Describe Networking

Describe the networking configurations to allow interoperability across the Agency.

	A-TARS - Integrated Technology Descriptions - Technology Boundaries Descriptions - Platform, Equipment, Solutions Reference Set - Agency-Wide System Properties - TRM Descriptions - Networking Reference Set - AIS Design and Implementation Info. - Ancillary Design Info. - Technical Architecture Work Plans and Direction - Strategic Analysis and Data - Changes
Develop Networking Descriptions Update Networking Descriptions		- A-TARS: Networking Reference Set - Ancillary Design Info. - Status - Changes
	- Networking Specialists - Other Technical Specialists

Introduction

These activities create and update the Networking Reference Set descriptions. This portion of the A-TARS describes the network design and specifies essential characteristics, assumptions, and guidelines for networking the Agency computing platforms within and across Agency boundaries. This is the foundation for interoperability between the computing platforms and the basis of managing and evolving the network applications.

The network design evolves with other parts of the A-TARS. The Technology Boundaries Descriptions and the Integrated Technology Descriptions provide the big picture for the network design and are adjusted to harmonize with network design concerns, such as security or performance. The Platform, Equipment, and Solutions Reference Set provides detail on the existing computing platforms capability and is updated as networking equipment and the capability of the attached computers are upgraded.

TANF Example: Most state HS Agencies rely on a state-wide telecommunications and networking organization to provide access to the state network backbone. State-level requirements and conventions may be imposed on the HS Agency for security (e.g., who owns the firewall to access the network), IP addressing (blocks of addresses for publicly accessible nodes), and statewide services such as e-mail. This may effect all layers of the network design (application through physical connections). This can be a significant challenge when tens of thousands of users may be affected, spread across hundreds of remote sites. Network management issues such as the ability to quickly identify, diagnose, and correct network related problems across several providers is a priority as states move to 24x7 access on the internet.

Architects will have to address interoperability with external entities not only at the networking level, but at the application level. For example, FTP based file transfer to exchange health care provider information via batch updates may give way to online access via a service interface. Also, as more information is exchanged electronically with external service providers, technologies to ensure privacy and authenticity of a communication or document will be incorporated into the network design (i.e., nonrepudiation). Architects will therefore have to form cross organization working groups and manage cross organizational interfaces.

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Activities

Consolidated guidelines are available to perform the following key activities:

Develop Networking Descriptions. These actions build the network design and specify essential characteristics by iterating through the following actions:
- Evaluate the networking capability required of the applications for each type of platform, consulting the Integrated Technology and Technology Boundaries descriptions. This establishes the objectives of the network that must be optimized, such as bandwidth, response times or security.
- Determine the logical infrastructure requirements to provide the desired objectives, such as the current or expected capability of the platforms (e.g., legacy computers, terminals), locations, and organizational (data ownership/sharing) considerations. This helps define network segments, routes, and types of links required.
- Select the technologies to use based on the understanding of the distributed application needs and the platforms, such as use of LAN or WAN technologies and protocols. This includes identifying the network-specific services (e.g., DNS) by considering the items in the TRM.
- Create descriptions of the network topologies, equipment, and networking conventions. These will add detail to the items identified in the Integrated Technology descriptions.
- Create reference implementations to reduce design risk when needed, such as the ability to satisfy the properties indicated by the Establish Agency Systems Properties activities. The reference implementations may help remove ambiguity in the definitions, and provide the basis for generating functional tests for implementations. The reference implementation may not exhibit all the properties of a robust implementation.
- Compile, review, and publish drafts and final versions of each description. Formal technical reviews, such as peer reviews ( CMU SEI 1995), can be used to review the descriptions. The individual descriptions should be placed under a version control process to track changes. The descriptions should be reviewed in context of the other parts of the A-TARS, most notably the Integrated Technology, Technology Boundaries, and Platform, Equipment, and Solutions Reference Set descriptions. In particular, the technical limitations of the networking should be addressed, such as maximum throughput.
Update Network Descriptions. Over time, the networking descriptions will undoubtedly change due to changes in the business needs and associated applications, user expectations, emerging technologies ( IPv6), and retirement of legacy protocols and systems. Changes can affect any portion of the OSI stack ( ISO/IEC 1994. Changes to the description must be evaluated, dependencies between definitions made, and changes synchronized.

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Roles and Responsibilities

The key roles and their responsibilities are as follows:

Networking Specialists. These individuals are responsible for producing the network design descriptions, either as authors or technical managers. They are members of the Core or Extended Technical Architecture Team. They are knowledgeable in the areas that the networking design addresses.
Other Technical Specialists. These individuals support the definition of networking, either as authors or Subject Matter Experts, or produce reference implementations and prototypes. These specialties may be obtained from within the IT Division or external (consultants), as needed.

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Artifacts

The following information is used or produced by these activities. Templates, examples, and checklists for identifying and documenting items are available through the Additional Resources section at the end of this page.

A-TARS. The previous version of the A-TARS (if it exists) is used to determine the scope of the changes for an iteration of these activities. The following key parts are used:
- Integrated Technology Descriptions. These descriptions provide the context for the networking descriptions, showing the processing elements, the applications services they should provide, and their connectivity.
- Technology Boundaries Descriptions. The descriptions of the external platforms and the usage environment guide the decisions about networking capabilities available (e.g., dial-up networking, DSL, cable modem), the needs of the types of applications expected to be executed (e.g., video), and environmental concerns (e.g., security).
- Platform, Equipment, and Solutions Reference Set. The capability and cost of platforms and equipment to support the networking design serve as constraints. Requirements for new, modified, or retired capabilities necessary to support the network design are represented as changes that will be used to adjust the descriptions in the Platform, Equipment, and Solutions Reference Set.
- Agency-wide System Properties. These properties are used to guide the networking design, such as performance, security, or scalability.
- TRM Description. This description guides the identification of the network technology required, particularly at the application level.
- Networking Reference Set. These descriptions are the main product of these activities, updating the previous version, if it exists.
AIS Design and Implementation Info. An understanding of the existing technology is used when defining networking, especially if the legacy systems will be retained in the next version of the A-TARS. This provides a ready source of detailed design information, such as existing networking equipment and protocols.
Ancillary Design Information. Information associated with the design is retained, as needed, such as results of architectural studies. This information may be used to produce guidelines that users of the descriptions can reference for additional understanding.
Technical Architecture Work Plans and Direction. These work plans guide the execution of these activities, coordinating the individuals performing these activities with other technical architecture tasks and the IT projects.
Strategic Analysis and Data. The strategic direction, specifically the decisions to keep, replace, renovate, or build on existing IT assets, guides the choice of technology and the integration of legacy system applications into the overall technical architecture.
Changes. Changes provided to these activities represent those things in the current A-TARS descriptions that must change. Changes for other parts of the A-TARS also can be generated, such as updates to the TRM, boundary, integrated descriptions, services, data stores, or equipment.
Status. Progress and issues in developing the descriptions are forwarded to the managment activities to ensure coordination between these activities and other technical architecture and IT project activities.

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Additional Resources

Items that can be used to perform these and other activities are consolidated in the Resources page portion of the IT Planning and Management Guides. Resources specific to this activity are cataloged below.

Consolidated Guidance: Describing the Network Design
Guidance for organizing and describing the network descriptions. 9-18-01

Consolidated Guidance: Technical Reference Models
Guidance for developing descriptions for a TRM, including sources for examples and a sample top-level TRM organization. 7-30-01

Consolidated Information: Standards Organizations
A list of some organizations that promote or verify IT-related standards. 7-30-01

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