The Telecommunications Industry Association's (TIA's) TR-42.1 committee is bringing small-form-factor (SFF) connectors out of the closet. The committee voted in early November to accept the recommendation of a task force that end users and network designers be allowed to specify SFF connectors at the wall outlet as well as in telecommunications closets under the upcoming tia/eia 568-B Commercial and Industrial Building Cabling Systems standard.
The new standard, expected to receive approval in the second half of this year, will be divided into three parts. The 568-B.1 document will provide general standards for such parameters as installation requirements, network topology, and test criteria with reference to its sister standards, 568-B.2 for copper components and 568-B.3 for fiber-optic components. The latter will include the new ruling on SFF use. While 568-B.3 will not remove the SC connector from consideration for outlet use, it will enable network managers to use SFF connectors all the way from the desktop to inside the closet.
To meet the specifications of 568-B.3, the SFF connectors must have supporting Fiber Optic Connector Intermateability Standards (FOCIS) documentation and meet the performance criteria set out in the standard. To aid in the use of SFF connectors, the task force offered a definition of such a connector: a duplex device with a footprint that approximates that of the 8-pin modular jacks typically used with 4-pair copper cabling.
This action represents the second time the committee--recently elevated from subcommittee status under TR-4--has addressed the SFF connectors in the context of the 568-B standard deliberations. Two years ago, the committee attempted to name a single SFF connector as standard for premises applications. The resulting debate turned into open warfare among the vendors of the five connectors offered for the committee's review. As a result, none of the connectors was approved for the outlet role, although the committee did allow the SFF devices to be applied to closet applications, providing they had their FOCIS documentation in order and met performance specifications.
Re-examining the outlet issue could have brought the simmering conflict among the vendors to a boil once again. "Needless to say, on the phone lines we had quite a few arguments over it, trying to determine the best way to do it," recalls Bob Jensen, a member of the task group who works technical services and standards issues for 3M (Minneapolis, MN). The task group finally decided that the solution already provided for the closet would probably work best for the outlet. Thus, the market will be left to decide which connectors will flourish in future premises applications.
"What it ends up as is that all of the small-form-factor connectors that have a FOCIS document behind them and that meet the performance criteria could be selected by the end user or designer for a project," says Jensen. So it seems assured that any battles for supremacy among the vendor community will take place in the marketplace, rather than within the standards bodies. "Effectively, what we've done is, instead of opening up this connector war thing again, it really closes any kind of war from going on. It's kind of like a war was called and nobody showed up," he says.
The TIA's decision to reopen consideration of SFF devices at the outlet arose from the work of other standards committees in the areas of residential cabling, where the connector choice was left open. "We've found that there has been no clear consensus going on with any of the applications standards that are out there," Jensen adds. In addition, there didn't appear to be any consensus in the market, except that SFF connectors from different vendors were finding use in a wide variety of applications. Users subsequently had begun to complain that forcing them to use different connectors at the outlet if they wanted to use SFF devices in the closet meant that they had to buy two sets of tools to accommodate the different connector types.
The new standard, which Jensen expects will be published at the end of the year, greatly simplifies network complexity for users and designers. The choice of connectors will be an important consideration, given the amount of connectors that networks conforming to 568-B.3 will require.