Range using single-mode SFPs across multi-mode fiber
Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters. We successfully established a 1G ethernet connection. Testing to date has been meager, but shows that the link is viable. Under significant load there is some minor packet loss. Since the link far exceeds the amount of data it required, we have decided to continue using it. Interestingly neither interface showed any physical errors. v/r, Oliver Rothschild Network Engineer III
On Wed, Dec 14, 2011 at 10:02:58PM -0500, oliver rothschild wrote:
Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters. We successfully established a 1G ethernet connection. Testing to date has been meager, but shows that the link is viable. Under significant load there is some minor packet loss. Since the link far exceeds the amount of data it required, we have decided to continue using it. Interestingly neither interface showed any physical errors.
Technically you should be using offset-launch "mode conditioning" patch cords at each end when running LX over multimode fiber. I had been lucky with not using them for many years on 62.5/125 (OM1) multimode (and just started doing so again, albiet only for OOB/non-production traffic use). I believe my longest link was/is around 1 km. http://www.cisco.com/en/US/prod/collateral/modules/ps5455/white_paper_c11-46...
2011/12/14 oliver rothschild <orothschild@gmail.com>
Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters.
How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
On 15/12/11 16:38, Keegan Holley wrote:
2011/12/14 oliver rothschild <orothschild@gmail.com>
Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters.
How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
Um.. check that. https://en.wikipedia.org/wiki/Multi-mode_optical_fiber "Typical transmission speed and distance limits are 100 Mbit/s for distances up to 2 km (100BASE-FX <https://en.wikipedia.org/wiki/100BASE-FX>), 1 Gbit/s to 220--550 m (1000BASE-SX <https://en.wikipedia.org/wiki/1000BASE-SX>), and 10 Gbit/s to 300 m (10GBASE-SR <https://en.wikipedia.org/wiki/10_Gigabit_Ethernet#10GBASE-SR>)." The old OM1 installations I used to work on started out as 10Mbit hubbed ethernet links and on the odd occasion would run out to close to 2km within a campus. They were progressively upgraded with the flow of: 10FX on 3Com Linkbuilder Kit 100FX on 3Com Corebuilder Kit and Allied Telesyn 100FX Media converters 1000SX on a variety of 3Com, Nortel and Cisco kit out to ~220m 1000LX via Mode-Conditioning out to ~900-1000m. The OM1 only got retired when the distance was >900m or there was budget to put new fibre on the run, in which case we ran SMF and rigged LX drivers. Mark.
I stand corrected, but I haven't dealt much with 100BASE-FX. I was just talking in terms of 1G/10G. 2011/12/14 Mark Foster <blakjak@blakjak.net>
On 15/12/11 16:38, Keegan Holley wrote:
2011/12/14 oliver rothschild <orothschild@gmail.com> <orothschild@gmail.com>
Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters.
How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
Um.. check that.
https://en.wikipedia.org/wiki/Multi-mode_optical_fiber
"Typical transmission speed and distance limits are 100 Mbit/s for distances up to 2 km (100BASE-FX<https://en.wikipedia.org/wiki/100BASE-FX>), 1 Gbit/s to 220–550 m (1000BASE-SX<https://en.wikipedia.org/wiki/1000BASE-SX>), and 10 Gbit/s to 300 m (10GBASE-SR<https://en.wikipedia.org/wiki/10_Gigabit_Ethernet#10GBASE-SR> )."
The old OM1 installations I used to work on started out as 10Mbit hubbed ethernet links and on the odd occasion would run out to close to 2km within a campus. They were progressively upgraded with the flow of:
10FX on 3Com Linkbuilder Kit 100FX on 3Com Corebuilder Kit and Allied Telesyn 100FX Media converters 1000SX on a variety of 3Com, Nortel and Cisco kit out to ~220m 1000LX via Mode-Conditioning out to ~900-1000m.
The OM1 only got retired when the distance was >900m or there was budget to put new fibre on the run, in which case we ran SMF and rigged LX drivers.
Mark.
On Wed, Dec 14, 2011 at 10:38:47PM -0500, Keegan Holley wrote:
2011/12/14 oliver rothschild <orothschild@gmail.com>
Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters.
How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
In my case, it was installed for compatibility with FDDI, and used mostly for 10BASE-FL and 100BASE-FX, which work up to 1 or 2km, until we started using it for 1000BASE-LX.
Some idiot jumpered runs that existed between 3 different buildings. That person did not know about the 550m limit that we also follow. Sent from my iPhone On Dec 14, 2011, at 22:38, Keegan Holley <keegan.holley@sungard.com> wrote:
2011/12/14 oliver rothschild <orothschild@gmail.com> Thanks to all who responded to my clumsy first question (both on matters of etiquette and technology). The group I work with (we are a small project acting as a last mile provider) was in the midst of deploying this solution when I posed the question. We put the single mode Juniper SFPs (LX) on to a run of approximately 1670 meters.
How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
On Wed, 14 Dec 2011, Keegan Holley wrote:
2011/12/14 oliver rothschild <orothschild@gmail.com> How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
Legacy 10baseFL/100baseFX/FDDI can run fairly long distances over OM1. In the past I've run 100baseFX over OM1 runs with multiple cross-connects, out to about 2 km. jms
The max limit for 100 base FX (100 Mbps Ethernet) is around 6600 feet. Many campus ductbank systems built in the 1990s when 10 and 100 Mbps Ethernet were the commodity speeds (before GiGE) used 62.5/125 MM fiber to connect buildings. It is not unusual to see long MM runs on campus facilities where 100 Mbps backbones once were the fastest speeds available. In those days, apart from longhaul telco use, singlemode fiber was usually only run for closed circuit TV (CCTV) use in the campus environment, and in places where 1990s SM was run for CCTV it can still be used for longhaul laser sfps, which to me shows that SM is future proof. SM even makes sense in short runs as attenuators can be placed on the send/receive strands to reduce the dB so the optical receiver is not saturated. -----Original Message----- From: Justin M. Streiner [mailto:streiner@cluebyfour.org] Sent: Thursday, December 15, 2011 5:53 AM To: Keegan Holley Cc: nanog@nanog.org; oliver rothschild Subject: Re: Range using single-mode SFPs across multi-mode fiber On Wed, 14 Dec 2011, Keegan Holley wrote:
2011/12/14 oliver rothschild <orothschild@gmail.com> How did you end up with a MM run this long? SX optics are only rated at 500 meters at best. Even with mode conditioning jumpers more the 1km is a risk. I'm glad it held up during testing though. Just out of curiosity did you purchase dark from a provider? Is it inside of a building?
Legacy 10baseFL/100baseFX/FDDI can run fairly long distances over OM1. In the past I've run 100baseFX over OM1 runs with multiple cross-connects, out to about 2 km. jms This communication, together with any attachments or embedded links, is for the sole use of the intended recipient(s) and may contain information that is confidential or legally protected. If you are not the intended recipient, you are hereby notified that any review, disclosure, copying, dissemination, distribution or use of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by return e-mail message and delete the original and all copies of the communication, along with any attachments or embedded links, from your system.
participants (7)
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Chuck Anderson -
Holmes,David A -
Justin M. Streiner -
Keegan Holley -
Mark Foster -
oliver rothschild -
Oliver Rothschild