What is it?
In recent years private wide area networks, and those based on leased lines, have been steadily replaced by virtual private networks. And the many competing Wan technologies are beginning to converge around the mighty Internet Protocol.
Some of the world's biggest telecoms providers and network equipment suppliers have come together to form the Multiservice Switching Forum, and are attempting to define the open-architecture, multisupplier, multiservice switching systems on which the networks of the future will be based.
Where did it originate?
The MSF was formed in 1998, and its members make up an alphabet of telecoms companies around the world, from Alcatel, Belgacom, BT and Cisco to China's ATE Corporation.
What's it for?
Traditional Wans exist in an arcane world where choices and distinctions must be made between packet switching and circuit switching, and frames and cells. For example, asynchronous transfer mode is a cell-switching and multiplexing technology designed to combine the benefits of circuit switching (constant transmission and guaranteed capacity) with those of packet switching (flexibility and efficiency for intermittent traffic).
On the other hand, Frame Relay is a packet switching network, used for carrying large volumes of data, and latterly voice. Frame Relay is a "cloud-based" technology: in place of a complicated mesh of fixed lines, any site can connect to any other other site connected to that cloud.
A multiservice switching system may be frame, cell or packet-based.
What makes it special?
Incumbent telecoms providers have billions of pounds invested in circuit-switched networks. But data has overtaken voice as the main traffic, and circuit-switched networks are not good at handling data. Circuit-switched price/performance doubles every four or five years; for IP networks it is every 18 months.
Next generation IP cuts network building costs substantially. Operating costs are lower for IP, since it is a single network, with one lot of management requirements for both voice and data.
How difficult is it to master?
Convergence on IP means that people from data and voice backgrounds will increasingly use the same skills. But there is a culture gap: the almost-good-enough performance and frequent downtime we are used to from data networks will not be acceptable with voice.
Where is it used?
IP networks can support data, voice and multimedia. Quality of service still has a way to go, but voice over IP no longer makes you sound like Mickey Mouse with asthma.
MSF with M'decins Sans FrontiŠres, though both were set up to deal with some pretty horrible situations.
What makes it hot?
Over the past year the number of job adverts asking for Wan expertise grew by 32%, according to the Computer Weekly/SSL survey. However, the Office of National Statistics' Labour Force Survey found 18,000 telecoms engineers were out of work towards the end of 2002.
Not many people know that
Cell switching has nothing to do with moving Jeffrey Archer to an open prison.
What's coming up?
Multi-Protocol Label Switching has the potential to overcome many of the scalability, performance, management and integration challenges facing telecoms carriers as they develop IP networks and services.
The big network equipment suppliers provide certification in Wan technologies.
Rates of pay
Wan engineers and analysts receive £28,000 to £40,000 and a lot less for support. Network provisioning - predicting the amount of bandwidth that will be needed - is a sought-after skill.
This was first published in May 2003