BANDWIDTH: Dreaded ‘C’ Word Spoils Party

George Gilder, the famed author of Microcosm and Telecosm, said that

bandwidth would be free and infinite. Many argued that uptime would be more

important than availability, and rightly so.

Already, heavy e-com revenue losses are being reported worldwide due to

bandwidth related problems. Even though paucity of bandwidth is widely

acknowledged as the major cause, inefficient utilization of bandwidth is also a

key factor. Moreover, Internet traffic increases in proportion to available

bandwidth, as fast as it is added; so delays and choking of networks are

inescapable. And then, there are times when traffic increases to extraordinary

proportions, during a major political or sports event or calamity.

A QoS appliance…

Is of the greatest use to service providers and large enterprises Sits behind the router at the LAN-WAN interface Measures the expected performance of a TCP/IP network Manages traffic congestion Frees up bandwidth for top-priority applications Removes latency for voice applications

All this points at the Internet protocol’s inherent weakness in handling

enormous traffic. It is in such situations that quality-of-services (QoS)

appliances have a crucial role to play. They enable e-business applications–including

e-commerce, intranet access, Internet browsing and multimedia streams–to share

bandwidth with legacy and other existing applications, while ensuring that

response time for business-critical applications is always protected. Already

companies like Sitara Networks have moved in this space to provide solutions to

enterprises, ASPs, ISPs to deploy e-business applications on existing networks.

The need for QoS

The new-breed Internet applications such as multimedia are

bandwidth intensive. The concern, however, is not merely the capacity and the

high volume of traffic, but its changing nature too. The traffic today includes

many new IP-based applications that vary tremendously in their operational

requirements. A QoS network refers to a network that is capable of handling

traffic that meets the service needs of different applications. This requires

fundamental traffic handling mechanisms on the network, the ability to identify

traffic that is entitled to these mechanisms and the ability to control these

mechanisms. The functionality of QoS can be perceived to satisfy network

administrators and applications. This would require fundamental traffic handling

and other modes of accepting valid data. Says Sridhar Manickham, CTO, Sitara

Networks, "As the demand for networked real time grows, so does the need

for shared networks to provide deterministic delivery services. Such delivery

services demand that both the source application and the network infrastructure

have capabilities to request, setup and enforce the delivery of data".

Sitara’s QoS appliance

Sitara Networks has built an appliance named QoS Works that

allows for bandwidth management without disrupting the existing network.

Integrating this appliance into the existing network involves the construction

of a generalized QoS framework. After that, the QoS Works capture specific

application requirements and maps those. The specifications encompass the

requirement for performance, synchronization, level, cost of service and QoS

management. These requirements are used to derive resource requirements for

entities such as computation, communication and storage. They are successfully

mapped into quantitative QoS parameters relevant to various system layers that

can be monitored and controlled.

Enterprises have started realizing the importance of managing

limited bandwidth. QoS Works addresses, to a certain extent, the issue of

network congestion causing critical services to become unresponsive. Says

Manickam, "Enterprises often use the same bandwidth for both internal and

external connections because additional bandwidth is expensive today. This is a

perfect situation where the art of managing bandwidth comes to the fore".

QoS Works is capable of managing 45 Mbps of bandwidth. Along with a command line

interface, it has a Web-based interface, to give network administrators the ease

and flexibility of managing. Towards this end, Sitara also has QoSDirector, a

fully integrated central policy management software for the QoS Works network

management platform. It allows large enterprises to configure, monitor, set

policies and optimize network traffic management through a single, centralized

solution. QoSDirector runs on the Sun Solaris platform and supports

authentication, authorization and encryption.

Even though the prices of bandwidth are dropping globally,

newer and diverse applications are growing and putting increasing demands on

existent networks. So, companies have to figure out a way of integrating

applications and networks to effectively use bandwidth with legacy and

mission-critical applications.

Manickam feels there is a tremendous opportunity in this

space and Sitara has the advantage of being an early entrant. The company has

already launched QoS solutions aimed at service providers and large enterprises

seeking to expand business opportunities through deployment of new applications

and services. The profitability and survival of these enterprises depends on

their ability to effectively manage, offer on-demand access and ensure

uncompromised delivery of applications and services to their customers.

Prioritizing applications

It is often asked if developing enterprise policies and

configuring QoS features is worth the effort. Can’t merely over-positioning

(having increased amounts of bandwidth) be enough?

The answer primarily lies in the nature of TCP applications

and the economies of scale in deploying additional bandwidth. Each application

requires different services from the network and behaves in different ways.

Agrees Vijay Parikh, VP and GM, IP POP systems, business unit, Cisco Systems,

"Over-positioning is not a viable alternative for the network handling the

specific demands of applications." He adds, "For instance, certain

applications like Oracle, SAP and PeopleSoft ERP can tolerate peak bursts that

transcend the existing capacity. But it cannot be sustained for a long period

and at that point the applications could behave erratically and flood the

network capacity". One application that needs to be particularly considered

is "voice". Voice requires network services with low latency, minimal

interference and no packet loss. It is the delay and packet loss that affects

voice applications; voice traffic in itself does not need much bandwidth.

Enterprises could take care of many of these diverse

application requirements if they could throw unlimited bandwidth at their



networks. At some point, having a large pool of bandwidth would eradicate
network congestion, which is the crux of most service-related problems. But in

doing so, companies would need to disregard the high recurring costs (which

could run into lakhs of rupees every month). The solution therefore lies in

implementing solutions that make optimal usage of available bandwidth. This is a

viable way to work within an environment of finite resources and to condition

the network to give each application the resources it needs to perform properly.

QoS is not about creating bandwidth–availability of

bandwidth is a minimal requirement. It is all about managing the available

bandwidth according to the application demands and network management settings.

With Internet becoming de rigueur of businesses worldwide, the need for

accommodating newer applications calls for effective bandwidth management. QoS

could just be the solution enterprises are looking for. DQ