Introduction
Telecommunication service providers worldwide are constantly strengthening their networking infrastructure in order to improve their competitiveness and keep up with the increasing bandwidth requirements.
Increasing power consumption is one of the outcomes of these strong networks and the numbers behind this topic are becoming significant and can't be ignored. Current power consumption of the global networks is about 2% of global electricity consumption and while energy efficiency of networking gear is improving in absolute numbers, the power consumption of data networks continues to rise.
In addition to business case rational, there are several other reasons for paying attention for power consumption, including regulatory requirements, standardization requirements (such as IEEE 802.3az energy-efficiency Ethernet), procurement policies, and last but not least, "being green" is not only politically correct, but a real mindset for decision makers.
So "green requirements" contribute both for the bottom line and the environment and as a result networking elements with low power consumption are becoming important selection criteria and considered as valuable assets.

Measuring CAPEX is relatively easy, measuring OPEX is challenging
It is popular to break down the company's expenditures to capital expenditures (CAPEX) and operational expenditures (OPEX).
For telecommunication service providers, measuring and controlling the networking CAPEX is relatively easy - CAPEX is considered as the network elements cost and comparing products and capacities can be done easily.
Measuring and managing OPEX is more challenging, both financially and technically. Some OPEX items are not directly associated with the network operation and include selling, general and administrative (SG&A) expenses and space rental fees. OPEX items that are directly associated with the network operation include service planning and provisioning, service adjustments (add/remove/modify bandwidth settings) and service monitoring.

Power consumption as significant and manageable OPEX item
While measuring and managing OPEX is not trivial, power consumption optimization is both important and practical.
Lower power consumption is important since it captures up to quarter from the overall network OPEX and since long term perspective on electricity prices shows that they are clearly increasing.
Lower power consumption is practical and manageable since calculations are simple - they are numerical, constant, and breakable to products level. In addition, there is no management or political tradeoffs - lower power consumption simply lowers OPEX.

Source: powerpulse.net

Evaluating the impact of minimized power consumption in real-life Packet Transport Network switches
Networking infrastructure products requirements grow faster than silicon and cooling technologies, and popular design for complete products portfolio is based on reusing the high-end products to a medium/small products. As a result, a non-efficient solution in terms of power consumption is building entire networks. High-end methodology is also "reused" and therefore typical network operation is not designed to save power: all ports are rarely used, and for protection purposes, many linecards are in a standby mode.
Designing a power-effective Packet Transport Network switches requires both hardware and software considerations. Hardware-base considerations include selection of CPUs and memories, structure of forwarding engine, switch fabric and queuing, and even the power supply quality. Software-base considerations include the scalability and flexibility of the architecture that enables efficient modification for interfaces and features, and power saving algorithms for disabling non-used components.
Orckit-Corrigent designed and developed such technologies and the result is an innovative power consumption solution that is implemented on its Packet Transport Network (PTN) switches. The CM-4000 CE+T products are based on standard and interoperable Layer 2 MPLS and MPLS-TP technologies and include the ability to deliver low and high rate TDM services over packet-based networks. These capabilities enable phased migration for legacy metro networks and the delivery of enterprise VPN, residential triple-play and mobile backhauling services.
Comparable switches and routers with similar performance consume a larger amount of power and significantly increasing OPEX. This is being described in the following tables: 

• Table #1: power consumption analysis for small-size networking infrastructure equipment

• Table #2: power consumption analysis for medium-size networking infrastructure equipment

• Table #3: low power consumption impact on a basic network that is based on 20 small-size and 5 medium-size network elements

This numerical analysis is demonstrating how the Orckit-Corrigent low power consumption solution is significantly improving the ROI and reducing OPEX. Larger networks or longer time frame will only improve these savings.

Summary
Power consumption is a significant and manageable OPEX item that can't be ignored due to increasing awareness for electricity prices, regulation and standardization requirements and environmental concerns.

"Green Ethernet" improves both the network business case and the environment. There is a lot of room for improvement in today's networking infrastructure and designing hardware and software for significantly lower power consumption can be demonstrated.

Orckit-Corrigent is introducing the most effective Packet Transport Network switches in terms of power consumption and therefore the company's CM-4000 portfolio is offering a green solution with attractive ROI and significant OPEX saving. A comparison with similar network elements results with saving of thousands of USD that is even enhanced with bigger scale or longer time frame.