SFF connector battle is far from over

With several small-form-factor connectors on the market, which designs are winning industry acceptance?

In 1997, when the TIA TR-41.8.1 working group evaluated five small-form-factor (SFF) connector designs as part of an initiative to update the technology specified in the TIA/EIA-568A Commercial Building Cabling Standard, the final vote indicated the lack of a majority consensus. The result was a decision to leave the older duplex SC connector technology in place as the standard at the wall outlet in 568B.3. The TIA also agreed to officially sanction the commercial use "behind the wall" for any connector that met the Fiber Optic Connector Intermateability Standard (FOCIS) and satisfied the performance requirements specified in Annex A of 568B.3.

Many in the industry characterize the TR-41.8.1 decisions made in late 1997 as an agreement to "let the market decide" which SFF connectors work best in commercial-cabling infrastructures. Two years later, four of those connectors have emerged as contenders in the premises market--Lucent Technologies' LC, 3M's VF-45, Panduit's Opti-Jack, and the MT-RJ, developed by a consortium comprising AMP, Siecor, Hewlett-Packard, US Conec, and Fujikura.

As the fiber interconnect in premises networks, and eventually, at the desktop, SFF connectors were designed to resemble the user-friendly, 8-pin modular RJ-45 copper connectors. About half the size of the older duplex SC and ST connectors, duplex SFF devices offer higher port density at lower cost and open the door to fiber for eventual parity with copper by promising many of the same advantages.

In 1998, SFF connectors accounted for only 1.9% of total North American connector, coupler, adapter, and cabling-assembly shipments, estimated at $1.2 billion by Fleck Research (Santa Ana, CA). Nevertheless, as part of the fastest-growing connector segment (duplex/multifiber), the technology and its implications have generated considerable excitement in the fiber-optic communications industry. In five years, SFF connectors will represent 17.7% of a total $1.3-billion North American market (not including prewired shelves).

"The demand is so great, that price is not an issue," says Ken Fleck, principal at Fleck Research. If AMP could ship $20 million of the MT-RJ this year, the customers would easily buy that much--they are going to be straining, I think, to ship much more than half of that amount."

Which SFF design will dominate the market? "The war is really going to focus on the LC, the MT-RJ, and the VF-45," says Fleck. "I think that one design will become the winner in the sense that it has half of the market, and the other two will share the balance." According to Fleck's five-year forecast, the LC, MT-RJ, VF-45, and Opti-Jack combined will account for $243 million in North American connector shipments in 2003.

Today, each of the four SFF designs is available and competing in the market--unlike in 1997 when the TIA evaluation took place.

Last to market of the four, the MT-RJ became available as a field-installable device in April. Now, all are available in duplex multimode or singlemode configurations and a few of the manufacturers offer prepolished models.

As the premises market slowly begins to emerge, the manufacturers behind each SFF design are quickly negotiating licenses with component suppliers and forming alliances with transceiver,

LAN electronics, and cabling-equipment vendors to ensure end-to-end solutions that incorporate and support their SFF interfaces.

Toward that end, the first SFF transceivers are reaching the market. Like the SFF connectors, the SFF transceivers are roughly half the size of their 1-in predecessors, conforming to a standard footprint outlined in the Narrow Width Form Factor package and pin definition, announced in February 1998 under a multisource agreement between AMP, HP, Lucent, Nortel, Siemens, and Sumitomo. While the agreement specifies 10-pin and 20-pin configurations, it does not dictate an optical receptacle/connector. The smaller transceiver size enables users to double port density by fitting twice as many transceivers onto a printed circuit board and to lower overall system cost. Some vendors will ship SFF transceivers that support 2.5 Gbits/sec over multimode fiber by the end of this year.

The systimax optispeed LC connector, marketed by Lucent's Microelectronics Group (Norcross, GA) and developed by Bell Labs, has been on the market since April 1997. Its FOCIS 10 document was approved last month. The connector uses a 1.25-mm ferrule and has a guaranteed 0.1-dB average insertion loss for both singlemode and multimode configurations.

"This performance is critical for the local area network," asserts John George, systimax fiber offer development manager at Lucent, "because applications such as Gigabit Ethernet and certainly the 10-Gigabit Ethernet that's now being developed by the IEEE require much lower insertion loss in the fiber-optic channel than slower-speed applications."

By September, Lucent had shipped more than 1.5 million simplex LC connectors "into the cabling systems infrastructure," resports George. Of the connectors shipped, approximately 60% were singlemode configurations about 40% were multimode.

Fleck Research analysts forecast that North American sales of both the singlemode and multimode LC connectors combined will reach $111 million by 2003. The analysts forecast wide adoption of the singlemode LC among Lucent's telecommunications customers for use in their backbone infrastructures. Its adoption in horizontal premises applications is still unclear, despite its swift market penetration, say analysts.

The MT-RJ connector, which led the TIA/EIA-568B wall-outlet standardization in 1997 and missed confirmation by only five votes, became available as part of cable assemblies late last fall. According to Fleck Research, MT-RJ North American sales were less than $6 million in 1998. Such sales are forecast to reach $71 million by 2003.

Based on AMP's Mini-MPO design and the MT ferrules developed by Nippon Telegraph & Telephone (NTT, Tokyo), MT-RJ singlemode and multimode connectors and cabling assemblies are manufactured by AMP and Siecor. The ferrules are supplied by US Conec and Fujikura. The connector has an RJ-45-like reverse latching mechanism and is easy to install and terminate, say the manufacturers. Its average insertion loss is 0.3 dB.

"One of the strengths of the connectors that have been introduced by Siecor and AMP, primarily, but also our other licensees, is the fact that it is a no polish, no epoxy connector allowing for quick and easy termination, reducing the training and the labor in the field," says Tony Beam, director of systems marketing at AMP (Harrisburg, PA).

Last to market of the four designs, the later release of the MT-RJ has not hampered the consortium's success at generating widespread support from network equipment manufacturers and licensees. Nor has its ongoing FOCIS 12 process-the MT-RJ as of press time was the only one of the four SFF designs without this proposal finalized.

The VF-45 duplex SFF connector, developed by 3M Telecom Systems Division (Austin, TX) eliminates the ferrule and instead uses V-groove technology to align the fiber cores. The absence of the ferrule, which is replaced by a few injection-molded plastic parts, makes the VF-45 the least expensive of the SFF connectors. The average insertion loss at 1310 nm is 0.20 dB for the singlemode VF-45 and 0.28 dB for the 50-micron multimode VF-45.

The VF-45 is the fiber-optic connector used in 3M's Volition Cabling System, the brand under which 3M sells both fiber and copper cabling solutions. In May, 3M introduced a duplex singlemode VF-45 configuration. The company declines to disclose total VF-45 shipment numbers, but Bob Jensen, technical services representative, says, "Millions of the connectors have been installed worldwide, all within the premises." Like the LC and the MT-RJ, Fleck Research expects the VF-45 to gain a foothold in the SFF market, with connectors and cabling assemblies combined reaching $56 million in North America in 2003.

The VF-45 has met with success in several standards organizations. It was the first SFF design to receive FOCIS documentation (FOCIS 7) last February. The connector was also adopted by the Fibre Channel Association in February 1997 as the standard SFF interface for future variants. (However, the Fibre Channel Association is reconsidering the MT-RJ and LC interfaces in current draft document work.)

Internationally, the VF-45 and the MT-RJ have both been approved as "work items" (IEC 86B) on the agenda of the International Electrotechnical Commission (IEC) in Geneva.

Panduit Corp.'s Fiber Jack SFF connector, available since the end of 1996, is marketed as the Opti-Jack. It features a ceramic ferrule in a split-sleeve design. Average insertion loss is 0.3 dB for both multimode and singlemode. According to Bob Mason, product development manager at Panduit (Tinley Park, IL), more than one million fibers had been terminated with the connector as of September. Fleck Research forecasts that North American Opti-Jack sales will reach $5 million in 2003.

Fiber Jack had its FOCIS 6 documentation published this March. The SFF connector is behind its competitors, however, in licensees and third-party equipment vendor support. "We've got a number of license agreements signed and more in the process, but I don't want to preannounce products for companies," says Mason. "We are working on the active side, but it has been a different emphasis for us because our strength and our focus has always been on the passive connectivity side, so that's where we started."

While the hard feelings generated by the connector standards have subsided, the standards issue won't go away. At a TIA TR-42.1 subcommittee meeting held in mid-August in Ottawa, Canada, balloting comments from MT-RJ manufacturers AMP and Siecor led to the formation of a task group to discuss criteria for evaluating connector proposals. Debbie Ryan at Fairplay was appointed as the independent moderator of the newly formed task force.

"AMP and Siecor had similar ballot comments to accept the MT-RJ as the connector type at the outlet," recalls AMP's Beam. "The chairman and the committee decided because of procedural issues, that the ballot comments could not be acted on as presented, and they had to bid on an official request to open up the connector issue for discussion again.

"AMP and Siecor did not request that there be a full-blown working group established to consider all the SFF connectors," asserts Beam.

Meanwhile, attendees at the Ottawa meeting had different opinions about where these developments might lead. Will manufacturers get another opportunity to convince the TIA subcommittee to standardize on their SFF design? "I believe that the connector issue will be reopened," says 3M's Jensen, who attended the Ottawa meeting. "What's really difficult is the number of people that voted on that-it's kind of awkward to have 25 people make a decision about what's happening with connector issues that will affect the entire world. "

Jensen, who is the chair of the tia tr-42.2 Residential Cabling standards committee, also found it interesting that the same people voted to accept all of the SFF connectors throughout the premises at the residential cabling meeting held in May.

"We don't think its necessary to reopen the issue," continues Jensen. "If it is going to be reopened, we think that all the SFF connectors should be accepted at the outlet as well as throughout the premises as long as they meet the 568B.3 document, because it really allows the end user to make a selection. Yet at the same time, it is meeting all the performance criteria and all of the interface criteria that's laid out within a standard."

Panduit's Mason, another participant in the Ottawa meeting, holds a similar view: "The point that we're going to try and support in the standards bodies is that end users need to have a choice of what is functional for them. The way that we try and control this so that it's not a free-for-all for end users is to say that an approved intermateability spec has to be in place for a connector to be a standard."

Lucent's George says, "We support opening up the telecommunications outlet at the desk to any of the SFF connectors that have been accepted for use throughout the rest of the building."

What happens next will depend on the decisions reached by the task force. The task force is likely to present that information in November when the TIA TR-42 committee is scheduled to reconvene in Reno.

Market analyst Ken Fleck says, "It's too late for the tia/eia to make an SFF selection, the SFF connectors are too entrenched in the market."

All of the SFF connector manufacturers agree that mass migration from copper to fiber cabling in the horizontal premises market is years away, although many are positioning their connectors as the interconnect for fiber-to-the-desk, among other applications. The initial market for SFF connectors and the supporting cabling and hardware in the premises arena is primarily in the backbone and campus-cabling infrastructures to accommodate more traffic as networks reach gigabit speeds.

Despite recent developments, the race to gain market share in the emerging SFF connector arena is still in the early stages. "Currently, there is no clear winner in the competition," says Fleck.