So much networking buzz revolves around 40G and 100G networking speeds these days, but we aren’t forgetting about the vast landscape of 1G and 10G networks.
If you’re building a new 1G or 10G fiber network—or expanding an existing one—there are plenty of things to take into consideration (media conversion being just one).
For your short-reach installations, you’ll have to contend with different optical multi-mode (OM) standards (OM1, OM3, OM4, OM5) and ensure you aren’t falling into the critical visibility pitfall—mismatched fiber core sizes.
The Fundamental Specs for OM1, OM3 and OM4 Fiber
Network architects might be comfortable with the relative simplicity and familiarity of copper gigabit networks with RJ-45 connectors. But the reality is that fiber is far more complicated and you can’t install it without understanding what fits your network. Here are the specs for OM1, OM3 and OM4 fiber that you need to know before undergoing any upgrades or new installations.
|
OM Type |
Fiber Core (in mm) |
Maximum Bandwidth (MHz*km) |
Link Length for 1G Networks (m) |
Link Length for 10G Networks (m) |
|
OM1 |
62.5 |
500 |
300 |
33 |
|
OM3 |
50 |
2,000 |
1,000 |
300 |
|
OM4 |
50 |
4,000 |
1,100 |
550 |
Source: American Fibertek Application Note, Practical Multimode Fiber Considerations
At first glance, it’s obvious that as you move down the list, performance improves. Even though some experts urge network architects to avoid new OM1 installations, the fact is that as of 2013, OM1 fiber accounted for over 25% of North American multimode fiber sales. These multi-mode fiber types are coexisting and 1G and 10G networks, leading to a critical pitfall for network architects.
The differing fiber core sizes (62.5 micron for OM1 and 50 micron for OM3/OM4) can cause severe optical loss if not handled correctly. Don’t fall into the critical pitfall.
Why You Can’t Mix-and-Match OM1 Fiber with OM3/OM4 Fiber
Knowing whether you’re connecting 62.5-micron or 50-micron fiber in your network is essential to ensuring total visibility. It might seem obvious, but connecting a 62.5-micron OM1 fiber to a 50-micron OM3/OM4 fiber means the core sizes don’t match and light transmitted from the OM1 fiber will be lost as it floods the 50-micron core.
You shouldn’t connect a 62.5-micron network component with a 50-micron component; but there’s another layer to the issue when network TAPs are introduced.
Your network TAPs must also match the fiber core size in your network. We’ve seen customers purchase a whole set of network TAPs only to find that the solutions were built to support 50-micron OM3/OM4 fiber—not the larger OM1 fiber. Connecting 62.5-micron fiber from network elements simply dropped packets and defeated the purpose of deploying network TAPs.
The bottom line: Before you purchase your network TAPs, check and see which fiber core size you’re dealing with. When you know you have OM1 or OM3/OM4/OM5 fiber to TAP, you can purchase the correct visibility solutions and ensure your appliances see every bit, byte and packet® of traffic.
Ensuring 100% network visibility is about much more than just OM fiber matching.
Looking to add fiber TAPs to your next deployment, but not sure where to start? Join us for a brief network Design-IT consultation or demo. No obligation - it’s what we love to do!
