Cisco Cisco IOS Software Release 12.0(1a) 白皮書
response time allowed. You can use this information to validate the solution. Ultimately, this information will
help determine the required and expected performance and availability of the network, and ensure that the
solution is acceptable.
help determine the required and expected performance and availability of the network, and ensure that the
solution is acceptable.
Solution Scalability Objectives
Creating solution scalability objectives helps you design networks that meet future growth requirements and
ensure that proposed designs do not experience resource constraints during expected growth of the network.
Resource constraints include overall traffic volume, number of routes, number of virtual circuits (VCs),
neighbor counts, broadcast domains, device throughput, media capacity, and a number of other
scalability−type parameters. You should determine the required life of the design, expected extensions or sites
required through the life of the design, volume of new users, and expected traffic volume or change.
ensure that proposed designs do not experience resource constraints during expected growth of the network.
Resource constraints include overall traffic volume, number of routes, number of virtual circuits (VCs),
neighbor counts, broadcast domains, device throughput, media capacity, and a number of other
scalability−type parameters. You should determine the required life of the design, expected extensions or sites
required through the life of the design, volume of new users, and expected traffic volume or change.
Availability Objectives
Creating availability objectives to define the level of service helps ensure that the solution meets
end−availability requirements. You can define different classes of service for a particular organization and
detail the appropriate network requirements for each class. Different areas of the network may require
different levels of availability. A higher availability objective may necessitate increased redundancy and
support procedures as well as stable non leading−edge type components. By defining an availability objective
for a particular network service and measuring that availability, you can understand components and
service−level requirements.
end−availability requirements. You can define different classes of service for a particular organization and
detail the appropriate network requirements for each class. Different areas of the network may require
different levels of availability. A higher availability objective may necessitate increased redundancy and
support procedures as well as stable non leading−edge type components. By defining an availability objective
for a particular network service and measuring that availability, you can understand components and
service−level requirements.
Interoperability with Existing Environment
Interoperability and interoperability testing can be critical to the success of new solution deployments.
Interoperability can refer to different hardware vendors or even different topologies or solutions that must
mesh during or following a network implementation. Interoperability problems can include hardware
signaling through the protocol stack to routing, or transport−type problems. Interoperability planning should
include connectivity between different devices and topology issues that might occur during migrations.
Interoperability can refer to different hardware vendors or even different topologies or solutions that must
mesh during or following a network implementation. Interoperability problems can include hardware
signaling through the protocol stack to routing, or transport−type problems. Interoperability planning should
include connectivity between different devices and topology issues that might occur during migrations.
Solution Comparison
We recommend comparing different potential designs in relation to other solution requirement practices. This
helps ensure that the solution is the best fit for a particular environment and that personal bias does not drive
the design process. Factors to compare include cost, resiliency, availability, risk, interoperability,
manageability, scalability, and performance. All of these can have a major effect on overall network
availability once the design is implemented. Comparisons can be done on media, hierarchy, redundancy,
routing protocols, and similar feature capabilities. A chart with factors on the X−axis and potential solutions
on the Y−axis helps summarize solution comparisons. Detailed solution comparisons in a lab environment
also help to objectively investigate new solutions and features in relation to the different comparison factors.
helps ensure that the solution is the best fit for a particular environment and that personal bias does not drive
the design process. Factors to compare include cost, resiliency, availability, risk, interoperability,
manageability, scalability, and performance. All of these can have a major effect on overall network
availability once the design is implemented. Comparisons can be done on media, hierarchy, redundancy,
routing protocols, and similar feature capabilities. A chart with factors on the X−axis and potential solutions
on the Y−axis helps summarize solution comparisons. Detailed solution comparisons in a lab environment
also help to objectively investigate new solutions and features in relation to the different comparison factors.
Documented Network Design
The network design documents should include basic logical network connectivity, ports, addressing,
configuration requirements, distances between devices, and alternatives. You should analyze required
features, performance requirements, availability objectives, manageability objectives, and interoperability in
relation to the design. We recommend documenting the design phase to show how the proposed design model
meets solution requirements. Consider and document alternative models including benefits and issues in
relation to the design requirements. Physical design issues may also be important during the design phase
because of space limitations, distances, chassis capacity, power, or other physical limitations. The physical
design requires space planning, power planning, rack design and layouts, device memory and CPU
requirements, port and card assignments, cabling requirements, carrier requirements, and physical device
configuration requirements, distances between devices, and alternatives. You should analyze required
features, performance requirements, availability objectives, manageability objectives, and interoperability in
relation to the design. We recommend documenting the design phase to show how the proposed design model
meets solution requirements. Consider and document alternative models including benefits and issues in
relation to the design requirements. Physical design issues may also be important during the design phase
because of space limitations, distances, chassis capacity, power, or other physical limitations. The physical
design requires space planning, power planning, rack design and layouts, device memory and CPU
requirements, port and card assignments, cabling requirements, carrier requirements, and physical device