The Hindu Business Line : <I>Go beyond the hub-and-spoke model</I>

Most companies have the traditional hub-and-spoke model to link up their computers. In such a model, there are hub locations at the corporate and regional headquarters, or a data centre, and point-to-point connections go from these hubs to branch offices.

"This type of network is very easy to design and implement, is relatively cost-efficient, and does not present any significant management concerns," write Chris Lewis and Steve Picavance in Selecting MPLS VPN Services, from Cisco Systems (www.ciscopress.com) .

As application needs change, it becomes necessary for companies to go beyond the hub-and-spoke model when, for instance, employees may look forward to `collaboration and knowledge sharing' to achieve better productivity, by tapping into `a global pool of resources'.

One option is to outsource the network design to a systems integrator or a professional services organisation; "the outsourcer can build a custom, optimised network for the enterprise based on the enterprise's locations and service provider's fibre paths."

An alternative is to use IP/MPLS VPN (Internet Protocol/ Multiprotocol Label Switching virtual private network) technology.

The latter allows enterprises to outsource the network's core. "Instead of requiring you to spend significant time building a plan for hubs and branches, the technology allows the enterprise to leverage a network with built-in latency optimisation." When using `private line, ATM (asynchronous transfer mode), or frame relay services', the selection of service provider is typically based on `speeds and feeds', meaning, evaluation based on the service provider's `network bandwidth, coverage, and cost'. But in IP/MPLS VPNs, selecting a service provider is a complicated exercise, note the authors.

A chapter is devoted to the implementation of QoS, short for `quality of service'. QoS refers to "the capability of a network to provide better service to selected network traffic over various technologies," as www.cisco.com explains.

"The primary goal of QoS is to provide priority including dedicated bandwidth, controlled jitter and latency (required by some real-time and interactive traffic), and improved loss characteristics. Also important is making sure that providing priority for one or more flows does not make other flows fail."

While discussing `enterprise security in an MPLS VPN environment' the authors explain techniques such as remote-triggered black-hole filtering, sinkholes, and backscatter traceback. The first uses "a routing protocol to quickly disseminate a route to Null0, which essentially drops the traffic that is part of an attack."

Sinkhole helps by diverting the attack traffic "to a safe place on the network," so as to avert collateral damage and aid analysis.

A contentious area is SLA or service-level agreement. "There should be more to an SLA than loss, latency, and jitter characteristics," advise the authors. "The SLA should define the metrics for each service delivered, the process each side should follow to deliver the service, and what remedies and penalties are available."

For example, "If you select a mouth-to-ear delay budget of 150 ms, you may determine that the codec and LAN delay may account for 50 ms, leaving you 100 ms for the VPN." Ideal read for your system priests, to achieve a better return on networks.

Violent video games

The debate is all about how to keep ultraviolent games out of the hands of children.

"Click. Click. Boom! Blood splatters and the bodies hit the floor." Thus begins a chapter on `violent video games' in Children, Adolescents, and Media Violence, by Steven J. Kirsh, from Sage (www.sagepublications.com) .

Worrying stuff, because violence doesn't stop with screenplay on PCs. "Erik Harris and Dylan Klebold, the teenagers who committed the atrocities at Columbine High School, preferred the violent video game Doom, and even designed additional levels for the game."

Video violence is a topic hot in news. For instance, www.delawareonline.com has a story dated March 20 about the violent and graphic images in the video game Grand Theft Auto: San Andreas.

The story speaks of a current debate in Legislative Hall on how to keep ultra-violent games out of the hands of children without "doing violence to the Constitution."

A report on www.newsday.com talks about how `25 to Life', a video game in which players win points for killing police officers, is drawing protests from local and national law enforcement groups. And San Jose Mercury News alerts, `Secretive new video game might inspire school bullies'.

Kirsh informs that in Germany virtualised human deaths violate decency standards. Therefore, "when a humanoid figure is shot during a video game, springs spurt forth as an indication that a robot was deactivated, as opposed to a virtual human life being taken." Australia bans video games `deemed unsuitable for public use'.

The world business for video games is said to be over $10 billion annually. Here are more alarming statistics: "The bloody version of Mortal Kombat sold seven times more units than the less violent version of the same game... During October 2004, Grand Theft Auto: San Andreas sold over two million units in just five days."

Kirsh opines that Sony could triple its video game console PlayStation partly because of improvements in "the game's processing speed, graphics, sound, and realistic representation of the human form." The original PlayStation could process 3,50,000 pg/s (polygons per second, a measure of graphics quality); PlayStation2 could achieve 66 million pg/s.

It was during the Nintendo era that abstract fighting and shooting got replaced by `more realistic and graphic violence,' chronicles the author. "In the ultra-violent video game series Mortal Kombat, the words `Finish him' preceded extreme depictions of brutality and gore, including crimson blood spurting after a decapitation, a torso being ripped in half, and a spine being torn from the body in which it once resided." Just the things that can make you wince!

After looking at a zombie's head explode on screen `in a splatter of green blood', the author wonders if colour can make a difference; for, "red connotes aggression, anger, and rage, while green evokes feelings of comfort and relaxation".

Quantitatively, however, the number of violent acts is unaffected by colour change, argues Kirsh. "The same number of decapitations, arms getting ripped off in a hail of bullets, holes appearing in the middle of torsos, and teeth gnashing into flesh will occur... Do we really want youth feeling comforted and relaxed when blowing things up?" Chilling read!

Tailpiece

"Boss is playing his favourite video game again... "

"Pink Slip?"

"Yes, and he has moved to the next level!"

Books2Byte@TheHindu.co.in