Testing Times for Network Engineers
However, fixed wire technologies continue to play a major role. Immediate access to bandwidth hungry media relies on having a strong robust Backhaul network and 10GigE is becoming more widely used in Access networks.
The Cisco VNI Global Forecast predicts that IP traffic will reach 110 Exabytes (110 billion gigabytes) by 2016, an increase of 250% over 2012. However, as Network Traffic has continued to grow in recent years, Global Carrier revenues have decreased. The market demands access to content at low prices, and Operators must develop efficient networks that meet market expectations profitably.
Cost per bit is widely used as a measure of network efficiency and is becoming one of the most important targets to meet. The Backhaul network is expected to maintain a high quality of service, but deliver more for less in a bid to maximise profit.
Increasing the number of wavelengths used on a single optical fibre, i.e. increasing the number of channels of a DWDM system from 40 at 50GHz channel spacing to Ultra-Dense WDM having 80 channels at 25GHz spacing, and / or using modulation schemes such as DQPSK (Differential Quadrature Phase Shift Keying) to upgrade 10Gbps data links with 40Gbps, or DP-QPSK (Dual Polarisation – Quadrature Phase Shift Keying) to 100Gbit/s and recently 64QAM (Quadrature Amplitude Modulation) to reach transmission speeds up to 400Gbps per wavelength in the search for more bandwidth.
World leading Universities and R&D organisations are using the Anritsu MP1800A Signal Quality Analyser to support development of future technologies, such as 400Gbps advanced modulation.
In the future SDN (Software Defined Networks), currently being defined by the Standards bodies and developed by systems vendors, enabled mainly by managed Ethernet and OTN technologies, will provide the flexibility needed to allocate bandwidth to meet a client’s demand, but release it to be used elsewhere when it’s not required. Operators will benefit from more efficient use of their network while the client only pays for the bandwidth they use.
As a result, the trend is for exponential growth in Ethernet and OTN, but networks must continue to support legacy technologies, such as PDH; SDH; SONET; Fibre Channel, etc., simultaneously. Testing the network will become more complex and demanding. Engineers are expected to be proficient in all technologies and they can be expected to work with any and all technologies as needed.
Newer ITU standards released between 2009 and 2012 has seen OTN moving from Submarine and Core networks to Metro and even Access networks. The core areas of these newer releases included areas such as ODU0, ODUflex and Multistage Mapping. With these newer technical abilities and OTN moving into this much larger market segment, it’s very important that operators not only test at the OTN level but also the client traffic over the different OTN layers.
40G / 100G Ethernet and OTN (OTU3/4) is now a requirement for many operators as demand for network capacity continues to grow. OTN is essential for Operators to ensure efficient network resource management, easy and flexible transport of any access signal and enhanced QoS in their client SLAs.
The size and cost of the optical transceivers for 40G and 100G (CFPs), have been a major limiting factor for network and test equipment vendors, the cost per port has often been prohibitive. A second generation CFP2 has a smaller form factor (about half the size) and requiring much less power to operate. They can be produced for a fraction of the price and can revolutionise the design of network and test equipment alike.
Although CFP2 is now available from several manufactures we are yet to see them in mass rollout in switching equipment. The CFP2 will eventually be superseded by an even smaller and more efficient CFP4, at which time it will be possible to design 100G test capability into smaller test instruments.
Anritsu’s new evolution of ruggedized field test platform, the Network Master Pro is hardware complete and designed to support legacy and keep abreast of emerging technologies and tests all layers of client OTN mapping. The ability to inject client traffic over the Ethernet or SDH/SONET layer and monitor or receive it in another part of the OTN over an OTN layer, will become critical. It is the only way for the operator to truly understand what is happening in their network, or divide their network to assist in fault finding and throughput testing for their client. With key metrics and alarms at every level, The Network Master Pro assists engineers to identify any errors and provide fast fault analysis to the route cause.
About the author: Andy Cole is UK Business Development Manager & Applications Engineer at Anritsu EMEA Ltd.