10 GB GBIC Question

[jim_berlow]

In our environment we only have 62.5 micron MMF and want to run 10 GB. Some of our IDFs where we want 10 GB is about 100M away. I know this isn't an ideal design, but I have 2 questions. Is it possible to use the Cisco SFP-10G-LR on both sides of a MMF run and will it extend the distance any?

Thanks for your help,

Jim

[viyuan700]

Is it possible to use the Cisco SFP-10G-LR on both sides of a MMF run and will it extend the distance any?

Hi Jim,

SFP-10G-LR is for single mode fiber and 10Km but you WILL NOT GET 100m if you this module over 62.5 MMF.

You have 2 options

1. Use any single mode fiber with SFP-10G-LR. If possible to lay.

2. Use instead Cisco X2-10GB-LRM if it is compatible with your system but you need to buy mode conditioning patchchord with this. This module is also single mode laser but it can go over MMF with mode conditioning patchchord and you get distance of 220m.

see this link

https://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6574/product_data_sheet0900aecd801f92aa.html

You can compare the cost and feasibility. If you have any single mode fiber or can lay then i think will be a cheaper solution.

[Tom Randstrom]

The problem with running a standard 10G-LR signal over older 62.5um fiber is dispersion of the optical signal. The far end receiver cannot read the bits correctly. The 10G-LMR spec was created to add dispersion compensation to the optical receivers, enabling them to correct for the fiber's dispersion and read the bits correctly.

If you have a switch available that uses Xenpak optical modules, you could use one of the following solutions to reach 100M:

Cisco XENPAK-10GB-LRM:

Supports link lengths 220m on standard FDDI-grade multimode fiber (MMF). To ensure that specifications are met over FDDI-grade, OM1 and OM2 fibers, the transmitter should be coupled through a mode conditioning patch cord.

Cisco XENPAK-10GB-LX4:

Supports link lengths of 300m on standard Fiber Distributed Data Interface (FDDI) grade multimode fiber (MMF). To ensure that specifications are met, the transmitter output should be coupled through a mode conditioning patch cord.

Hope this helps!

[viyuan700]

Just a small correction,

The problem with running a standard 10G-LR signal over older 62.5um fiber is dispersion of the optical signal.

Main problem is not dispersion but DMD (Differential MOde Delay). If i use simple language when you launch a single mode laser into MMF, you get many copies of the same signal at different time (Here Problem of many mode is more than Dispersion) so receiver is is confused.

To reduce the number of modes they use mode conditioning patchchord and then LRM receiver use a EDC (Electronic Dispersion Compensation not same as Optical Dispersion Module) to reduce ISI (if still there is more than one copy of signal)

For more detail see (If you have not seen earlier)see the first paper A4_White_Paper_MASTER.qxd

http://www.gocsc.com/search/search.asp

[jim_berlow]

Thanks guys - this is all really good information. Just one more question.

On one side of this link I have 6500s where I can deploy either XENPAKs or X2 Modules. On the other side of the link I have a Nexus 7000 where it looks like the 32 port 10 GbE module only supports SFP+.

So I'm trying to find a compatible SFP+ module and XENPAK / X2 that can run on MMF (62.5u). It looks like I am really limited on the Nexus side. Any ideas on what modules to use to utilize the existing 62.5u MMF already installed?

Thanks,

Jim

[viyuan700]

Hi Jim,

I think you ar not only limited to NExus side if you see compatibility matrix 6500 dont support SFP+ bu they can work with Xenpak

http://www.cisco.com/en/US/docs/interfaces_modules/transceiver_modules/compatibility/matrix/OL_6974.html

In my opinion SFP+ module SFP-10G-LR should work with Cisco X2-10GB-LRM (U can check with cisco before ordering). U need 2 mode conditioning patchchord also.

Check this link about SFP+ where it mention

"Optical interoperability with 10GBASE XENPAK, 10GBASE X2, and 10GBASE XFP interfaces on the same link

"

http://www.cisco.com/en/US/prod/collateral/modules/ps5455/data_sheet_c78-455693.html

[Kim Wall]

Hello Jim. I have a similar situation and was wondering if you were able to get this working with mode conditioning patch cables.

Thanks,

Kim

[viyuan700]

If you have already have SFP-10G-LR and if you can arrange 2 Mode conditioning patchchord. Connect it and check if that works.

I am not 100% sure whether it will work or not. So asking to experiment if you think it makes sense to try.