Network Infrastructure Blog

Siemon expands its comprehensive line of fiber trunking solutions with XGLO RazorCore assemblies. Siemon’s RazorCore cables have a significantly reduced cable outside diameter (OD) for maximum space savings and air flow.

Siemon Razorcore fiber cable

Available in OM3 and OM4 laser-optimized multimode fiber and in singlemode fiber, XGLO RazorCore Assemblies provide an efficient, cost-effective alternative to individual field-terminated components. By combining the performance of factory termination with the reduced OD of Siemon’s RazorCore fiber, these new assemblies ensure both superior reliability and space utilization in data centers, Storage Area Networks (SANs) and Local Area Networks (LANs), while offering up to 75% faster deployment over traditional field termination. Compatible with all Siemon fiber enclosures, the new XGLO RazorCore assemblies feature an optional encapsulated protection sleeve with cable pulling eye to fully protect the fibers during installation.

“When selecting a fiber optic solution for our data centers, we wanted a solution that was fully scalable and allowed for the maximum density possible,” says customer Jean François Tremblay, Data Center Manager at Orange Business Services (a subsidiary of France Telecom), who recently installed XGLO RazorCore fiber trunking assemblies. “With Siemon’s reduced diameter RazorCore we were confident that the product could accommodate future growth both in space, due to the reductions in tray and pathway fill, and bandwidth, with the straight-forward upgrade path.”

“Siemon precision cable assemblies are 100% inspected for superior performance and enhance the installation method popular in today’s data centers. By expanding our offering with smaller-diameter RazorCore assemblies, our customers also obtain an average 50% size reduction compared to traditional assemblies,” says Kevin Stronkowsky, Fiber Optic Product Manager at Siemon. “This results in less cable tray fill, reduced pathway restrictions and better airflow—all of which support higher densities with improved efficiency and reduced cost.”

Warranted for 20 years, XGLO RazorCore Fiber Assemblies come with 900um simplex breakout, 2.0mm duplex breakout, simplex and duplex SC or LC connector types, as well as SC-LC hybrid options. The RoHS-compliant assemblies are available in a variety of jacket ratings, including Riser, Plenum and Low-Smoke, Zero Halogen. Available with 12, 24, 36 or 48 fiber counts, custom assemblies are easily created with Siemon’s flexible part number scheme to meet specific customer specifications and performance needs. Each XGLO RazorCore Assembly is designated for proper connector orientation, coded with a unique identification number and individually packaged with a dual shelf reel to protect connectivity during payout.

Learn more about XGLO RazorCore Fiber Trunking Assemblies.

More than century after eight-year old Virginia learned from the editor of the New York Sun that there was indeed a Santa Clause, IT managers and end users who recently learned about TIA’s latest “category 8” can rest assured that there is indeed an existing standards-based category 7_A.

Yes, that’s right. After much debate, the Telecommunications Industry Association (TIA) TR-42.7 Copper Cabling Subcommittee recently adopted “category 8” as the nomenclature of their next generation balanced twisted-pair cabling system to eventually support 40 gigabits per second (Gb/s) in a two-connector model at some distance shorter than 100 meters (m). TIA moving consecutively from category 6A to category 8 has caused some confusion in the industry, and some are asking, “Is there a category 7?”

As was so eloquently put to little Virginia regarding the existence of Santa Clause when the editor responded, “Your little friends are wrong. They have been affected by the skepticism of a skeptical age,” the same holds true for category 7_A. Despite what the skeptics say, this standards-based cabling system is here now and here to stay. Furthermore, it offers the benefit of interference-free cable sharing.

A Standards-Based Existence

Ratified in 2002 by the International Organization for Standardization (ISO) under ISO/IEC, 11801, 2nd edition, category 7 (class F) cabling, is a fully-shielded cable characterized up to a bandwidth of 600 megahertz (MHz). In 2010, Amendment 2 of ISO 11801 specified performance for category 7_A (class F_A) cabling. Also a fully-shielded S/FTP cable, category 7_A offers an extended frequency bandwidth of up to 1000 MHz. Siemon’s TERA 1000 MHz cabling exceeds all ISO/IEC requirements for category 7_A/class F_A transmission performance.

Due to its fully shielded design, TERA 1000 MHz category 7_A cable provides higher performance than unshielded twisted-pair (UTP) cabling. At higher frequencies, the use of individually shielded pairs virtually eliminates internal crosstalk between pairs and external cable-to-cable alien crosstalk, both along the cable run and at the connector. In fact, at 1000 MHz, TIA’s proposed performance limits for category 8 do not currently meet those specified for Siemon’s TERA category 7_A cabling. Furthermore, the cable’s outer overall braid shield provides additional strength and a low impedance path to ground that provides superior resistance to electromagnetic interference and radio frequency interference (EMI/RFI).

ISO/IEC specifies two connector options for category 7 and 7_A—an RJ-style connector as defined by IEC 60603-7-7 and a non RJ-style connector as defined by IEC 61073-3-104. The non RJ-style connector is based on Siemon’s TERA connector, which when installed as part of a complete TERA solution, delivers up to 1.2 GHz of bandwidth to exceed the bandwidth of category 7A/class FA specifications.

Unlike the RJ-style interface, the TERA connector offers a unique isolated quadrant design interface that that allows easy access to one or two pairs of a channel to better accommodate cable sharing—the practice of running more than one application over different pairs of a twisted-pair copper cable. Some skeptical designers and consultants are still concerned about specifying cable sharing because they are unsure of the Standards’ acceptance of the practice. The good news is that both TIA and ISO recognize and provide guidance on cable sharing implementation. In fact, ISO/IEC 15018 specifically recommends that cable sharing be considered when pathway space is limited and identifies the IEC 61073-3-104 TERA connector as the preferred interface for this application_.

Doing Its Fair Share

Fully-shielded cabling systems like Siemon’s TERA category 7_A system are much better at cable sharing than unshielded twisted-pair (UTP) cabling. That’s because the internal crosstalk coupling (both near-end and far-end) in UTP cabling systems makes it difficult for users to predict whether multiple applications can coexist in one cable. In fact, standards caution that when deciding which applications can share a UTP cable, users should be aware that crosstalk from applications operating in similar frequency bands can potentially interfere with one another. On the other hand, a TERA system guarantees that there is sufficient noise isolation between pairs to support multiple applications, or the multiple appearance of any one application, over a four-pair channel.

How specifically does cable sharing work? As with any category 7_A cabling channel, all four shielded pairs are terminated to a single TERA outlet. However, in addition to accepting a 4-pair cord, the TERA connector can also support four 1-pair cords, two 2-pair cords, or a combination of the two—without the need for splitters or adapters. A single TERA outlet can therefore support multiple 1- and 2-pair low-speed applications or one 4-pair high-speed data application like 1000 Mb/s (1000BASE-T) or 10 Gb/s Ethernet (10GBASE-T). Cable sharing implementation practices are extremely flexible and support a wide range of configurations. The table below shows some typical 1- and 2-pair applications that can easily be supported with this cable sharing method.

By allowing various applications to be converged onto a single cable, the unused pairs that would be present if a 4-pair channel was dedicated to an application transmitting over just one, two, or three pairs are eliminated. TERA’s cable sharing capabilities therefore significantly reduces the number of cables required, subsequently reducing pathway costs and cable management complexity. For example, in a call center a single TERA connector can support four 1-pair analog phones for a cost savings in excess of 10 percent for materials and a 39 percent reduction in the total number of outlets.

Here Now and Here to Stay

While category 8 may now be on the TIA table, Siemon’s TERA category 7_A is an existing standards-based system that provides the benefits of cable sharing, higher bandwidth capacity and EMI/RFI immunity. And ISO/IEC is already looking toward the future with this technology. The nearly finalized IEC 61076-3-104, 3rd edition, will extend the performance of the IEC 61073-3-104 Siemon TERA category 7_A connector out to 2 GHz—the same frequency tentatively proposed for category 8.

Until the processing capabilities of a 40 Gb/s Ethernet application are finalized and more advanced and representative real-life analysis can be conducted, it is too early to guarantee 40 Gb/s support for any copper media. However, it does look as if Siemon’s fully-shielded category 7_A TERA system with its unique connector design will ultimately provide some support for next generation speeds of 40 Gb/s while offering the innovative capability of cable sharing.

So yes, IT manager, there is a Category 7_A.

Posted on the public area of the newly formed IEEE 802.3 Next Generation BASE-T study group is an interesting contribution by Dan Dove of Applied Micro Circuits Corporation proposing three distinct cabling reach topologies for different applications in the data center.  What’s notable about this presentation is that a global leader in the Ethernet chip development industry is clearly expressing an opinion on the controversial topic of shielded versus UTP cabling.

In his contribution, Mr. Dove proposes using shielded cables for support of Top-of-Rack (server to switch) applications because the media’s reduced echo and near-end crosstalk loss, reduced transmit power requirements, and virtually zero alien crosstalk support signal transmission with a simplified electromagnetic immunity (EMI) chip design.  Mr. Dove also questions the use of UTP cables to support the structured cabling End-of-Row topology (server to switch, switch to switch, and switch to core switch) connections because transmission over UTP media requires a more complex EMI chip design, introduces challenges related to additional return loss and near-end crosstalk loss, needs higher transmit power, and requires attention to the disruptive effects of alien crosstalk.

Points associated with shielded cabling:

• Simplifies EMI design
• Reduces Echo/NEXT challenges of multiple connectors
• Reduces TX power requirement
• Virtually eliminates ANEXT

Points associated with UTP:

• More complex EMI design
• Requires Echo/NEXT challenges of multiple connectors
• Increases TX power requirement
• Requires attention to ANEXT

Is this finally the tipping point for shielded cabling?

You can find Mr. Dove’s contribution here on IEEE802.org to explore this issue further.

In a converged cabling system, balanced twisted-pair copper cabling is used to interface between BAS software and IP-enabled BAS devices with modular RJ-45 interfaces or controllers that communicate with multiple BAS devices.

Figure 1 depicts structured LAN cabling connections, represented by blue lines, from a BAS server to an IP-enabled camera and a controller in a basic converged cabling example.

Figure1: LAN Cabling Connections

The cabling from the controller to the BAS devices, represented by green lines, is typically application dependent low voltage wiring (e.g. two 18 AWG conductors).  In some cases, non‑IP BAS devices can accommodate both LAN cabling and low voltage cabling connections.

When the option is available, the use of LAN cabling for non-IP BAS device connections is always recommended to facilitate future migration to a fully IP‑based building automation system.

Note that a Standards-compliant structured cabling topology includes one or two patch panels in the telecommunications room, an equipment outlet in the work area, and an optional horizontal connection point located in a zone box to facilitate BAS device adds, moves, and changes.  For simplicity, these connection points are not shown in Figure 1.

Learn about ConvergeIT, a converged, IP-based intelligent building cabling system using a single, simplified structured cabling infrastructure for a smarter, greener building.

The purpose of this document is to communicate Siemon’s position in response to a recent paper from a competitor titled, “Suitability of Category 7A/Class FA As A “Future Proofing Media For 40 Gbps Applications,” dated April 2012.  This document also conveys Siemon’s interpretation of standards activities relating to suitability of class F_A cabling (comprised of category 7_A components) for future networking applications having transmission rates above 10Gbps.

The TIA TR-42.7 Baseline Objectives for Next Generation Cabling identify the characteristic, “must exceed the TIA category 6A specification in at least 1 parameter” as “nice to have”.  Furthermore, the IEC/PAS 61076-3-104 Standard, which describes the performance of the Siemon TERA™ interface, is being updated to support frequencies up to 2 GHz.  Because class F_A exceeds all category 6A specifications for every transmission parameter, class F_A cabling is better positioned to support extended lengths, reduced latency, and reduced power consumption than any other copper media type, when a 40Gbps application is finally approved.  In the absence of application objectives or an IEEE 802.3 40Gbps call-for-interest (CFI), no one, including Siemon, can make definitive claims about the ability of specific twisted-pair cabling implementations to reliably support transmission rates up to or beyond 40Gbps at this time. Our position on the inaccurate statements included in the competitor paper regarding class F_A cabling is provided below:

In summary:

• Siemon’s class F_A compliant TERA™ solution is the highest performing copper system on the market (globally) and, as such, is better positioned to support future and emerging applications than any other copper balanced twisted-pair media type.
• Screened and fully-shielded systems offer power-saving advantages to PHY developers.
• Hybrid cords are approved and commonly used in both copper and optical fiber cabling systems.  The RJ-45 plugs at the channel ends are used for equipment connections and are not part of the TIA and ISO/IEC channel models.
• Siemon participates heavily in standards development and is conservative in our statements and performance claims.