In this semester, you
will learn about Cisco IOSŪ features and technologies that will
enable you to support the following key scalable internetwork
characteristics:
Reliable and available --- This includes being dependable and
available 24 hours a day, 7 days a week (24 x 7). In addition,
failures need to be isolated and recovery must be invisible to the
end user.
Responsive --- This includes managing the QoS needs for the
different protocols being used without affecting a response at the
desktop. For example, the internetwork must be able to respond to
latency issues common for Systems Network Architecture (SNA)
traffic, but still allow for the routing of desktop traffic, such as
Internetwork Packet Exchange (IPX), without compromising QoS
requirements.
Efficient --- Large internetworks must optimize the use of
resources, especially bandwidth. Reducing the amount of overhead
traffic, such as unnecessary broadcasts, service location, and
routing updates, results in an increase in data throughput without
increasing the cost of hardware or the need for additional WAN
services.
Adaptable --- This includes being able to accommodate disparate
networks and interconnect independent network clusters (or islands),
as well as to integrate legacy technologies, such as those running
SNA.
Accessible but secure --- This includes the capability to
enable connections into the internetwork using dedicated, dialup,
and switched services while maintaining network integrity.
Each of these characteristics is discussed in more detail in the
following sections.