Thanks to ubiquitous corporate Ethernet and WiFi, we can happily share files with other users in the office, and make use of network resources almost as if they are running locally. Server-based applications can be accessed without a noticeable difference in performance compared to desktop-based applications. But resources outside the local area network have traditionally been a different story. Even if these were still resources located elsewhere on the corporate intranet, the wide area network (WAN) connection would most likely have been the weak link that made the resources far less pleasant to use. Whilst the WAN connection has been upgraded to Ethernet-grade performance too over the years, which has improved the experience considerably, that still leaves resources that sit outside the WAN in the same boat. Fortunately, Ethernet has the potential to grow into this area as well, with similarly positive results. In this feature, we explore the possibilities.
From traditional WAN to Wide Area Ethernet
Before the advent of the Ethernet WAN, slower technologies were used for the connections between LANs. These would typically be MPLS, T1/E1, ATM, Frame Relay, DSL and X.25. Not only are these technologies slower than Gigabit Ethernet in terms of bandwidth - typically offering only up to 150Mbits/sec shared between all users - expensive Layer 3 switching gear will also be required to convert the Layer 2 Ethernet of a corporate LAN to the Layer 3 WAN carrier protocol, and then back again to the Layer 2 Ethernet LAN at the other end. This switching introduces its own delays to the equation, which can affect the usability of latency-sensitive applications like remote desktops. The extra Layer 3 devices increase the chances of reliability issues as well, due to the complexity involved with the protocol switching.
Turning to Ethernet for WAN connectivity instead has alleviated these issues. Over fibre, Ethernet has a range of up to 40km, and bandwidth can be anywhere from 1Gbit/sec to even 100Gbits/sec. On top of the relative bandwidth benefits of an Ethernet WAN, it also only requires Layer 2 switching gear, which will be variants on the same equipment already in use for the LAN. The ubiquity of Ethernet in the enterprise, and its use for over 30 years, mean that the components involved will generally be a lot cheaper than other WAN connectivity options. Network administrators will already be familiar with setting up and managing WAN Ethernet protocols, too, as this will be essentially the same as the Ethernet used on the LAN.
On top of this, management and implementation will be simpler. Virtual Private LAN Services (VPLS) allow all the WAN technologies in use to be brought together into one logical Ethernet LAN. Pseudo-wire emulation means that legacy packet-switching networks can be operated as Ethernet, enabling Quality of Service (QoS) profiles to be set up so that bandwidth-sensitive applications like video and audio get the throughput they require. Keeping data within Layer 2 also allows multicast video streaming without the need for a specialist redesign of the network. So an Ethernet WAN pays dividends on a number of different levels compared to the technologies traditionally in use, ranging from bandwidth and price to ease of management and configuration.
To the WAN and beyond
But an equally large benefit can be obtained from deploying Ethernet beyond the WAN. When Carrier Ethernet 2.0 was launched by the Metro Ethernet Forum in early 2012, it expanded the possibilities enormously. The first set of standards bundled into Carrier Ethernet 1.0 were primarily focused on a single provider's network, specifying E-Line point-to-point connections and E-LAN multipoint-to-multipoint connections. These have eased the implementation of the Ethernet WAN for a single company, as E-LAN can connect multiple locations and even carry multiple, separate networks over the same cabling infrastructure. But Carrier Ethernet 1.0 didn't turn Ethernet into a commodity service that could be extended beyond a single vendor. In contrast, the second version of the standard means that the benefits of Ethernet don't need to stop where the WAN does.
The importance of E-Access
One of the most significant new features defined by Carrier Ethernet 2.0 that raises it beyond WAN usage is E-Access. This turns Ethernet into a service that can be provided as a commodity. The MEF 33 standard, part of Carrier Ethernet 2.0, defines how each customer's data can be tunneled securely across the service provider's network. However, it's the Multiple Class of Service (Multi-CoS) capability of Carrier Ethernet 2.0 that allows the service provider to preserve different bandwidth profiles and service level agreements alongside each other for different customers, whilst their data shares the same cabling infrastructure. These priorities remain intact as the data is transferred between LANs. They will also be preserved across service providers. This is a key feature, because it means that a company won't need to have the same service provider at all its locations, expanding the geographic reach of Ethernet-based networking still further.
One of the driving forces behind the need to deploy Ethernet beyond the LAN and WAN is the growth in adoption of cloud-based services. This has made the requirement for guaranteed SLAs even more intense, as well as the necessity of operations, administration and maintenance (OAM) tools to ensure the performance of business applications. These can operate at the service layer, link layer and at the local Ethernet virtual interface level. So service providers can drill down from the wider service right to the individual customer's service instance in search of a problem. Carrier Ethernet 2.0 specifically offers support for this. As a result. more dependable cloud services can be provided, because faults and performance issues can be detected and solutions worked out or failures routed around, in order to maintain the service level agreement. The OAM tools will also mean the dynamic provision of new services can be more easily monitored. The cloud services are often being delivered between service providers and their end users directly using Ethernet, without the Internet in between, with Amazon Web Services and Microsoft Azure both being delivered in this way by customer demand.
Mobile backhaul and bandwidth flexibility
Another key area beyond the WAN is in mobile backhaul, which again has gained considerably improved support in the Carrier Ethernet 2.0 specification. Ethernet has been used for mobile backhaul since Carrier Ethernet 1.0, making it a primary underlying technology for the mobile data revolution that has become so important in the last few years. The Multi-CoS capability in Carrier Ethernet 2.0 is fundamental here too, as it allows different types of mobile traffic to be given various levels of Quality of Service allocation whilst sharing the networking infrastructure. For example, voice data can be prioritised, so it will always be possible to make a phone call despite heavy data usage. There's also specific support with Carrier Ethernet 2.0 for the latest 4G/LTE mobile data standards, the bandwidth requirements of which make Ethernet-based backbone infrastructure even more essential. Here, Ethernet's ability to extend service beyond the WAN also make for improved service outside the wired Ethernet infrastructure itself, in the fast-growing mobile data arena.
Essentially, the utility of the intranet can be extended well beyond the traditional limits of the WAN. The increased bandwidth and simplicity go hand-in-hand with the increased demand for these features from cloud services as mentioned earlier, but also from video and voice data. Consumer usage of video now uses over half of total global Internet bandwidth. To combat this kind of bandwidth-hungry service, the ease of Ethernet implementation makes the infrastructure highly scalable. The same cabling can support services from 1Mbit/sec to 100Gbits/sec, with configuration at the end point able to alter the provision dynamically as required. This means that customers can be provided with bandwidth that accurately meets their needs. They won't need to pay for a high-throughput service they don't use, but it can readily be provided when they do require it.
The relentless growth of Carrier Ethernet
All these factors have have led to a phenomenal growth in the spending on Carrier Ethernet services since the Metro Ethernet Forum was formed in 2001. Infonetics expects a total of £110 billion to have been spent on Carrier Ethernet equipment between 2012 and 2016, arguing that £19 billion was spent in 2011 alone. The amount of global business bandwidth contributed by Ethernet services surpassed that of legacy systems in 2012, and the contribution is expected to reach 75 per cent by 2017. The growth rate is likely to slow as most legacy systems are replaced, but the increasing demand for data shows no signs of abating. According to Cisco, fixed Internet connection bandwidth requirements will have grown on average at a rate of 32 per cent every year between 2010 and 2015. Mobile data usage will have grown by an average 92 per cent every year.
Ethernet may not be the panacea for all our networking bandwidth woes. But it's clear that the flexibility and ubiquity of the technology, particularly since the advent of the Carrier Ethernet 2.0 set of standards, mean that it has a major role to play in coping with our exploding need for increased networking bandwidth over increasingly wide areas. Previous WAN technologies were mostly developed to satisfy the slow increase in demand for voice communications. The relatively rapid arrival of more generalised data needs in the last couple of decades, and the particularly throughput-hungry nature of video, cloud services and remote desktop virtualisation has meant that alternatives to previous WAN technologies were essential, and Ethernet has fitted the requirements most closely. But Carrier Ethernet 2.0 has also allowed Ethernet to go beyond merely upgrading the WAN, to provide LAN-like high-bandwidth services across even greater geographical areas, and to gain the full potential from the latest mobile data technologies as well.