Key considerations in a long-term 40/100GbE cabling plan

Data centers are experiencing strong adoption of 10 Gigabit Ethernet (10GbE) switches for server access, and 40GbE and 100GbE for uplink, aggregation and core deployments, according to a recent Crehan Research forecast. In server-class adapter and LAN-on-motherboard, 10GbE unit shipments will eclipse those of 1GbE by 2016.

The convergence of bandwidth-hungry voice and video over IP-based networks, visual collaboration at the desktop, intra-office mobility, and the proliferation of real-time visual content streaming are driving the need for network upgrades.

But the transition to 40/100GbE will likely ramp up five years from now as the majority of applications now are still running on 1GbE and 10GbE architectures. That transition will most likely begin at the data center backbone before eventually migrating throughout enterprise structured cabling.

Copper to fiber

Although both fiber and twisted pair copper wires support 1000BASE-T and 10GBASE-T, the gradual migration to higher-speed connections and networks has seen more data centers choosing fiber-optic cabling over copper cabling for signal transmissions.

In contrast to copper, fiber optic cables are designed to support higher speeds; carry large capacity; transmit signals farther without needing to be ‘refreshed’ or strengthened; and offer greater resistance to electromagnetic noise.

However, a wide range of fiber grades are available so effective planning and implementation is important to fully realize the opportunities and benefits of 40/100GbE.

To achieve the higher bandwidths needed for 40Gb and 100Gb backbones, the ISO, IEC and TIA standards committees have defined the Optical Multimode 4 (OM4) standard for multimode 50-micron laser-optimized fiber cable, allowing OM4 to be specified by Ethernet and Fibre Channel applications.

The previous OM3 multimode standard operates on 2000 MHz*km Effective Modal Bandwidth (EMB). OM4 specifies increased bandwidths at 850 nm of 4700 MHz*km EMB for laser sources. This translates to longer transmission distances for the OM4 fiber than the OM3.

The IEEE 802.3 standard for 40GE and 100GE includes specifications for operation over OM3 and OM4. OM3 is specified to 100m and OM4 to 150m using parallel optic transmission. Advanced enhancements have enabled some solutions to extend these distances up to 140m and 175m respectively, avoiding the higher costs associated with single-mode fiber.

Fiber choices

In the 2013 CommScope Enterprise Survey, 55% of respondents expect to deploy a multimode, laser-optimized optical fiber in their data centers’ transition to 40GbE. Of these, 35% anticipate using OM4, while 20% prefer OM3. In the transition to 100GbE, however, OM4 multimode fiber will be the cable of choice.

In 10Gbps networks, laser-optimized 50μm multimode solutions are specified to 550 meters using 850 nm VCSEL short wave transceivers for transmitting and receiving across optical fiber. These solutions offer more than enough reach to connect an in-building backbone.

This extended reach creates opportunity for single-point administration topology as a low-cost design alternative and more campus backbones can be supported at 10Gbps over a lower-cost multimode alternative to single-mode.

Nonetheless, a solution for fiber technologies that meets and exceeds current standards provides a clear 10-40-100GbE as well as 8-16-32G Fibre Channel upgrade path.

At the same time, backward compatibility with legacy LAN applications is a major consideration for organizations running on Ethernet, Fast Ethernet, Gigabit Ethernet, FDDI, ATM, SONET, Fiber Channel and Token Ring.

High density, smaller space

As fiber technologies help data centers to keep pace with the increased amount of information flooding network space, an ultra-high-density fiber solution is needed to manage capacity, optimize spending, and improve accessibility for installation and maintenance.

Manage capacity: A system designed with more cabinet and shelf space to contain either multi-fiber push-on (MPO)-to-duplex Lucent Connector (LC) modules or MPO connector pass-through panels provide the high density needed in fiber-rich environments. The use of modules and panels allows incremental expansion.

Optimize spending: Choosing the right network infrastructure physical layer solutions at the outset can help data center managers keep cabling infrastructure costs to less than 5% of the total cost of IT operations over a 15-year period.

The solutions have to be more efficient with rack space; prolong the need for data center expansion without sacrificing performance; offer added space for increased airflow to reduce heat; and safeguard IT investments from network and technological advancements.

Improve accessibility: A well-designed system should enable installers to perform fast installations, moves, adds and changes with minimal downtime. Data center operators should also have the flexibility to increase capacity as demand grows.

Pre-terminated, factory-tested trunk cables, array cords, ruggedized cables and patch cords simplify connections and reduce installation time. Modular panels offer convenient cable management and rear access, while minimizing restrictions to air flow.

Essentially, the idea is to deliver high-performance connectivity in a smaller space.

Fiber care

While fiber-optic cabling delivers far greater bandwidth than traditional copper cabling, any damage to even a single fiber can cause a highly disruptive and costly outage.

To safeguard, route and manage fiber-optic cabling, a cable management solution secures and protects delicate fiber-optic cabling for cable protection and ease of installation.

The solution should:

  • Protect, isolate and identify all fiber-optic cables end to end
  • Prevent micro-bending and potential crushing due to uneven support
  • Provide a dedicated routing path for enhanced management
  • Ensure a minimum bend radius of 30mm to protect bend-sensitive fiber

Ultimately, a well planned and implemented fiber cabling strategy will ensure dependable migration paths that help the data center keep pace with the growing communication requirements of 10/40/100Gb signal transmissions.

When planning for fiber in the data center or LAN, consider the solution’s performance, reliability, cost, flexibility of deployment, and ease of accessibility. The cabling infrastructure underpins the mission-critical operations of highly connected and dynamic businesses. So, it is imperative for organizations to pick the infrastructure that best fits their unique business requirements.

This is a QuestexAsia feature commissioned by CommScope.