While there are many challenges to operating a multi-tenant data center (MTDC), such as managing power availability to ensure uptime and controlling temperature to protect the equipment, sometimes simple things can be some of the biggest headaches. When discussing the business problems of operating a large data center campus with the former CTO of one of the largest MTDCs, some of the issues at the top of the list were:
Fiber disconnects hog up cable trays,
Time to provision cross connects and
Ease of reprovisioning (speed, cost)
The challenge from fiber disconnects is that when a customer changes connectivity, such as changing service providers or moving to a cloud service, the old fiber is left in place while a new fiber is run from the customer to the new provider. The old fiber is left in place since the fiber trays are full and pulling the existing fiber out of the fiber tray risks displacing other fibers with active connections. So over time as new connections are made, the fiber trays fill up with more and more fibers. The problem is even worse if the fiber cables are run under the floor instead of in overhead trays, since fiber congestion under the floor can restrict air floor, reducing the ability to provide adequate cooling to the equipment racks.
Figure: Notes from a conversation with the former CTO of a large MTDC and photo of overhead cable management.
While the above discussion holds for a single MDTC building, the growth in demand for connectivity has driven the need for campuses with multiple interconnected buildings. This increases the challenge of fiber management since there will be significant fiber trunk lines between the buildings. Since MTDC operators work hard to attract large carriers and service providers to the initial build-out of the campus (since this will attract the customers), these large service providers are often concentrated in the first building on the campus. This concentration of carriers leads to a significant need for inter-campus connectivity to connect later customers to these large carriers, with new large count fiber cables needing to be pulled between building to handle changing connectivity demands. For these and other reasons, the dynamic nature of the connectivity requirements on a MTDC campus create fiber management challenges.
A solution for the challenges discussed above is the Telescent Network Topology Manager (NTM). As will be discussed below, while the function of the Telescent NTM is to remotely configure and reconfigure cross connects, one benefit is that once a customer is connected to the NTM the external physical fiber connection is static and all the reconnections are done within the NTM. This means that there will be no more overflowing fiber trays or the need to pull new fiber between buildings to deal with the changing fiber connectivity requirements.
The Telescent NTM offers complete cross connect lifecycle management. The system monitors, maps and controls the network during installation, reconfiguration and churn of cross connects to enable a Lights-Out Data Center with machine accurate inventory while preserving the value of the installed fiber plant. The NTM consists of 1,008 input and 1,008 output ports, each connected by a short, uninterrupted internal fiber connection. When a reconfiguration is requested, a robot-driven gripper removes an internal fiber from the original port and moves it to the desired new port. The patented algorithm identifies the unique path to route the fiber around the 1,007 other internal fibers in the system to establish a non-blocking, any-to-any connection. The Telescent NTM is strictly non-blocking and completely automated – essentially unlimited configuration and reconfiguration is possible with the Telescent system without any on-site, manual labor and with the original external fiber connections. The NTM can be configured in a leaf-spine network to allow scaling to >10,000 connections while still preserving the ability for any-to-any connectivity. Since the reconfigurations are controlled by software, all connections are recorded in a database and the state of any connection can be verified at any time providing machine accurate inventory for accurate billing to customers.
Unlike with the manual patch panel, once a customer is connected to the Telescent NTM the customer can be connected to any other enterprise connected and service provider to the NTM network. The Telescent NTM can be expanded in a pay-as-you-grow design, adding nodes in the leaf-spine architecture as needed as the campus MTDC grows. This allows the customer to be connected to any enterprise on the campus with the same initial fiber connection from the customer to the NTM. Since the reconfiguration is done internal to the Telescent NTM, none of the eternal fiber connections need to be replaced. No more overfilling of cable trays or constantly pulling new fiber between buildings to handle changing connectivity requirements.
And one more thing, while this article has talked about the benefits on the fiber infrastructure by using a robotic system for configuring cross connects, avoiding a manual approach has other benefits. As has been demonstrated by multiple surveys by the Uptime Institute, many problems are caused by human error. Anecdotally we have been told that 40% of the time when a technical works on a service ticket, he solves the initial problem but causes a new issue. So keeping technicians away from the fiber will also minimize other problems caused when working on the initial request.