Friday, August 24, 2007

Bandwidth the Key to Network Choices

Communication constraints the biggest inhibitor to cutting costs by using VoIP.

COMPANIES have the choice of continuing to run their voice networks separately, run interbranch calls over their own wide-area network (WAN) or get a high speed internet service to act as both data and voice provider.

In an in-house scenario, a company could implement a Voice over Internet Protocol (V0IP) solution to route voice calls for interbranch communication between employees over the company-owned WAN, using traditional telephones.

The next step would be to add an IP telephony solution that integrates voice capabilities into PC applications.

For example, the user could then make an interbranch voice call by selecting an option in Outlook and speaking into an IP phone or speaking directly into the PC using a headset or built-in microphone.

"The latest laptops are coming out with a built-in, high-quality microphone so users can speak directly into it when making VoIP calls," says Danie Nel of Nebula.

Once regulations are in place that allows interconnection agreements between network operators and service providers, users will also be able to make VoIP calls from their PC to any subscriber locally and globally across different networks.

From this information we see there is merit in companies outsourcing interbranch voice and data communication functions to a service provider that will provide the WAN infrastructure, manage the service and route the traffic to relevant parties over their network.

Dave Gale, business development director at Storm, says bandwidth constraints are the biggest inhibitor to the take-up of VoIP. With a VoIP service, a gateway device is installed between the company’s PBX and the Telkom line and the signal is routed over a data line to the service providers network. This is where the bandwidth challenges starts.

Companies typically use a dedicated Diginet leased data line to connect to the service provider, because it is the only way to get consistent throughput and guaranteed bandwidth, says Gale.

Most companies use a 128 kilobits per second (kbps) leased line, which costs about R3 000 a month and is expensive for smaller businesses. With a 128kbps line a service provider like Storm has to optimise the bandwidth between the customer and its own network, and within its own network, tightly.

There are advantages in using the same leased line for data when it is not being used for voice, but this situation needs to be managed so the data traffic does not impede the quality of the voice calls. It is necessary to have an express speedway for voice and later for video.

A big enough bandwidth pipeline will ensure that the quality of VoIP calls can be better than when communicating over the public switched telephone network. But in a bandwidth-lean environment, South African companies and service providers need to optimise bandwidth usage or purposely downgrade the VoIP quality to a level that is still acceptable.

Jacques du Toit, sales and marketing director for Orion Telecom, says traditional PBX suppliers are selling companies on the benefits of attaching the equipment to the local area network (LAN) and carrying voice calls over the data network using VoIP.

However, the leased line is owned by Telkom and the company is at risk by having all its eggs in one basket if the link goes down, says Du Tolt.

It is better to have separate external voice and data lines than to run voice on the main wide area data network, because these links are unlikely to both go down at the same time.

It is important for a company to ensure its internet service provider can guarantee bandwidth capacity from origination to destination when voice calls are travelling over its network. Separate agreements should be drawn up for voice and data services.

Stand apart with Storm Telecom: a voice and data provider that makes sure your business stands out from the crowd. Storm offers a range of products and services that are essential to the success of your business.


http://www.amazines.com/Computers/article_detail.cfm/166581?articleid=166581