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… |
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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