TIA Subcommittee approves ANSI/TIA-942-A-1, addendum to data center cabling standard

At this week’s meeting of the Telecommunications Industry Association’s (TIA) Engineering Committee TR-42 Telecommunications Cabling Systems, Subcommittee TR-42.1 Commercial Building Telecommunications Cabling agreed to recommend the approval for publication of the first addendum to standard ANSI/TIA-942-A Telecommunications Infrastructure Standard for Data Centers.

The formality of the approval process includes TR-42 accepting the recommendation from TR-42.1 and approving the addendum for publication. A two-week editorial review is followed by a publication authorization. Sometime after the authorization is issued, formal TIA and ANSI procedural steps are completed and the document is available for publication. Those procedural steps frequently take a couple months.

As we previously reported, the first addendum to ANSI/TIA-942-A addresses guidelines for what are known as data center fabrics. The need for such fabrics, and some standardized specifications for them, has emerged in large part because of the proliferation of cloud computing environments as they exist in data centers as well as the inherent connection between cloud computing and virtualization. The addendum applies the cabling architectures established in ANSI/TIA-942-A to data center fabrics.

While we are not certain of the completed addendum’s exact wording, an early draft addressed data center architectures and traffic flow as follows: “The traditional architecture is well-suited for traffic between servers on the same access switch and from servers to external destinations. However, it isn’t suitable for large virtualized data centers where compute and storage servers may be located anywhere in the data center.” The document then provided examples of alternative switch architectures—or fabrics—that have been put forth within the networking industry. These architectures include models known as “fat tree,” “full mesh” and “centralized switch.” More significantly, the draft addendum addressed the means by which these fabrics can be cabled.