With today’s stringent loss budgets and space constraints, some data centers choose to deploy MPO-to-LC hydra cable assemblies rather than LC duplex patch cords. However, there are some key factors to consider.
Hydra assemblies typically feature one 12-fiber MPO connector on one end that fans out to 6 duplex LC connectors (or 4 for 40G) on the other. They allow for connecting directly from MPO patch panel systems to the LC interface on active networking or SAN equipment. This essentially eliminates the need to use MPO-to-LC cassettes, which removes an LC connection point from the channel for reduced loss.
Hydra assemblies can also help alleviate space constraints in dense fixed environments, enable fast deployment at the switch and enable easier upgradability from 10G to 40G or 100G with no need to replace MPO-to-LC cassettes with MPO frames. All that would be needed to upgrade from a cabling standpoint are MPO patch cords.
Patch cords are supposed to be the most sacrificial components in the channel, and due to constant manipulation, they are also the component most apt to need replacing.
The biggest concern with using hydra assemblies is downtime. If one of the duplex LC fanouts fails or gets damaged, the entire hydra assembly needs to be replaced. And then instead of taking down just one switch port, all 4 or 6 switch ports will be down during maintenance.
On the contrary, if MPO-to-LC cassettes and LC duplex patch cords are deployed for switch connections and a patch cord fails, only one switch port goes down during maintenance.
First of all, the difference in cost between using MPO frames with hydra cables and MPO-to-LC cassettes with duplex LC patch cords is negligible. However, the cost of taking down 4 or 6 switch ports could mean the potential for plenty of money lost in downtime, depending on the application.
And the concern about loss is really a nonissue with today’s low loss fiber connectivity. For example, with Belden’s FiberExpress system that offers the lowest maximum insertion loss of just .15 dB for OM4 LC connectors and .2 dB for OM4 MPO connectors, you can have a 5-point topology with maximum reach for 10G, 40G, 100G and Fibre Channel. This scenario allows for having both a cross-connect and zone distribution area (ZDA) within the channel for maximum flexibility, scalability and security.
While downtime is a consideration with hydra cable assemblies, and today’s lower loss values means you likely don’t need them, there are still always going to be those data center managers that prefer the look and space savings of the hydra.
The good news is that Belden’s experts are ready to support your specific needs. We offer low-loss LC duplex patch cords and low-loss hydra cable assemblies, as well as low-loss MPO patch cords for when it is truly is time to migrate to 40 or 100 gig.
Dwayne Crawford has more than 20 years of experience in the datacomm industry. He has served on several international standards committees to advance high-performance/low-latency protocols (such as IEEE-1394, GigE Vision and CameraLink) used in real-time image processing and utilizing high-performance computing platforms.