The three phases of network development:

1. Host-based
2. Client-server
3. Information

Three technology barriers to Information Networks.

1. Operations and management
2. User access and usability
3. Digital video

User access and usability.

1. Intuitive, interoperable user interfaces
2. Intelligent agents
3. Information fusion
4. Information preparation
5. Authentication and security
6. Service portability and transparency

The three phases of network infrastructure evolution are:

1. Host-based networks: Characteristics: circuit-based, protocol-dependent, centralized, connection-oriented. Applications: Mission critical, constant use, low bandwidth, some quality of service (QoS).
2. Client-server networks: Characteristics: router-based, protocol-independent, distributed, connectionless. Applications: Departmental applications, sporadic use/bursty, medium bandwidth, few QoS constraints.
3. Information networks: Characteristics: switch-based, protocol-independent, collaborative, connection and connectionless. Applications: Collaborative applications, constant use/bursty, high bandwidth, variable QoS constraints.

Three technology barriers that must be addressed to realize an information network.

1. Operations and management: A large and often unrecognized barrier to the exploitation of information networks is the lack of cost-effective solutions for operations and management. In 1994, US labor costs associated with the operation and management of private information networks was estimated to be more than $200 billion. The information infrastructure of the future will provide not only connectivity but information services as well. A paradigm shift will be necessary for the operation and management of the future information network.
2. User access and usability: Lack of a common user interface could turn the vision of an information services network into a nightmare if users are unable or unwilling to use new services and products. Six issues need to be considered.
3. Digital video: This will by no means be routine or inexpensive. Requirements are: infrastructure capacity, interoperability, tools for creation and management.

Six user access and usability (computer user interface, CUI) issues that need to be addresed by software engineering.

1. Intuitive, interoperable user interfaces: Tomorrow's user interface must improve on GUIs, integrating multimedia search with text and database queries. It must also support all potential interface techniques, including keyboard, mouse, voice, and pen.
2. Intelligent agents: The huge amount of information available will require intelligent agents and filters that can learn user preferences, deal with multimedia data, and use standard methods to capture, represent, and communicate information.
3. Information fusion: For the information to be useful, content-retrieval technology must combine the results, in a meaningful way, from query servers running different search engines against very large multimedia collections.
4. Information preparation: Generic tools for authoring and presenting multimedia information should enable nonspecialist users to handle information from a variety of sources.
5. Authentication and security: The information network will require security and authentication techniques that are scalable and applicable to heterogeneous environments. Techniques for document authentication and copy protection must be further developed and applied to multimedia objects. All forms of payment, including subscriptions and pay-per-use, should be supported in a common framework.
6. Service portability and transparency: This heterogeneous, multisupplier network must hide its complexity from the user. The user should be able to obtain services without concern for the details of the networking environment, the geographic location of the information sources, or other participants.

Annotation: Anniversary Issue, 50 Years of Computing