Flashcards in Chapter 11 Test 2 Deck (54):
What two tasks do network managers perform?
-designing new networks and network upgrades.
-managing the day to day operation of existing netowrks.
Describe the traditional network design process.
-very structured systems analysis and design process similar to that used to build application systems.
Describe steps of the traditional network design process.
-identify user needs and application systems.
-precise estimate of the amount of data that each user will send and receive and estimate total traffic on each part of the network.
-design circuits to support traffic plus modest increase in traffic and cost estimates are obtained from vendors
-network is built and implemented.
What is the most expensive part of the network today?
-the staff members who design, operate and maintain it.
Describe the building-block process to network design.
-networks use a few standard components throughout the network are cheaper in the long run than networks that use a variety of different components on different parts of the network.
What are advantages of the building-block process?
-simpler design process and a more easily managed network built with a smaller range of components.
Describe the three steps of the building block process.
Describe needs analysis
-designer attempts to understand the fundamental current and future network needs of the various users departments and applications.
Describe the technology design step.
-examins available technologies and assesses which options will meet users' needs.
Describe the cost assessment step.
-relative costs of the technologies are considered
-process then cycles back to needs analysis.
What are the objectives of the needs analysis stage?
-identify the geographic scope of the network and users and applications that will use it.
Describe access layer.
-technology that is closest to the user
-the user's first contact with the network.
Describe the distribution layer.
-part of network that connects the access layer to the rest of the networks.
Describe the core layer.
-innermost part of the network that connects the different distribution layer networks to each other.
-busiest most important part of the network.
What considerations in regards to applications must you take when designing a network
-applications that will use network and future applications that are expected to use the network.
What applications are most likely to be high traffic?
-those that load executables over the network, large amounts of multimedia or need constant updates(financial, order processing)
What categories should network requirements be divided into?
-mandatory requirements, desirable requirements, and wish-list requirements.
What is the deliverable of the needs assessments stage?
-set of logical network diagrams showing the applications, circuits, clients and servers in the proposed network each categorized as either typical or high traffic.
-logical diagram is conceptual.
Describe a physical network design.
-starts with the client and server computers needed to support the users and applications.
-circuits and devices connecting them are designed.
What are the two interrelated decisions in designing network circuits and devices?
-fundamental technology and protocols.
-capacity of each circuit.
Describe capacity planning.
-estimating the size and type of the standard and advanced network circuits for each type of network(LAN, BN, WAN).
Describe circuit loading.
-amount of data transmitted in a circuit.
What should you design for?
-peak circuit traffic.
-total characters transmitted per day on each circuit.
-max characters transmitted per two-second interval if peaks must be met.
Describe the turnpike effect.
-traffic increases much faster than originally forecasted.
-mathematical technique in which the network comes to life and behaves as it would under real conditions.
-used to model the behavior of the communications network.
Describe Cost assessment.
-assess the costs of various physical network design alternatives produced in the needs analysis.
What are the main items of the cost assessment.
-costs of software
-costs of hardware
-costs of circuits.
-request for proposal.
-sepcify what equipment, software and services are desired and ask vendors to provide their best prices.
What are the deliverables of the cost assessment stage?
-RFP that goest to potential vendors
-revised physical network diagram(after vendor has been selected).
-business case that provides support for the network design, expressed in business objectives.
Describe managed devices.
-standard devices such as switches and routers that have small onboard computers to monitor traffic flows through the device as well as the status of the device and other devices connected to it.
Describe device management software.
-point management software.
-provides info about specific devices on a network
-enables network-manager to monitor important devices such as servers, routers and gateways.
Describe system management software.
-enterprise management software
-provides samem configuration, traffic, and error information as device management systems, but can analyze the device information to diagnose patterns, not just display individual devie problems.
What is an alarm storm?
-when one failure generates several dozen problem reports.
What is root cause analysis?
-correlate the individual error messages into a pattern to find the true cause.
Describe application management software.
What are the two most commonly network management protocols?
-Simple Network Management Protocol(SNMP)
-Common Management Interface Protocol(CMIP)
-Internet network management standard
-developed to control and monitor status of TCP/IP networks..
-newer protocol for OSI-type networks developed by the ISO
How does SNMP work?
-Each device has an agent that collects information about itself and stores in a central database called the management information base(MIB).
-a network management software runs on the network manager's station.
-ability for remote monitoring(RMON).
Describe policy-based management.
-network manager uses special software to set priority policies for network traffic that take effect when the network becomes busy.
Describe traffic analysis.
-pinpoints why some circuits are heavily used.
-specifies exact type of performance teh common carrier will provide and penalties if the performance is not provided.
-delay imposed by the device in processing messages.
Describe wire speed.
-operate as fast as the circuits they connect and add virtually no delays.
Describe device memory.
-if device does not operate at wire speed must have sufficient memory to store the packets.
Describe load balancing.
-forward requests to a server that is not busy or is the least busy.
Describe a load-balancing switch.
-acts as a router at the front of the server farm.
-all requests directed to its ip address.
-it then forwards request to specific server.
Describe server virtualization.
-process of creating several logically separate servers.
-runs on same physical computer, but appear completely separate to the network.
Describe capacity management devices.
-bandwidth limiters or bandwidth shapers.
-monitor traffic and can act to slow down traffic from users who consume too much capacity.
-allocate capcity based on the ip address of the source as well as the application in use.
Describe content caching.
-store other people's web data closer to your users.
Describe content engine.
-installed close to your internet connection and content management software on the router.
-directs outgoing requests to internet and responses to cache engine.
-stores the request and the static files that are returned in response.
-examines outgoing web requests to see if it already has the content.
Describe content delivery.
-pioneered by Akamai.
-content delivery providers store web files for its clients closer to the potential users.
Describe green IT.
-design and use of information technology to improve environmental sustainability.
-much focuses on reducing amount of power consumed and heat produced.