Five networking technologies to watch

In the fast-paced world of networking, technology is constantly evolving to meet demands from business for greater bandwidth....

With the explosion of the Internet and use of IP networking within business, suppliers have been busy working on ways to make networking cheaper and easier to deploy. That means users face a number of fresh concerns. First, the popularity of IP networking has resulted in a shortage of IP addresses. Second, demand for greater bandwidth from businesses has caused telcos to look at cheaper wide area networking technologies. Businesses now using wireless LANS (WLANs) face the prospect of running obsolete equipment as the current 802.11b standard for WLANs is superseded by 802.11a. Finally, network suppliers are supporting an emerging standard for power over LAN, which promises to make it easier for users to plug their wireless devices into a network. IPv6 has been a target for the IT industry for almost a decade now. Driving this standard has been the recognition that IP addresses for public use are running out and this is exacerbated by the increase in devices that need an IP address. It also aims to address several significant shortcomings with the current IPv4 standard. The need for more address spaces is often cited as the primary reason for moving to IPv6 although the change to the address space is more than just adding a larger pool. The IPv6 address mechanism is designed to allow addresses to be split into two parts, a unique identifier for a device and a location of where that device is connected to the network. In the mobile phone industry, this is seen as being a big driver to control access and provide localisation services. For corporate IT departments it would mean that any device within a corporate network would be uniquely identifiable. This could boost security as it would be possible to track devices physically. Versions of IPv6 exist for the leading operating systems and all networking vendors are trialling their own IPv4/IPv6 bridges which will be required during the transition from one standard to the next. The major telecom operators are deploying IPv6 in their network backbone and at EU level there are several projects to install IPv6 on the inter-governmental network. Equipment suppliers such as Cisco, Ascend and Nortel already support IPv6 and leading network card vendors have been shipping IPv6 drivers for some time. With the availability of IPv6/IPv4 bridges there is no reason why corporate network teams cannot deploy IPv6 today in a staged deployment without affecting their existing networks. Optical networking involves transmitting light down an optical fibre. In DWDM, rather than use a single beam of light to transmit data, the light is split into its constituent colours. Each colour (or frequency of light) is then used individually to transmit data, thereby increasing the amount of data a single optical fibre can transmit. This technology is being widely deployed by various telecom carriers around the world. They see it as a significant way to reduce the cost of telephony. The cost of network expansion is substantially reduced by DWDM as telcos do not have to lay new fibre. Other savings for operators include lower management costs and fewer points of failure. With mass-market suppliers such as Intel developing optical components equipment costs are set to fall dramatically. For the user the cost of bandwidth provided over DWDM is expected to fall as a consequence. One of the advantages of DWDM is that it is protocol independent which allows operators to move voice and data across the same network. For operators building large scale Virtual Private Networks (VPN), DWDM allows them to provision services to several customers over the same fibre without risk of compromising security. Power over LAN (POL) uses network cables to transmit electricity over a standard local area network. Its primary use is for providing both power and data to network devices using just a single cable. One of POL's attractions is that it allows users to install network devices such as wireless network access points in areas where there is no existing power, such as in roof spaces. A standard for POL is being developed by the IEEE 802.3af committee. This is aimed at network equipment running at 10Mbit/s and 100Mbit/s using standard category 5 cabling. As a result users should not need to install or change existing cabling in order to take advantage of POL. However, there may be problems with certain types of network equipment such as hubs and patch panels. The standard limits the amount of power that can be delivered to just 15.4W (44-57v), which some suppliers believe is ample to run a large number of network devices including, potentially, charging laptop computers. However, there are suggestions from some wireless suppliers that more needs to be done to ensure protection against surges and overheating of devices, especially if they are placed in areas that are difficult to monitor. Suppliers such as PowerDsine, Cisco, Symbol, 3Com, Ericsson, Agere (Proxim) and Intel are currently shipping POL enabled equipment. Providing support for POL will require network equipment manufacturers to make some changes to their existing products. So it is likely, therefore, that until there is some demand from users smaller suppliers will wait and see. 802.11g is an attempt by the IEEE standards group to bring together two wireless standards. Its aim is to create a high-speed network that will be backwardly compatible with existing network equipment. The technical challenge for the standard is that 802.11g needs to support the two existing wireless WAN technologies: 802.11a and 802.11b, which use two, separate radio frequencies. The 802.11g standard proposes a single radio frequency. If successful, existing 802.11b users will have a transition path to high-speed (>50Mbit/s) wireless networking without having to replace their existing wireless infrastructure. With 802.11a products now being rolled out, suppliers are unlikely to support another wireless standard so soon. The industry is only now starting to deploy wireless access points that support the two existing standards - 802.11a and 802.11b. No suppliers are yet supporting 802.11g. As and when products become available it is likely manufacturers such as Cisco, Symbol and Agere, who are shipping 802.11a today, will lead the way with 802.11g products. During the early push to get broadband deployed, the idea of transmitting data over power lines was extensively explored. The technology worked by using the electrical distribution network to provide Internet access as well as electricity. It required a box placed at the end-user's premises to separate electrical signals from data. The speed that users can expect to receive is around 1Mbit/s which is comparable to the highest speed ADSL and Cable connections today. So far, the take up of Digital PowerLine - as the industry calls it - has been extremely limited with the USA and Germany being the two biggest markets. One of the reasons for this is persuading consumers that it is safe and can compete against existing technologies. Prior to wireless LAN technology Digital PowerLine was positioned as a way to create small office and home LANs. This failed due to price and electrical safety concerns. Industry body the HomePlug Powerline Alliance ( ) boasts around 30 adopters of the technology, among them Ericsson, Linksys, HP and Accton. In the fast-paced world of networking, technology is constantly evolving to meet demands from business for greater bandwidth. selects five technologies that promise to play a major role in tomorrow's network infrastructure designs.

Networking with IP v6.0

DWDM (dense wavelength division multiplex)

Power over LAN

802.11g Wireless LAN

Networking over power lines

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