New Fiber pull - Legacy equipment

[Keith Abbott]

Hi,

Mr Timmermans msg about 10g considerations raised some questions for me and rather than hijack his thread I'll start a new one.

We are getting ready to pull some additonal fiber into a distrib closet to support some growth in that area. We currently have 62.5/125mm 200/500 pulled into the closet, and the closet houses 3560 switches.

Our dilemma is that we would ideally like to pull for the future and pull something that will support 10g in case we need to upgrade the switches and go 10g to the closet in th future, but we need to support the current 1g links to the 3560's for the present. The run is nearly 300'.

What options do we have here for the fiber pull. According to the link in Mr. Timmermans thread

(http://www.nbm-distribution.co.uk/docs/10G_over_legacy_fibre_WP.pdf)   regarding 10G over legacy, it looks like our distance of about 100m is well inside the limit for OM1 for 10GBASE-LRM standard.  Can we just continue pulling the 62.5/125 and we will have support for 10G in the future? Or is there something else we should start pulling, that can continue to support our current equipment, but would be better for transitioning to 10g in the future?

Thanks for your input!

[PETER EIJSBERG]

You can use OM3 multimode fiber for 10G using the LRM modules without problems up to 100m or even more. When the fiber is OM1 you will need special patch cords - I would avoid that.

Peter

[Keith Abbott]

Hi Peter,

Thanks for the response.

The OM3 sounds good for the 10G, but what about supporting the current 1G links? I believe the OM3 will be 50/125mm whereas our current is 62.5/125. Will need need different terminations/connectors/patch cables and/or different SPFs for our 3560s to support the 50mm?

thanks

[PETER EIJSBERG]

Hi Keith,

You can run GigEth across 50um multimode fiber without problems. You're supposed to use 50 um patch cords, but I have done it with 62.5um patch cords and that works fine. Cisco documentation on SFPs and the fibers they support is here:

http://www.cisco.com/en/US/partner/prod/collateral/modules/ps5455/ps6577/product_data_sheet0900aecd8033f885.html

Peter

[Keith Abbott]

Hi Peter,

Thanks for the information.

Is anyone else using the 62.5mm patch cables with 50mm fiber? Are you also running with no probs?

Seems like there shouldnt be a problem for the gig uplinks since we're running 62.5 all the way through now with no problems, but just want to double-check.

Thx