Exam Essentials


Understand Cisco’s Small- to Medium-Sized Business Solutions Framework. Cisco’s solutions framework categorizes most problems into one of three areas. Media problems are identified as high rates of utilization and can be addressed with separate collision domains. Protocol problems can be attributed to broadcasts and can be addressed with separate broadcast domains. Transport problems can be similar to small freeways, and the need for larger amounts of bandwidth is justified.

Understand how to gather information about the current network. In order to determine the proper network setup, you must first consider the existing network. Administrative data helps you understand the workings of the company, and the potential business constraints are nontechnical items that will affect your final network design. Technical data helps you understand the customer’s expectations and can be gathered with protocol analyzers and network management stations.

Know how to map the current network. Mapping existing applications, network protocols, network topologies, addressing maps, and current bottlenecks will help you understand the customer’s needs and give you a complete picture. It will also help you understand current and future design challenges and current bottlenecks that will help you identify the three network traffic types, the source and destination, and local and non-local segment traffic.

Understand business constraints and network availability, performance, reliability, and utilization. Business constraints include the nontechnical administrative data and political factors. Network availability, performance, reliability, and utilization will help you to identify network down time, latency, up time with possible errors, and percent of network usage.

Be able to use existing routers and network management systems to gather information for a successful network design. The overall health, CPU, and memory utilization of existing network routers will be important information later in the design process for the consideration of network protocols and routing equipment. Existing network management systems and the data they provide will help you understand the customer’s current system and the customer’s expectations.

Know the overall health of the customer’s network. You need to be able to determine the limitations of the existing network. Ethernet segments should not exceed 40 percent utilization or exhibit more than one CRC error per one million bytes of data on any network segment. Token Ring segments and WAN links should not exceed 70 percent utilization. Network response time should be less than 1/10 of a second (100 milliseconds). Broadcasts/multicasts should not be more than 20 percent of the overall network traffic. No router CPU utilization should exceed 75 percent.

Know how to evaluate the needs and expectations of the customer. Business constraints can be a major factor in a successful network design. Buy-in from the customer’s staff, users, and management is crucial for any designer. Security, manageability, application, and performance requirements most often will require a give-and-take process between the customer and the network designer. A network design and the customer’s expectations will need to meet on middle ground.




CCDA. Cisco Certified Design Associate Study Guide
CCDA: Cisco Certified Design Associate Study Guide, 2nd Edition (640-861)
ISBN: 0782142001
EAN: 2147483647
Year: 2002
Pages: 201

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