GBIC-SC status can not active & the all LED is off.
> > I 've try to sweep the TX & RX position and sweep to next Gigabit
> > Ethernet module..etc.
> > Still no response .
> >
> > Test 2 )
> > Next test, it test is use the one fiber cable only (single side). Make
> > the GBIC TX & RX in loop at single fiber. Just one GBIC can enable &
> > up. Other GBIC still is no response !
> > Remark : In this section the fiber have tested at both tx & rx is up.
> >
> > Our GBIC is 1000BASE-ZX.
> >
> > Following massage back from TAC:
> > ZX can reach about 70km, it is the most powerful one GBIC. Be sure to
> > use attenuator,
> > otherwise GBIC may be damaged by overpower level laser!!!
> >
> > In order to explain different performance from your 3 GBIC, I think we
> > can look at the tx
> > level of max 6db to min 0db. If the one tx 0db, certainly rx will
below
> > 0db. If the other tx
> > 6db, 50m fiber is not enough to cause 6db loss, so interface is still
> > down and GBIC may be
> > damaged.
> >
> > 9/125um SM 1000Base-ZX SC
> > 6 tx max
> > 0 tx min
> > 0 rx max
> > -23 rx min
> > 70 km 42 mile
> > 1000Base-ZX can reach up to 100km (60mi) by using dispersion shifted SM
> > or low
> > attenuation SM
> >
> > Regards,
> > Eric,
________________________
Priscilla Oppenheimer
http://www.priscilla.com
Message Posted at:
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