RJ-45: A Mainstay in the Data Center
July 20, 2017 / Mark Dearing / General
Twisted-pair copper cabling is a cornerstone of data center infrastructure, and the RJ-45 connection is the highest-volume port type in servers today, with close to a billion ports of RJ-45 connectors sold every year. The features in RJ-45 that made it appealing in the past are still true today, as new Cat 8 systems for 25 and 40 Gbps networks will continue to use the popular connector design. It is for this reason that Fluke dedicated significant time and resources to ensure utmost accuracy between Cat 8 RJ-45 connections and its new DSX-8000 CableAnalyzer.
The Cat 8 specification from TIA defines channels and connecting hardware up to 2000 MHz and 30 meters, using the standard 8P8C/RJ-45 interface. This interface allows the cabling system to be backwards compatible with existing category cabling systems. For data center managers, backwards compatibility and auto-negotiation between active equipment provides huge benefits.
Backwards Compatibility Makes Migration Easier
Data center managers who are planning for upgrades in the near future should consider the expected life of the cabling system to maximize their return on infrastructure investment. Cat 8 cabling with RJ-45 connections can support 10 Gbps today, while providing a seamless migration for 25 or 40 Gbps tech refreshes in the future. This prevents the need to re-cable during upgrades, avoiding possible network disruption and additional costs.
Auto-Negotiation for Mixed Server Speeds
Data center managers can also leverage the auto-negotiation requirements in the 25/40GBASE-T standard. Auto-negotiation allows for two Ethernet devices to connect to each other and select a common transmission speed that both devices support. For example, 25 Gbps switches can communicate with 10 Gbps servers, whether over Cat 8 or Cat 6A connectivity. This also allows for network migration to 40GBASE-T to be done in phases, allowing for more flexibility in terms of timing, disruption, and cost. With staggered active gear upgrades, BASE-T solutions can allow for mixed server speeds in each rack or cabinet supporting any combination of 1, 2.5, 5, or 10 Gbps servers, creating better port utilization of the switches.
RJ-45 is here to stay
There is no one-size-fits-all solution for cabling infrastructure in a data center. It breaks down to what best fits the layout, scope, bandwidth needs, scalability, manageability, and budget of a specific facility. But as emerging data center architectures create a need for more flexibility and scalability using high-speed copper links, the demand for faster gigabit performance in a smaller footprint will continue to grow. With BASE-T providing the most cost-effective access layer networking option, copper structured cabling solutions will continue to be fundamental throughout the data center infrastructure.
Mark is a Senior Product Manager for Leviton Network Solutions, and has been with Leviton since 2006. He manages a diverse portfolio of products including shielded systems (Category 8 through 5e), modular patch panels, cable management products, power solutions, and software-managed intelligent solutions. He is certified as a BICSI Registered Communication Distribution Designer (RCDD), is a Certified Data Center Designer (CDCD), and is an active participant in standards development with the Telecommunications Industry Association (TIA). Mark is also a co-inventor of several patented products and design features.