At 01:31 PM 8/24/2004 -0700, Lane Patterson wrote:
Yes, you have experienced what is known in the field as "air gap attenuation"--not something you want to depend on if you want a clean link! A close relative is "knot-in-the-fiber attenuation".
a close relative of "who-pulled-this-fiber-anyway" ?" yes .. a kink ..a slight kink can do much loss .. easy to hold a fiber around your finger w/a meter attached and watch the atten .. as you bend the fiber ..
Your subject says "GigE Media converter" but you say you are deploying an OC12. Which is it?
I wondered that also ..
Definitely invest in a light meter that can do the usual flavors of single and multimode, connector types, and at least 850 and 1310nm wavelengths. Then simply test strength of light on your receive port
I'd go w/a test set if you afford it. It'll serve more than purpose and you'll get more use of it ..
on each side, compare to specifications of your equipment, and add in-line attenuators as necessary. You'll usually find a range something like -3 to -27 dBm, and we prefer -15 dBm as our ideal. Also, make sure you've got the right type of fiber jumpers--mixing up single (yellow) and multi (orange) mode fiber can cause similar issues.
Can't wait until more routers start to incorporate inline optical power readings in "show interface" commands the way Procket did :-)
some flava's of the GSR will show/report this .. under show controller but cisco says it's +_ 5 dbm .. they say .. ' You want a router or a meter ? " I have to agree .. would want not the expense of this added in. POS3/0 SECTION LOF = 0 LOS = 0 BIP(B1) = 0 LINE AIS = 0 RDI = 0 FEBE = 0 BIP(B2) = 0 PATH AIS = 5 RDI = 6 FEBE = 387 BIP(B3) = 6389 LOP = 5 NEWPTR = 0 PSE = 0 NSE = 0 Framing: SONET APS Optical Power Monitoring Rx optical power in mWs and dBms Port 0 = 0.02 mW, - 15.738 dBm Tx laser diode forward bias current I(F) in milliamps Port 0 = 18.009 mA Clock source: line
Cheers, -Lane
On Tue, Aug 24, 2004 at 01:10:15PM -0400, kwallace@pcconnection.com <kwallace@pcconnection.com> wrote:
2 quick things come to mind-
single mode vs multimode, or the signal is too hot and you need
attenuators.
-----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] Sent: Tuesday, August 24, 2004 12:48 PM To: nanog@nanog.org Subject: Weird GigE Media Converter Behavior
Hello all, wondering if anyone has seen or experienced this same problem. Currently deploying an OC12 on a campus network and am using Netgear media