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Connecting Two Lx Port

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Oct 7th, 2005
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Hi All,

Can i connect two Lx ports in two different switches in the same room using a SC-SC Single mode fiber Patch cord ? Will i be getting any bit rate error?


R. Rajaraman

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glen.grant Fri, 10/07/2005 - 03:14
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It's possible you will get errors on that short of a run . If using lx on short runs you need a mode conditioning patch cable or the preferred method find 2 SX gbics .

amikat Fri, 10/07/2005 - 13:35
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The answer very much depends on which modules you are going to use. You need to check the optical power levels & budgets for the particular type. E.g. for Cisco 1000BASE-LX/LH modules both WS-G5486 (GBIC) and GLC-LH-SM (SFP) should work O.K. if they comply with Cisco data sheet specifications.

Best regards,


scottmac Fri, 10/07/2005 - 13:58
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If you connect two LX ports with a jumper, you *better* have some attenuation inline, or you risk seriously damaging the receiver in each of the transceiver modules.

How much attenuation? You need to look at the spec for the receiver, look at the spec for the transmitter, and make up the difference with an attenuator (or two or three ....).

Bit errors? Oh yes, you bet .... think about someone putting a kilowatt of audio next to your head and screaming directions to you through that system ..... do you think you'd hear them clearly?

Same thing ....


You are connecting systems made to drive a signal for many miles .... you have to drop the signal to make it look like it's gone through many many miles of media.

Good Luck



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