The benefits of automating fiber interconnects in data centers are obvious. Automation can reduce operational expenses, eliminate human error, speed up service offerings, and improve efficiency. However, roadblocks have included both technological and operational challenges. Any automated system must meet the performance standards of manual patch panels (low optical loss, latching and ability to scale) while offering a simple execution path that minimizes the initial investment while preserving the interconnection flexibility across connected elements both initially and as the need for interconnection grows. A new RobUST approach by Telescent combines the low cost and simplicity of manual patch panels with the long-term benefits of automation to create an attractive approach that lets MTDCs and fiber network operators build for today with a design ready for tomorrow.
The challenges of automation can be illustrated with an example use case in a multi-tenant data center (MTDC). Since it is much easier to install fiber from the customer cages to the meet-me-room during construction, leading MTDCs often pre-wire with fiber cable bundles. In addition to simplifying installation, this also allows the MTDC to offer faster service than running “home-run” connections with each interconnection request, particularly if the end-points are on different floors or data halls. With a large part of the cost being the labor to install the fiber, it makes economic sense to install a larger fiber bundle than initially needed. When this extra capacity is added across the entire data center with many customer cages, there will be a lot of unused fiber at the beginning of the data center life that needs to be terminated on patch panels. Since any one of the customers may order a new cross connect at any time, if the meet-me-room is to be fully automated then all these initially unused fibers must be connected to the robotic patch panel and ready for interconnection. Since most optical cross-connect systems do not have a pay-as-you-grow model, this creates a very large up-front cost to build out an automated meet-me-room.
While there are other use cases for data centers and fiber-optic service providers, the requirements for automation include:
Low loss and latching performance to match the performance of manual patch panels
Low initial per-port cost for unused capacity of large-count fiber cables or pre-cablings
Ability to interconnect any port, not just a subset of “active” ports
Ability to easily scale from a few hundred to thousands of interconnections
Ability to test all ports to insure proper performance
Expand “on demand” to add interconnect capacity that matches revenue growth for the network
While interest in automating interconnects at data centers has been around for a decade or more, prior approaches to automation could not meet the above challenges. Optical cross-connect systems using MEMS or piezo-based actuators introduced optical loss of over 2 dB per connection and the system sizes were limited to at most a few hundred ports per system. Since these systems are also an enclosed unit, any component failure in the system requires replacing the entire system. These systems also failed open, meaning that with any power outage or internal system failure all the connections are lost, clearly an unacceptable outcome. These systems were fixed in port count, creating a significant up-front cost for implementation even if only a small number of ports would be used initially. To scale beyond the single system port count, they used a Clos leaf-spine network. Since Clos networks do not scale easily, these required a large up-front investment of spine nodes even when only a small number of interconnections were initially needed, further increasing the up-front costs for this approach.
Telescent has developed a robotic patch panel that can address the requirements from the use case listed above as well as a new RobUST approach to upgrade the robotic patch panel that offers a lower up-front cost for unused fibers while preserving the ability to connect any port when needed. The Telescent system is purely fiber-based, offering low loss and latchability that matches manual patch panel performance. When an add, move or drop is requested, the Telescent robot grabs the end of the fiber and weaves it around the other fibers in the system to the requested port. A key advance in the Telescent system is an algorithm that the robot uses to weave around the other fibers while avoiding any blocking or knotting. This preserves the ability of the system to make any connection request (i.e. non-blocking) while scaling to over 1,000 ports per system. Test equipment such as OTDRs can be included with the Telescent system to allow monitoring of any fiber when requested. The Telescent system has passed NEBS Level 3 certification as well as multiple customer certifications and has over 1 billion port hours in operation.
Since data centers or networks may not need 1,000 connections initially, the Telescent system has always offered a pay-as-you-grow design. The system includes a modular design where 96 port fiber modules can be added to the system at any time. These modules can be added without disturbing any of the existing interconnections (i.e. while running live traffic). After installation, the system offers any-to-any connectivity between original and newly added ports.
A new approach at Telescent to modularity goes one step further and allows the fiber modules to be added in 2 parts. This greatly reduces the up-front cost for implementation while preserving the ability to access any port for automation. With this RobUST approach of the Telescent system, the long-term benefits of automation can be realized with a low-cost and simple scaling approach for initial deployment. If you think your data center can benefit from automation, please contact Telescent today to learn more about our new RobUST approach to data center automation.