IBM Tivoli and Cisco manual Implementation flow, Scalability and high availability

revalidation process takes place too often, this pop-up window may become annoying and significantly lower the user’s productivity. The recommended value is 14400 seconds (4 hours) or more.

The router or the network access device (NAD) periodically queries the client for the current policy compliance status changes. This activity introduces additional network traffic, which becomes larger as the defined time intervals shorten.

However, frequent polling enables quick disconnection from a client that becomes noncompliant from the network. Depending on the network architecture (number of clients connected to one NAD, network bandwidth, current network load, and so on) the status query period should not be shorter than 30 seconds.

2.4 Implementation flow

IBM best practice in implementation of this concept in an enterprise-wide deployment has been identified by the following project phases that would assist in a smooth transition to the new environment:

￿Initiation

￿Definition

￿Design

￿Build

￿Maintenance

In the initiation phase, high-level project requirements are gathered and verified to be included in the Statement of Work (SoW) document.

During the definition phase, those requirements are refined and documented in detail, and as a result several of the documents are created, including Project Definition Report (PDR), functional specification, and existing system analysis.

In the design phase, the detailed design of the solution is created, typically in the

form of architecture and design documents covering macro and micro design studies. Then the solution is actually implemented in the build phase.

The final stage is maintaining and updating the solution as the surrounding environment or business requirements change. This typically is a cyclic process as described in 2.3.2, “Security policy life cycle management” on page 30.

2.5 Scalability and high availability

Any architecture must be easily scalable and available at all times for secure and reliable business transactions and the future growth of the business. This

Chapter 2. Architecting the solution 35