This section discusses the International Organization for Standardization (ISO) network management model, called FCAPS, which represents the following:
- Fault management
- Configuration management
- Accounting management
- Performance management
- Security management
Fault Management
The first functional area of the FCAPS model is fault management. This area deals with error conditions that can cause administrators and users to lose functionality, resulting in not being able to use certain network resources. This is a key area for network management.
Fault management activities include finding abnormal network operations, and isolating and correcting the faults that occur. This is accomplished in the following five steps:
- Detect the problem.
- Diagnose the fault.
- Bypass and recover.
- Resolve the situation.
- Track and manage the problem.
The two main components of fault management (Figure 2.14) are as follows:
- The event generators (devices that generate the events, such as routers, switches, access servers, hosts, etc.)
- Event collectors (devices that receive SNMP/Syslog messages from the event generators); event collectors, also called event management systems (EMSs), can be third-party servers or CiscoWorks machines
Figure 2.14 – Fault Management
The events sent from the event generators to the event collectors can be one of the following:
- State events, sent when a network device changes its state (a link goes down due to a configuration change, changes in the routing protocols, etc.)
- Performance events (disk space usage, link errors thresholds, high CPU utilization, etc.).
Once the event generator produces events, they are collected and processed by the EMS (CiscoWorks). This follows a five-step process outlined below:
- Event collection
- Event normalization (normalizing Syslog events based on their timestamps)
- Event filtering (ignoring low priority events)
- Event correlation
- Event reporting (in a text or GUI format)
Configuration Management
The configuration management area of FCAPS is the process of collecting different information on the network, driving consistency throughout all the network devices, tracking changes in the network, and ensuring network documentation is up to date (e.g., from Cisco.com or other standardization organizations), using the most recent versions.
The configuration management process also includes tracking and storing software versioning of all the network devices, and making sure the most recently updated IOS and the most recent software builds are used for all of the systems. It also allows the availability of improving all the devices, with the overall goal of configuration management to lower the time and cost overhead. For example, by building an efficient configuration management system within CiscoWorks, you can lower the TCO of the network infrastructure because fewer administrators will be required to work on those specific tasks.
Configuration management includes activities such as documentation, configuring control settings in the Cisco IOS, object mapping (ensuring objects are properly managed and associated), overall data collection for configuration information (configuration files on a server that can be downloaded via TFTP) and change configuration, and ensuring the TCO is lowered by being able to track all the network devices’ configuration changes. These activities are then stored in a database or presented in a GUI format within CiscoWorks.
CiscoWorks ensures that the organization complies with the newest standards by keeping up with the software versioning and updates, ensuring standard IP addressing and naming convention (DNS) schemes are used, and ensuring that an efficient DHCP process is in place. In addition, by using CiscoWorks, you can ensure that the organization uses standard configurations that are compatible with other companies and that configuration upgrades are in place. Moreover, a step-by-step procedure should exist for making configuration changes on the network devices. This can be accomplished using CiscoWorks templates to make the process easier.
Accounting Management
The accounting management area usually uses AAA services. There are a few different approaches regarding accounting management, for example, intra-organization management or inter-organization management.
If the AAA services are implemented within the company, you need to make sure people are who they claim to be when they try to access an object or do something on a device. Then you must authorize what they can do with those objects or devices. After that, you must account for what activities they engage in, sometimes for billing purposes.
Account management helps manage resources between the individuals in the company, security groups, different departments, and business entities to track expenditures, for example, or for security auditing. It can also be used for helping departments stick to their budgets and ensuring that everyone has enough resources for their types of networking activities (e.g., IP Telephony, multimedia applications, or video-conferencing). The overall goal of accounting is to measure and regulate network utilization. As mentioned, the accounting process will have a different purpose when used inside the company than when used between companies (e.g., an ISP scenario).
An ISP would use the accounting management aspect to offer flexible billing plans to their customers and to track the usage of network resources on a customer-by-customer basis. This allows network administrators to retrieve, display, and create bills for their customers.
IP accounting is based on the source or destination IP addresses, or on the IP precedence value in the IP header, when using QoS technologies in order to attain granularity. Other aspects of IP accounting include the data type, the number or size of the packets, MAC addresses, and violations to access control list settings using event logging.
The accounting management process is typically carried out with a RADIUS or TACACS+ server, especially for the authentication and authorization parts. The NetFlow solution mentioned earlier also provides powerful accounting services with its NetFlow collector, accounting, and billing applications.
An example of using the accounting management solution would be within a VPN remote access module on the enterprise edge to account for and to audit the company dial-up connections and the sessions on the WAN and ISDN links.
Performance Management
The performance management area is usually managed by a system administrator or by a network administrator/engineer. Nevertheless, the network designer should ensure that the organization has performance management techniques in place so that overall management guidelines are followed.
The goal of performance management is to keep the network uncongested 24/7, with all the devices accessible. Another goal is to reduce overhead and downtime (a recommended target to achieve is 99.9% network uptime). An important part of performance management is to provide service-level management (SLM) or service-level agreements (SLAs) established with the customers. This is a proven methodology to ensure that you can deliver the promised services to the organization, to individual departments, to business services, and to customers (in the case of ISPs).
Part of performance management is to identify trends in network operations, such as the usage of bandwidth, application usage, and other support services and intelligent services, as well as performing a “what-if” analysis. This means finding the optimal level of operations for the company. Another step in this process is creating baselines of activity within the organization with the help of system engineers, as a point of reference in order to analyze deviations from normal network behavior (e.g., peak activity for bandwidth and applications). This aspect is related to a concept called exception management, which creates a baseline of activity (thresholds of normal activity) and figures out when exceptions (violations of the thresholds) will occur and what those exceptions will be (e.g., peak CPU utilization or exhaustion of other resources).
Performance management also includes QoS management. This is important, especially for an ISP that offers solutions such as IP Telephony, multicasting, or video-conferencing. The implemented QoS techniques should be managed, including the way packets are prioritized as they travel through the network. This includes concepts such as Committed Access Rate (CAR) or Class Based Weighted Fair Queuing (CBWFQ), using queuing mechanisms to achieve QoS.
When a violation in performance is detected, the network staff must be able to fix that particular issue as quickly as possible and with little impact on the users in the organization.
Security Management
The last area of FCAPS is security management. The goal of security management is to ensure that you have access control to network resources, and you can prevent intentional or accidental changes to a particular object or device and unauthorized access to sensitive corporate information.
Some of the protocols and tools that can be used within security management on the routers, switches, and other devices include the following:
- Telnet and SSH for connecting to the devices (SSH is preferred due to its encryption abilities)
- SNMP for management and monitoring of the device parameters (SNMPv3 is preferred due to its authentication and privacy features)
- HTTP and HTTPS for web access to the device
- RADIUS and TACACS+ for authentication and authorization
- AAA
More information about assessing the security within the network design will be presented in Chapter 8.