Infrastructure IX - Next Generation Network (NGN)

The Telecommunication Standardization Sector of International Telecommunication Union (ITU-T) has made recommendations on Next Generation Network (NGN) which is conceived as a concrete implementation of the Global Information Infrastructure (GII). Throughout the years, different study groups have published the results of their researches and developments in this regard.

ITU-T (2004) note that ‘the target of NGN is to ensure that all elements required for interoperability and network capabilities support applications globally across the NGN while maintaining the concept of the separation between transport, services and applications.’

I quote the definition of NGN from ibid (2004, p.2)

‘A packet-based network able to provide telecommunication services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport related technologies. It enables unfettered access for users to networks and to competing service providers and/or services of their choice. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users.’

Nowadays, there are many different NGN communication operators such as PSTN (Public Switched Telephone Network), ISDN (Integrated Services Digital Network) and GSM (Global System for Mobile communications), and they are internetworked by means of gateways. We see the applications of them in the following manner, the communication devices connected to NGN will include analogue telephone sets, fax machines, ISDN sets, cellular mobile phones, GPRS (General Packet Radio Service) terminal devices, SIP (Session Initiation Protocol) terminals, IP phones through PCs (Personal Computers), digital set top boxes, cable modems, etc.

The NGN is characterised by the following fundamental aspects (ITU-T 2004, p3):

Packet-based transfer

Separation of control functions among bearer capabilities, call/session, and application/service

Decoupling of service provision from transport, and provision of open interfaces

Support for a wide range of services, applications and mechanisms based on service building blocks (including real time/streaming/non-real time services and multi-media)

Broadband capabilities with end-to-end QoS and transparency

Interworking with legacy networks via open interfaces

Generalised mobility

Unfettered access by users to different service providers

A variety of identification schemes which can be resolved to IP addresses for the purposes of routing in IP networks

Unified service characteristics for the same service as perceived by the user

Converged services between Fixed and Mobile networks

Independence of service-related functions from underlying transport technologies

Support of multiple last mile technologies

Compliant with all Regulatory requirements,
for example concerning emergency communications and security/privacy, etc.

The aspects have been illustrated the characteristics of NGN. Needless to say, the scopes of ITU-T are very wide and in-depth. But I myself find it the most conclusive aspect of NGN is to generalise mobility, which will allow a consistent provision of services to a user. In other words, the user will be regarded as a unique entity when utilizing different access technologies, regardless of their types (ITU-T 2007, p.3).

I only focus the discussion on Generalised Mobility. In the future, mobility will be offered in a broader sense where users may have the ability to use more access technologies, allowing movement between public wired access points and public wireless access points of various technologies. It actually means that this movement will not necessarily force an interruption of an application in use or a customer service. However, this requires significant evolutions of current network architectures. Enabling more transparent fixed-wireless broadband communications and mobility across various access technologies appears as a major issue (ibid 2004, p.7).

Therefore, the ICT industries are achieving this objective. Gohring (2007) reports that RIM plans to issue a new model of BlackBerry with both cellular and Wi-Fi wireless capabilities as well as Motorola and Nokia were both selling phones with Wi-Fi and cellular aimed at business users last year. This indicates that the developers and manufacturers of mobile devices need to enable their products to be compliant with multiple operators and multiple access capabilities.

References

Gohring N 2007, ‘RIM plans Wi-Fi/cell phone BlackBerry’, Computerworld Hong Kong Daily, posted 28 May 2007, viewed 15 September 2007, <http://www.cw.com.hk/computerworldhk/article/articleDetail.jsp?id=429669>.

ITU 2005, home page, ITU-T’s Definition of NGN, updated 19 December, viewed 13 September 2007, <http://www.itu.int/ITU-T/ngn/definition.html>.

ITU-T 2004, ITU-T Recommendation Y.2001 (12/2004) - General overview of NGN, Series Y: Global Information Infrastructure, Internet Protocol Aspects and Next-Generation Networks, Next Generation Networks – Frameworks and functional architecture models, Geneva, Switzerland.

ITU –T see Telecommunication Standardization Sector of ITU

Infrastructure VI - Disaster Recovery

Last time I mentioned about Contingency Plan. Today I further the discussion of it in a practical sense and I would bring up something about Disaster Recovery (DR) which is actually a kind of contingency plans.

The need for DR is to ensure the business continuity whenever the crisis arises such as fire, power failure, storm, disease outbreak (e.g. SARS) and any other unexpected events which can damage your business, and your precious data.

Smit (2007) reports that:

‘According to the Meta Group, the average cost of an hour of downtime for data centre applications is $330,000. According to the Strategic Research Corp., if that data centre belongs to a credit card authorization company, the loss jumps to $2.6 million. And if it belongs to a brokerage house, it climbs to $6.5 million. One day of lost productivity costs a company an average of $432 per employee.’

Without doubt this is a great loss to a company. Don’t expect your clients would understand your difficulties and accept your apologies. The best solution is to plan ahead before the disaster occurred. Reducing the downtime means cutting down the loss. But how?

Ibid (2007) has given us the directions to ensure high availability and business continuance.

Protecting, replicating and backing up data

First of all, we need to build up a high-capacity and low-latency data centre, which is interconnected to MAN (Metropolitan Area Network) and WAN (Wide Area Network). This can enable zero-data-loss data mirroring to protect user sessions, prevent transaction loss, and support automatic failovers between mirrored sites. SAN (Storage Area Network) technologies which enhance the distance, security, bandwidth utilization of replication and backup to remote sites, however it has not been really popular. In addition, technologies such as write acceleration, tape acceleration and server-less backup reduce latencies, extend distances and reduce application impact of storage replication applications. Moreover, it needs support for business continuance applications, especially those that provide replication and data protection.

sourced from Javvin

Enhancing application resilience

Companies can remove single points of server failure by deploying high-availability clusters or load-balancing technology across Web and application servers. Apart from that, connectivity can be extended between clusters in different data centres to protect against major disruptions. Achieving this type of redundancy requires a high-speed, low-latency metro network.

Ensuring user access

Companies can employ technologies such as VPN to allow users from branch offices and telecommuters to reconnect to applications quickly as soon as they are up and running. In addition, technologies such as global site selectors can allow users to manually or automatically connect to the most available web application available at any given time. In the case of a disruption in any one application environment, users continue to have access to the alternate site.

Needless to say, we all realised the devastating impact of 911. It just happened once in the past 6 years. Do we really have to focus on this incident too much and then, spend tens and thousands dollar on the above systems. Some may not be used even once in 10 years. The answer is absolutely. I still remember the disaster happened around 6 years ago. Due to the disorder of the fire sprinkles of an office on the high floor, it flooded the whole commercial building with water and thereafter, the power was suspended for a day. At that time, what we could do was to shut down all our mission critical servers before the UPS (Uninterrupted Power Supply) has been worn out. This action was to protect our servers and data. Lucky we had installed the UPS for all mission critical servers.

You can probably imagine how big the loss was caused by this incident. Very unlikely, DR is able to fully eliminate the loss but at least, it can lighten it. Anyway, DR is totally a choice of investment. What is your choice?

To be continued

References

Javvin, ‘Metropolitan Area Network and MAN Protocols’, Javvin Technologies, Inc, California, <http://www.javvin.com/protocolMAN.html>.

Javvin, ‘Storage Area Network and SAN Protocols’, Javvin Technologies, Inc, California, <http://www.javvin.com/protocolSAN.html>.

Javvin, ‘WAN: Wide Area Network’, Javvin Technologies, Inc, California, <http://www.javvin.com/networkingterms/WAN.html>.

Smit A 2007,’Data centre safety measures protect business’, Enterprise Innovation, Technology, posted 28 August 2007, viewed 8 September 2007, <http://www.enterpriseinnovation.net/article.php?cat1=2&id=1847>.