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Security – The New Priority

Individuals and enterprises rely heavily on telecommunications for all kinds of services, ranging from Internet surfing to complex business applications. Now - more than ever - a high degree of information integrity and data privacy are of the utmost importance. Unless the transmission media are secure enough to deny access to intruders, conventional methods of supporting information and transaction security - such as login-id and passwords - need to be re-examined.

Even with today’s advanced telecommunications networks, there must always be some kind of medium to carry the information from its source to its destination. This medium is tangible if there is wired-line access - as in traditional telephone networks, dial-up services, broadband and even fiber lines. But in the wireless world, the medium is intangible - which actually allows more scope for intruders, so that additional security measures must be put in place to protect the information transmitted.

Various techniques and protocols have been developed to help service providers supply a reliable and secure infrastructure, covering both wired-line and wireless access. Examples are:

  • multi-level access IDs and passwords for system administration, coupled with a detailed operation log for the telephone and wireless switch system;
  • information encryption through WEP (Wired-line Equivalent Privacy) in wireless LAN communications;
  • IPSec (IP Security) tunneling encryption IP-VPN (Internet Protocol, Virtual Private Network) implementation;
  • secured MPLS (Multi-Protocol Label Switching) network.

These all address concerns about security of information from the service providers’ perspective. But without the cooperation of service providers to ensure a robust and secure network, any attempt to provide security protection for customers is in vain.

Next Generation Network (NGN) – a new choice for business

Managed NGN has evolved from TDM and the packet data network

Traditionally, the telecommunications network evolved from the TDM (Time Division Multiplex) infrastructure, which is primarily designed to carry 64Kbps PCM (Pulse Coded Modulation) voice traffic. A T1 circuit can accommodate a maximum of 24 voice channels; but if it is used to carry data traffic in a clear-channel configuration, a bandwidth of 24 x 64Kbps or 1.536Mbps can be supported. Though there is an end-to-end bandwidth guarantee for this TDM-based data service, there is wastage of network bandwidth resources if no data are being transmitted from one end to the other, as the circuit bandwidth still has to be reserved.

As the technology has evolved however, data packet technology has emerged, to enable effective bandwidth usage. Examples, designed primarily for speed, are:

  • X.25 – a packet switching technology with a range of 1.2Kbps to 256Kbps;
  • Frame Relay (F/R) – with a range of 64Kbps to T1/E1 (1.5Mbps and 2Mbps);
  • ATM (Asynchronous Transfer Mode) – for 25Mbps, 45Mbps, 155Mbps & 622Mbps.

With the popularity of Ethernet technology at 10Mbps, 100Mbps, 1Gbps (1,000Mbps) and even 10Gbps, the cost of the hardware chip has fallen over the last decade. There has been extensive adoption of Ethernet interfaces for equipment like routers, switches, servers, desktop computers, notebooks and even PDAs. And there is no sign of any improvement on the Ethernet as the most cost-effective networking technology.

With this strong foundation, it is obvious that more and more applications may be expected for the Ethernet network. It has catalyzed the convergence of the voice/data network and the evolution of a new stage of the Next Generation Network, which is based on IP technology with Ethernet as the link layer protocol.

NGN as the platform for both IP & voice telephony services

Technological development always follows a learning curve; new ideas or concepts build on past experience and well-proven techniques. And the successful merging of the telephony service into the IP network has to be backed up by a proven set of protocol packs, to handle the signaling and real-time voice-to-data conversion.

NGN, which accommodates both IP data traffic and IP telephony services within the same network, has been made possible by using various CODEC (Coder-Decoder) systems:-

  • G.711 (64Kbps for each voice channel);
  • G.729 (8Kbps for each voice channel); and
  • G.723 (6.3Kbps/5.3Kbps per voice channel)

coupled with several different voice gateway signaling protocols:-

  • H.323;
  • MGCP (Media Gateway Control Protocol);
  • SIP (Session Initiation Protocol); and
  • H.248.

From the customer’s perspective, using IP telephony over the NGN platform does not change classic voice features such as Caller Name Display, Call Holding, Call Hunting, Call Waiting, Call Forwarding, or Call Conferencing, as in the traditional TDM-based POTS telephony system.

Enhancing NGN to provide a highly secure network infrastructure

The benefits of NGN are not limited to the integration of data and voice; the name Next Generation implies there is something new, in addition to merging what we have today.

Applications such as video conferencing, e-commerce and infotainment are clearly the up-coming revenue-generating sources for service providers. Executives today are moving towards better use of advanced network technology for their business operations. Business units no longer need to be located in the same physical area, but can be scattered around the world to capitalize on lower-cost labor, natural resources and office space.

In Hong Kong, it is becoming clear that entrepreneurs are moving their manufacturing plants into Mainland China, while maintaining sales activities in Hong Kong. And some of Hong Kong’s large corporations are setting up of branch offices in India for software development work. To facilitate this kind of expansion, a secure network linking all the business units with voice, fax and data services is a must. Now that NGN is available, the next step is to derive a technology that provides a secure infrastructure for the network. The same network must be flexible enough for future business growth, which is likely to demand higher bandwidth, and support for applications such as multimedia services.

An excerpt from a rewritten article.


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John Clutterbuck, DipCW