Choosing Fibre cable

[mahesh18]

           Hi Everyone,

From Fibre Patch Panel to switch which is around 6 feets away which cable should we use Single mode  or Multi Mode?

I read that Multimode is used for shorter distances and can carry more data.

Or does it depend on type of GBIC which we use on switch side?

Office A side is

Switch  module is side is 18  1000BaseX (GBIC)                       WS-X4418-GB   

Gbic on port is 

Type:                  1000BaseSX

Office B  end switch port is

Type:                  1000BaseSX SFP

Both office is connected with fibre within  same building.

Thanks

Mahesh

[Reza Sharifi · Accepted solution]

Hi Mahesh,

According to your original post, both site-A and B are using 1000BASE-SX Gbics.  If this is the case, you have to use Multimode fiber with these Gbics.  You can't use Single mode.

Have a look at the diference below:

Cisco 1000BASE-SX GBIC

The  Cisco 1000BASE-SX GBIC (WS-G5484) operates on legacy multimode fiber  (MMF) optic link spans up to 1815 feet (550 m) and on laser-optimized  multimode fiber (OM3) optic link spans up to 3281 feet (1 km).

Cisco 1000BASE-LX/LH GBIC

The  Cisco 1000BASE-LX/LH GBIC (WS-G5486) fully complies with the IEEE  802.3z 1000BASE-LX10 standard. It allows for reaches up to 6.2 miles (10  km) over single-mode fiber (SMF) and up to 550 meters over multimode  fiber (MMF). Note the requirements for mode conditioning patch (MCP)  cords when coupled over legacy MMF: http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_bulletin_c25-530836.html.

More info:

http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6577/product_data_sheet09186a008014cb5e_ps872_Products_Data_Sheet.html

HTH

Reza

[mahesh18]

Hi Reza,

Do you  mean cable form Switch to Fibre patch panel right?

As both switches have these GBIC types

1000BaseSX?

Thanks

[Reza Sharifi · Accepted solution]

Hi Mahesh,

Yes, since your Gbics are Multimode (SX) your cable from the patch panel to the switch also needs to be multimode.

If your Gbics were single mode (LX) than you would need to use single mode cable from the patch panel to the switch.

HTH

Reza

[mahesh18]

Hi Reza,

I am surprised that Multimode GBIC  is working fine with single mode cable.

Any way i will swap cable with MM.

Thanks for putting the very useful info again.

Regards

MAhesh