10 ways to build an uber-reliable Optical LAN for your always-on networking needs

by | Oct 4, 2022 | Blog

Protection and redundancy features of Passive Optical LAN

I’m writing this morning with no network connectivity. The internet has gone down, my work productivity is suffering, and I’ve learned this extended outage is due to a fiber cut. In the same service alert text stream, my network provider let me know that my monthly bill was due, and that I should pay it promptly!?!?

Service Outage Alert

As I wait for the network to be restored, I can use this downtime to write a blog about optimizing network uptime through the advanced protection and redundancy features of Passive Optical LAN.

High-performance enterprise LANs deliver real-time and critical services that demand high availability, stability and uptime. Tellabs Optical LAN is the optimal choice for modern enterprises because it provides superior reliability utilizing the following protection mechanisms:

  1. Dual Homing Routers – Let’s start at the core routers where the Ethernet network uplinks between the OLT and the core routers can be redundant. Here protection switching occurs over the redundant uplink connecting the core router by using standards-based Ethernet protocols.
  2. Chassis Based OLT Redundancy – There is an option for chassis-based OLT redundancy (e.g. Tellabs FlexSym OLT6) where duplex components including Ethernet Switch Units, common control, network uplinks, service module and/or whole OLTs, power plant and fans.
  3. Highly Reliable ONTs – Organically, ONTs are meant to operate with limited human touch and be low maintenance network edge devices. Their carrier-grade heritage ensures that they are simple, unmanaged, and thus highly reliable optical-to-electrical media converters.
  4. Simplified PON Management – Optical LAN’s centralized management reduce human error/misuse by promoting machine-to-machine actions and operational consistency. The PON manager’s global profiles and templates effectively eliminate human error from daily moves, adds and changes work.
  5. Port, Card and OLT Protection – FSAN ITU Type-B PON Protection can be utilized for port, card or OLT level protection. This is a purely passive protection solution (e.g. no in-band nor out-of-band communications needed) using dual feed 2:x optical splitters. These extremely reliable 2:x optical splitters require no power, no management nor maintenance.
  6. Fiber Route Diversity – Once you have Type-B PON Protection between the OLT and optical splitters, it is smart to separate the redundant fiber cables to protect against fiber cuts. In fact, we highly recommend implementing card, and OLT level redundancy, which results in the highest degree of network performance as well as protection.
  7. Geographically Dispersed OLTs – With redundant OLTs, best practice design is to place these two OLTs in geographically dispersed locations. This configuration provides system level backup against building power outages and catastrophic failures, which can be emergency situations that demand uninterrupted communication.
  8. PON Path Protection – Beyond ITU Type-B PON Protection, Tellabs uniquely provides PON path level protection where the system software proactively monitors the network Ethernet uplinks, and if it detects the OLT has lost connectivity to the network core (WAN uplink), it will automatically switch.
  9. PON Health Protection – Another unique Tellabs’ protection scheme, in addition to ITU Type-B PON Protection, is Tellabs PON Health Protection. Here the system software again proactively monitors the network health metrics via established threshold alarms, and if network degradation is observed, a switch will occur automatically.
  10. PON Diversification – Last, there is a method to design the placement of the 2:x optical splitters, fiber cabling, ONTs and the final Ethernet connections, in a manner that improves service level availability at the edge. That is, two nearby ONTs can be connected to two different optical splitters, and by inter-mixing the two ONT’s Ethernet drops, you effectively eliminate the possibility of widespread service outages deep in the enterprise.

There’s not much I can write to help you when your service provider network goes down. Yet, I have full confidence that with an Optical LAN design, and the 10 protection mechanisms outlined above, your enterprise network can experience industry leading uptime availability.

You can learn more by visiting our online resources for Optical LAN High Availability, and we always encourage you to join our social media channels, such as Facebook, LinkedInTwitter, Instagram, and YouTube.

Tellabs Optical LAN advanced protection design


John Hoover, Tellabs Marketing Director
John Hoover
Director of Marketing
John Hoover is a Marketing Director at Tellabs and 2024 Board Chair of the Association for Promoting Optical LAN (APOLAN). Over the past 20 years, John has influenced industry milestones such as early passive optical network deployments, video implementations, wireless and more recently enterprise Passive Optical LAN adoption.

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