TCP/IP Tutorial and Technical Overview - IBM Redbooks

networks in such a manner, organizations can now provide IP connectivity,
quality of service, differential routing, enhanced security, and a guarantee of
interoperability with other networks. Similarly, services continue to adopt IP
infrastructures. By doing so, these services benefit from open standards-based
interfaces, session control functions and management, logical subscriber
databases, and simplified interaction with other IP-based services and
applications.
Two implementations that exemplify the concept of IP convergence are
discussed in this part. Cell phone and public switched telephone networks
traditionally have implemented individual, and often proprietary, infrastructures.
However, as the need for reduced processing costs and increased scalability
have arisen, telecommunication providers have begun converging these services
and the networks across which the services are provided to the IP model,
comprising a protocol called Voice over Internet Protocol (VoIP). Similarly,
television broadcasting companies now need the capability of reaching an
ever-increasing population. Additionally, some of this population reside in remote
areas where the creation of an infrastructure to provide television is not feasible.
However, by implementing television networks using an IP model, access can be
provided to a much larger set of subscribers. Furthermore, wireless capabilities
using IP can be much more cheaply implemented, providing access to remote
areas. These concepts and more make up the protocol called IP Television
(IPTV).
As networks and services continue to converge, more and more resources will
become available through networks. Such an influx of networked data provides
numerous new security exposures, inherently increasing the need for stronger,
more flexible security models. Therefore, there have been many advances in
user authentication, data privacy, and data integrity. This includes adapting
existing technologies—and creating new ones—in the realms of not only
cryptology and authentication algorithms, but also in network access control.
Finally, as users and organizations become more dependent on the continually
growing number of networked resources, the importance of uninterrupted access
to these resources becomes paramount. To accommodate this, advanced
concepts of availability, scalability, and load balancing have arisen to ensure
access to resources 24 hours a day and 7 days a week. These concepts not only
include redundancy to account for hardware failure, but also embrace models of
workload distribution in order to ensure proper utilization of these resources.
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