Cisco gigabit module run on FO Multimode >1 km

Answered Question
Feb 14th, 2010

Dear,

can you help me what's cisco gigabit  module can run on FO multimode >1 km?

regards,

Lian

I have this problem too.
0 votes
Correct Answer by Giuseppe Larosa about 6 years 9 months ago

Hello Lian,

it is a limit due to a combination of speed modulation tecniques and attenuation.

It is not a choice of Cisco for its products.

you should deploy SM fiber in parallel with current MM fiber.

As a temporary fix you could think if you have more links FE over MM and to build a port-channel if you have free MM fiber already deployed.

Hope to help

Giuseppe

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Reza Sharifi Sun, 02/14/2010 - 18:52

edgar_pascal wrote:

Dear,

can you help me what's cisco gigabit  module can run on FO multimode >1 km?

regards,

Lian

Hello Lian,

For 1 km (1000 meter) you have to use a single-mode SFP

Here is part number:

GLC-LH-SM

This single-mode SFP supports up to 10km.

Multi-mode supports up to 550 meter only.

Here is the part number:

GLC-SX-MM

Also, here is the data sheet for all connectors.

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/hardware/Chassis_Installation/Cat6500/0bcabcon.html#wp1098140

HTH

Reza

edgar_pascal Sun, 02/14/2010 - 19:37

Hi Reza,

that''s the problem when i'm using uplink 100 mb via FO MM it's ok, but when upgrade to Gb be the problem.

can you help me to find another type / brand to run FO MM >1 km Gb speed.

Currently i'm using FO MM to all of my office.

Regards,

Lian

Reza Sharifi Sun, 02/14/2010 - 20:04

Hi Lian,

Correct, that is because 100MB MM SFP supports up to 2000 meter (2K) wether you use 50 or 62.5 micron fiber, but it does not support the same distance when you are using it with a Gig interface, therefore if you want to go up to 1000 meter (1K) you have to use single-mode SFPs with Gig interfaces.

How many SFPs we are talking about here?

The list price is:

$995 single-mode SFP

$500 multi-mode SFP

If you have single-mode fiber in place

HTH

Reza

edgar_pascal Sun, 02/14/2010 - 21:18

Hi Reza,

i aggre with you, but still not satisfied cause all my offcice more than 1km from the branch office.

Cause with this situation i must be replace my FO from MM to SM.

I have buy a lot of GLC-LH-SM but for FO MM more than 1 km still can run.

Do you have any idea.

Regards,

Lian

Jerry Ye Mon, 02/15/2010 - 08:29

The IEEE 802.3z 1000Base-SX specification said the maximum distance for 1GE MM is 550m. This is an industrial standard and the only option is to use SMF.

Matter of fact, with 10GBASE-SR (over MM fiber) is only 300m.

HTH,

jerry

Correct Answer
Giuseppe Larosa Mon, 02/15/2010 - 08:44

Hello Lian,

it is a limit due to a combination of speed modulation tecniques and attenuation.

It is not a choice of Cisco for its products.

you should deploy SM fiber in parallel with current MM fiber.

As a temporary fix you could think if you have more links FE over MM and to build a port-channel if you have free MM fiber already deployed.

Hope to help

Giuseppe

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