Service-Oriented Network Architecture

Service-Oriented Network Architecture (SONA) attempts to provide a design framework for a network that can deliver the services and applications businesses need. It acknowledges that the network connects all components of the business and is critical to them. The SONA model integrates network and application functionality cooperatively and enables the network to be smart about how it handles traffic to minimize the footprint of applications.

Figure 1-3 shows how SONA breaks down this functionality into three layers:

• Network Infrastructure: Campus, data center, branch, and so on. Networks and their attached end systems (resources such as servers, clients, and storage.) These can be connected anywhere within the network. The goal is to provide anytime/any place connectivity.

• Interactive Services: Resources allocated to applications, using the network infrastructure. These include:

• Management

• Infrastructure services such as security, mobility, voice, compute, storage, and identity

• Application delivery

• Virtualization of services and network infrastructure

• Applications: Includes business policy and logic. Leverages the interactive services layer to meet business needs. Has two sublayers:

• Application layer, which defines business applications

• Collaboration layer, which defines applications such as unified messaging, conferencing, IP telephony, video, instant messaging, and contact centers

Planning a Network Implementation

It is important to use a structured approach to planning and implementing any network changes or new network components. A comprehensive life-cycle approach lowers the total cost of ownership, increases network availability, increases business agility, and provides faster access to applications and services.

The Prepare, Plan, Design, Implement, Operate, and Optimize (PPDIOO) Lifecycle Approach is one structure that can be used. The components are:

• Prepare: Organizational requirements gathering, high-level architecture, network strategy, business case strategy

• Plan: Network requirements gathering, network examination, gap analysis, project plan

• Design: Comprehensive, detailed design

• Implement: Detailed implementation plan, and implementation following its steps

• Operate: Day-to-day network operation and monitoring

• Optimize: Proactive network management and fault correction

Network engineers at the CCNP level will likely be involved at the implementation and following phases. They can also participate in the design phase. It is important to create a detailed implementation plan that includes test and verification procedures and a rollback plan. Each step in the implementation plan should include a description, a reference to the design document, detailed implementation and verification instructions, detailed rollback instructions, and the estimated time needed for completion. A complex implementation should be done in sections, with testing at each incremental section.