14.4 Network-Specific Tools

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For every type of network, there are tools tailored to design them. Some of these tools are fairly easy to use, even for those without formal training in network design. Others are quite complex, intended for use by enterprise users and service providers.

14.4.1 Designing IP Nets

Cisco offers a free tool called ConfigMaker, a Windows-based tool used to configure small IP networks of Cisco routers, switches, hubs, and other network devices from a single PC without requiring knowledge of Cisco operating system software. ConfigMaker is designed for network administrators of small to medium-size businesses who are proficient in LAN and WAN fundamentals and basic network design.

With this tool, the user can address and configure one or more devices or create an entire network of devices in a two-step process that entails creating a network diagram and delivering the configuration file. While the user creates a network diagram, ConfigMaker automatically creates configuration files for Cisco routers, switches, and hubs. The device and connection wizards prompt the user for information about the devices and connections on the network and then use that information to create the configuration files for the devices.

For example, when modular devices are added, the tool prompts the user to enter network modules, WAN interface cards, and voice interface cards so that the software reflects the same hardware configuration as the device. A connection wizard steps the user through the configuration of network links, such as ISDN, and to assign an IP address to the interface.

When connections are drawn between devices, a customized connection wizard helps the user set connection parameters. The configuration files can be viewed, saved, or printed. The user can also save a bitmap image of the network diagram.

For existing networks, an auto-detect wizard facilitates device population of the network diagram by reading any existing configuration to identify the device model and any installed network interface cards.

Another wizard helps the user define VPN connections on the network using the IPsec protocol. ConfigMaker configures the IPsec encryption technology, which allows the creation of site-to-site VPN connections. Internet key exchange (IKE) is used to authenticate each peer in an IPsec transaction, negotiate security policy, and handle the exchange of session keys.

There is also a wizard to help the user define a firewall between the corporate network and its connection to the Internet. The security wizard configures the Cisco operating system’s firewall feature set for an Internet or corporate network connection on the router. The user is prompted to define policies between devices or networks. Users may define broad policies, such as denying or permitting network traffic to pass, or very specific policies for types of allowable traffic.

The NAT feature is used to define static or extended static translations to devices on the corporate network. ConfigMaker configures NAT for additional security and network address conservation/simplification in remote access environments. NAT enables private IP nets that use non-registered IP addresses to connect to the Internet. NAT operates on a router, usually connecting two networks, and translates the private (not globally unique) addresses in the internal network into legal addresses before packets are forwarded onto another network. As part of this functionality, NAT can be configured to advertise only one address for the entire network to the outside world. This provides additional security, effectively hiding the entire internal network from the world behind that address.

ConfigMaker can also be used to set a QoS by limiting bandwidth available for different traffic types. Specifically, the tool configures the committed access rate (CAR), which performs two QoS functions. One function is bandwidth management through rate limiting, which allows the user to control the maximum rate for traffic transmitted or received on an interface. CAR is often configured on interfaces at the edge of a network to limit traffic into or out of the network. Traffic that falls within the rate parameters is transmitted, while packets that exceed the acceptable amount of traffic are dropped or transmitted with a different priority.

The other QoS function is packet classification through IP precedence. This function allows the user to partition the network into multiple priority levels or classes of service (CoS). CAR can be used to set the IP precedence for packets entering the network. Devices within the network can then use the adjusted IP precedence to determine how the traffic is treated.

After creating, addressing, and securing the network, the user can deliver configurations to the devices by using a computer’s communications (COM) port or network connection. Network delivery requires the target device to have an existing IP address assigned to it. The delivery wizard graphically displays the progress of configuration delivery until it is successfully completed.

14.4.2 Designing Wireless Nets

Wireless networks are becoming popular and, of course, there are tools available to help planners and engineers develop wireless network and service plans, including detailed technical and business analyses. One vendor, RSoft Design Group, offers Wireless SWAT, a design tool for service providers and enterprise users that performs complex interrelated traffic, capacity, propagation, equipment, and operations calculations, taking into consideration such factors as potential service areas, service types, and technology types and characteristics, including the impact of multiple simultaneous services, such as voice, data, e-mail, Internet, and video.

The tool can handle a variety of analyses, such as wireless evolution from 1G through 4G, as well as wireless local area networks (WLAN) (e.g., Wi-Fi), multi-channel multipoint distribution service (MMDS), and local multipoint distribution service (LMDS). A key feature of Wireless SWAT is that it designs and grows the plan over multiple periods, either quarterly or annually. As a plan is developed, the user can then analyze the results to determine in which areas, parts of the network, or time periods adjustment is required. For example, if the user wants to vary controls for bit rate and traffic of a proposed service or mixture of services Wireless-SWAT can help the user determine the network sizing and cost of each choice.

The tool can help identify the most cost-effective way of serving an area, considering a multitude of wired and wireless technologies, including detailed telecommunications, capacity, coverage, and economic design. Of special interest to established wireless service providers, as well as ISPs and entrepreneurs who want to set up Wi-Fi networks using the unlicensed 2.4-GHz frequency band, is that Wireless SWAT is capable of processing up to 50 areas in a run, typically less than 15 seconds per study area, and providing reports covering a variety of key elements, such as discounted cash flow, capital/expense flow, and network loads.

Another feature of the tool is its usefulness even when some necessary data for a study is missing. Estimates for the unknown variables can be used instead and, by changing some control screens in a few runs, the user can easily do parametric studies to see which range will be cost-effective. Using this type of technique, a number of key questions can be addressed, such as the following:

• How well does the solution scale with increasing (or decreasing) traffic or market share?

• How economical does the neighborhood hub or access link have to be to still make money?

• How much do I have to charge to make the plan cost-effective?

• Where are the cost bottlenecks or capacity bottlenecks?

• Is technology A more cost-effective than technology B?

• What are the likely economics of my competitors?

By making it easy to answer these types of questions, Wireless SWAT helps the user develop the best network plan. The studies also provide demand-and-service modeling, allowing up to seven simultaneous customer segments, with more than 40 simultaneous services. The study results reflect the combined traffic loads and revenue streams. The tool also has extensible network modeling, enabling the user to input detailed network link and node data or, where the details are not yet available, input limited parameters.

Another feature of the design tool is the guidance it provides when the user inputs the parameters. Validation logic checks user inputs at study setup time to try to prevent incomplete or incompatible inputs. In addition, just before run time, another check is made to detect service, technology, and other incompatibilities. The tool’s pop-up boxes provide appropriate messages, such as valid field ranges or location of errors, so that the study can run effectively.

Another key feature of the design tool is storage of study data. Whenever a study is saved, all of the inputs are stored for reuse so that they do not have to be entered each time a new variation of the plan is tested. The user can open a previously saved study, change desired parameters, services, technologies, or areas and then run and save the study under a different name. In addition to storing a database of studies, the design tool comes with sample catalogs of areas, services, and technology that can be modified with elements added, deleted, and changed through catalog screens. Information in the catalogs, as well as information stored in the database, automatically populates certain fields during design sessions. To save time, most of the screens contain default data or have pull-down menus, allowing the user to choose among a list of selections instead of having to input raw data.

The Wireless SWAT design tool produces numerous graphical reports showing such information as overall and detailed cost-and-load results. Using one of the network element capital/expense flow reports, for example, the user can further examine the plan to analyze which parts of the network are causing the problem. Such reports can be used to evaluate not only the cost-effectiveness of a proposed network but also to compare between two or more plans. For example, a service provider may need to determine whether to include 2.5G in its evolution plans to 3G, along with what factors influence that decision, the dominant critical costs, and the sensitivity to market share rise and falls.

RSoft Design Group also offers a design tool for companies that want to conduct wireline studies for xDSL, cable, direct fiber access, or a combination of wireless and wireline studies. In such cases, they would use Broadband SWAT, which combines all of the capabilities of Wireless SWAT with additional capabilities aimed at supporting wireline studies. For example, a user may need to determine whether DSL or fixed wireless is a better choice for a particular area. Is DSL or fixed wireless a more cost-effective way to reach the customers and, if so, why? Other questions this design tool can answer include the following:

• What are the dominant critical costs?

• How much do the losing technologies’ plug-in costs have to come down for it to win?

• What is the sensitivity to market share dropping 10%?

• How well does the favored choice scale go up if penetration increases 20% in the third year?

14.4.3 Predicting Network Performance

It is not good enough to have tools that lay out and document the network; there must be a way to predict the results to ensure that money is not wasted in trial-and-error implementations. Certain predictive analysis tools offer timely performance information so IT professionals can make the most intelligent decisions about the future of their enterprise resources under different application and traffic load scenarios.

One vendor, Compuware, offers a suite of performance management tools called EcoSYSTEMS, which includes EcoSCOPE, EcoTOOLS, and EcoPREDICTOR. Together, these tools manage and monitor application performance and service levels across the enterprise, helping IT professionals move from preproduction to postproduction and e-commerce environments, as their infrastructure needs change and grow.

EcoPREDICTOR assures service-level conformance by accounting, in advance, for fluctuations in daily or seasonal network traffic. Planners can vary growth-rate scenarios to examine the effects on network traffic and performance. The tool minimizes risk and boosts performance for complex e-commerce and traditional business applications, enabling network managers and software developers to see the effects of launching new applications with existing network traffic on their infrastructure and helping them minimize response times before deployment. The tool also helps network managers use existing information to build models of their infrastructure, so they can determine the effects of traffic and topology changes before they happen.

With the predictor tool, network professionals can overlay VoIP, e-commerce, enterprise resource planning (ERP), customer relationship management (CRM), e-mail, and other application transactions onto live background traffic to see how the application will deploy over the network. Users can then pinpoint alternatives to minimizing response times—such as increasing bandwidth, relocating servers, or increasing processor speeds—and viewing the effect of making each change before it is actually implemented.

More intelligent application decisions based on information learned from analyzing the impacts of changes before they actually occur ensures stable performance levels, particularly for e-commerce, which requires adequate network resources and appropriate capacity planning. Forecasting changes in specific SNA, IP, and streaming helps avert costly service disruptions resulting from a mismatch of resources to demands. Details from EcoPREDICTOR can pinpoint resources such as links, routers, or switches that might be involved in the type of outages that can make or break an e-business.

IT professionals can also import information from EcoSCOPE automatically, enabling them to focus on predicting performance versus the setup requirements often associated with capacity planning. EcoSCOPE provides a network view of application performance by focusing exclusively on Web traffic (HTTP and HTTPS) and drilling down to the Web-page level to provide a granular view of the pages and servers that make up Web traffic. The tool collects detailed performance data on Web applications, such as URL traffic volume and response times for Web applications. This Web focus allows users to analyze how specific pages and their elements affect, and are affected by, the network. Users can track and troubleshoot what, when, how, and where visitors are spending their time and which Web-page elements create unnecessary traffic.

EcoSCOPE also collects Web server statistics, such as page hits, from the Eco-TOOLS server monitoring solution. EcoTOOLS correlates and displays this information with detailed Web traffic data in a single user interface. Together, these products provide an integrated view of Web application traffic and response times with Web server information. This integration enables IT departments to track and correlate Web server load with application performance and gives a better understanding of pages customers access the most. These products also help isolate performance problems, determining if the bottleneck is at the network or server and pinpointing latency to a particular Web server.

A Web-based reporting console provides a common front end for all EcoSYSTEMS historical trending and service-level management reports. It collects data from the EcoSYSTEMS’ historical database and correlates the information into a single set of reports. This database is a common repository for historical data across the EcoSYSTEMS suite and provides multiple views within the infrastructure.

The console also provides IT departments with a single, integrated view of application performance over time. The console facilitates troubleshooting of complex problems and improves communication between IT department staff by giving them a common set of reports they can use to monitor and maintain all elements that impact an application’s performance.

The EcoSYSTEMS platform also offers historical trending reports that track e-business and performance trends and usage of e-business applications, Web servers, and Web sites over time. These reports help anticipate fluctuations and highlight performance problems. The e-business reports also track CPU utilization, traffic volume, and response time by Web servers and top pages for a Web server. The e-business reports gather both network and server Web-related data by accessing EcoSCOPE traffic and response-time metrics and EcoTOOLS Web server data available through the EcoSYSTEMS historical database.

Forecasting reports use EcoPREDICTOR’s predictive capabilities and trend data from the EcoSYSTEMS database to forecast future service levels based on past performance. EcoPREDICTOR analyzes daily and weekly data to project if traffic volume, response time, CPU utilization, and Web server hits will remain steady or increase over time. This is more reflective of future performance than simple linear trending because it accounts for actual past data and normalizes any anomalies in the data such as unusually heavy or light days. E-business trending and forecasting reports are available in the Web-based reporting console.

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