QoS and its relationship to bandwidth
management is becoming more critical in order to deliver network
performance while not investing too heavily into equipment.
Quality of Service is a way to mark network data packets in
various prioties - or classes - across a network. This is
important, because more and more real time traffic - such as Voice
over IP (VoIP) and video are increasingly flowing across data
networks. Also, large SMS flows of traffic - like anti-virus
updates - can crowd out mission critical traffic. QoS
provides a tool to protect your most critical applications.
But as QoS has become more of a reality, the price of bandwidth
continues to fall. This leads most enterprises to weigh the
extra costs of providing sophisticated infrastructure to provide
advanced routing protocols against the less and less expensive
costs of bandwidth. After all, given huge amounts of
bandwidth, QoS becomes less and less of an effective tool.
It is only in network bottlenecks where QoS is required.
If large speeds can be configured throughout a network, traffic
shaping, weighted fair queing and any other sophisticated routing
protocols are not needed. A network refresh is then not
needed to procure the latest routers and switches to run QoS
But a robust and effective QoS deployment does allow maximum
use of existing bandwidth. Since most traffic is not
real-time, and some delay is acceptable, a quality of service
packet scheme can maximize fixed bandwidth. Rather than
upgrading circuits to larger speeds, QoS allows for the efficient
use of smaller circuits.
There are lower speeds however when QoS is just not effective.
For instance, any circuit below 256k QoS routing is just not going
to make much of a difference. But again, given the declining
price of bandwidth, an upgrade to a WAN circuit up to the
underlying access of T1 is typically not cost prohitive compared
to the cost of a new router.
Increases in router processing, which allows for more
sophisticated QoS service, versus the declining price of bandwidth
requires careful analysis of how much investment in either will
provide for the best network experience.