Managing Network Design

Managing Network Design

•	The Right Way:
•	keep in mind the business opportunities and platform requirements
•	high level analysis of client preferences and technical trade-offs
•	detailed translation of strategic requirements into technical specifications
•	specifications to implementer for final design and execution
•	The Wrong Way:
•	nobody is acting as designer
•	management tells implementer to:
•	supply connectivity
•	minimize costs
•	business goals are never stated
•	business platform not considered
•	result:
•	NETWORK FROM HELL!!!

Key Design Variables

•	Capability -- the range and volume of services handled by the network
•	Flexibility -- the ease and speed with which changes can be made
•	Quality of service -- how well the network meets the needs of customers
•	Cost -- the ultimate trade-off factor

Capability

•	Range of services must support the strategic business goals of the company
•	Be aware of new technology that will support new business opportunities
•	Integrate only if necessary -- cheaper and easier to supply specific services
•	Forecast capacity -- capacity is expensive -- and having it often creates its own demand

Flexibility

•	Common solution for today’s WANs: use public networks with SDNs and VPNs
•	For LANs: use open architectures for rapid network modifications
•	Beware:  the most flexible architectures have the highest costs and fixed overhead

Quality of Service

•	Customer requirements dictate level of:
•	capability and flexibility, as well as:
•	reliability -- error-free continuity of service
•	responsiveness -- how fast the customer’s message is processed and answered
•	accessibility -- how simple and convenient it is for the customer to access your network
•	network security -- there are clear trade-offs between convenience and security

Costs

•	Three main categories of costs:
•	Variable -- costs increase with volume, as in your long distance bill
•	Step-shift -- variable costs up to a limit of capacity, then additional investment
•	Fixed -- cost is the same regardless of volume.  For instance:  a LAN, or a file server, or a leased line.  All costs are constant regardless of use

Trade-offs Among Design Variables

•	The essence of the designer’s role is to effectively manage trade-offs to obtain acceptable service at acceptable cost.
•	There is no “optimal” network design -- that’s why the same company may have many different networks
•	The cost range of comparable networks may vary considerably due to management skills, economies of scale, technical and operational efficiency, but are mainly the result of design trade-offs.

Policy Issues Influencing Design Choices

•	The degree and pace of change acceptable to management
•	Choice of vendors
•	Telecommunications platform architecture and range of services
•	The planning horizon
•	The level of risk considered acceptable

Degree of Change

•	Link the pace of technical change to organizational change -- competitive pressures vs. cultural constraints
•	This means education about the company’s strategic goals
•	Education to support a change in policy must begin early and be pervasive -- the concept of the “learning organization”

Choice of Vendors

•	Very important because of a lack of widely accepted standards
•	Vendors can provide invaluable help in design and implementation
•	One option: one primary vendor for both telecommunications and computing, or
•	One vendor for telecommunications and one for computing
•	However, there are strong arguments against using a single primary vendor, primarily because of LANs
•	Another however:  defining criteria using multiple vendors is very difficult
•	Any multivendor plan must be built around standards of compatibility
•	Other key criteria:  service and support
•	The main issue:  ensure consistency

Telecommunications Platform Architecture

•	Specific architectures are determined more by vendors than standards
•	Even OSI and ISDN standards have many different incarnations
•	The main questions:
•	Do we commit to a single architecture?
•	How to integrate with the current system?
•	Different architectures for different applications or business units?
•	Different architectures for different
•	applications or business units?
•	What range of services should be anticipated in the architecture?

The Planning Horizon

•	CEOs want network innovation for increased competitiveness, but want a rapid cost recovery on the investment
•	3 to 5 year intermediate innovation and 5 -10 year long-term recommendations may be too long
•	Investment payback and bottom-line results are demanded over a much shorter period

Level of Risk

•	Technological Risk -- cutting edge vs. conventional and proven technology?
•	Financial Risk -- can costs be limited to the approximate original budget?
•	Organizational Risk -- can we handle the changes in corporate culture?
•	Business Risk -- will the customers like it and will it be profitable?

Total Quality Management

•	A holistic, systems view of the organization
•	A continuous process-improvement focus
•	Management by fact
•	Obsession with customer satisfaction
•	Respect for people and commitment to employee development and fulfillment