Brief Detour Service Level Relationships Between Layered Communication Services

Services such as voice generally rely on services provided at lower layers, such as datatransmission services. Therefore, there are dependencies between the levels of service that are experienced at different layers. For example, there could be a relationship between the quality of the voice service that is experienced and the link or routing capacity at a lower layer If the capacity is too low, voice packets will be lost and the quality of the voice will suffer. However, to average users, it...

Day in the Life of a Network Manager

Let us consider some typical scenarios people face as they run networks. No single scenario is representative by itself. Scenarios differ widely depending on a number of factors. One factor is the type of organization that runs the network. We refer to this organization as the network provider. The IT department of a small business, for example, runs its network quite differently than the IT department of a global enterprise or, for that matter, a global telecommunications service provider....

Is for Accounting

Organizations that offer communication services over a network ultimately need to generate revenue for the services they provide. After all, this is how they make their living. If they do not bill for the services they provide, they will not stay in business for long notwithstanding some dotcom businesses that might give a service away but compensate for it through some other means, such as advertisements. Even if the organization is not a service provider but, say, an internal IT department...

Management Systems Reason for Being

Unlike the network element, a management system exists only for the purposes of network management. It is not per se required for the network to function. If you have a management system that manages your network, and disaster strikes so that from one moment to the next, the management system stops working, the network itself should be completely unaffected. Ongoing phone calls that run over your network will not be disrupted, and it will even be possible to place new phone calls. Data will...

More Formal Definition

Given the previous examples, this definition sums up a little more formally what's involved in managing a network Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems. Operation deals with keeping the network (and the services that the network provides) up and running smoothly. It includes monitoring the network to spot problems as soon as possible, ideally before a user is...

Simple Modeling Example

Imagine that you are tasked with defining a simple management information model for a device. All you are interested in managing is some basic system information about the device, such as the name of the device, where it is located, who the contact is, how long it has been running, and its TCP connections. The resulting models are graphically depicted in the following figures. All three represent the same underlying domain, but each is based on a different type...

About the Technical Reviewers

Prakash Bettadapur is a Senior Engineering Manager at Cisco Systems. He has been with Cisco since 1999, working in various network management and IOS manageability programs. Before Cisco, Prakash worked in Bell Northern Research (BNR) in Ottawa, Canada, and in Nortel Networks in Santa Clara, California, for 14 years. While in BNR Nortel, Prakash worked in DMS-Service Control Point, Data Packet Networking (DPN), Magellan Passport, and Meridian PBX product lines, focusing on the areas of software...

Accounting for Communication Service Consumption

To track the consumption of network services, meters must be set up that collect usage data. In the case of some services, usage data is automatically generated. For example, in the case of voice, call detail records (CDRs) are automatically generated by the network as part of call setup and teardown. Of course, these records still need to be collected, making sure that none are lost. In addition, because communication services often are provided across a network, duplicates must be eliminated....

Accounting Management as a Service Feature

To simplify accounting and to simplify communication products, in many instances, flat-fee instead of usage-based models are offered. As mentioned earlier, flat-fee Internet service is one example. Of course, although flat fees ease some of the requirements of tracking precise use, other aspects, such as the need to attribute service use to authorized users who are known to the service provider and not delinquent on their bills remain. In addition, accounting management can serve as an...

Acknowledgments

At various stages of writing this book, I had interesting discussions, support, and valuable feedback from many friends and colleagues. In particular, I would like to acknowledge Ron Biell, Steve Chang, Eva Kr ger, Victor Lee, Dave McNamee, Fred Schindler, Hector Trevino, Eshwar Yedavalli, and Ralf Wolter. A very special thank you goes out to my dad, Helmut Clemm, who, in fact, read through the entire manuscript and, although not a network manager, provided many useful insights. I also want to...

Actions

Finally, some interactions cause the device to perform a certain action. Examples are a request for the device to reboot itself, a request to perform a self-test, or a request to ping another device to see if it can be reached. Those interactions are very straightforward A request is sent to perform the action, and a response is sent that indicates the outcome of the action or any errors that were encountered. One special case occurs when performing the action might take some time. This could...

Adapting Integration Approach and Network Provider Organization

One aspect that will likely influence a network provider's approach to management integration is how its operations organization is set up. The larger the network that needs to be managed, the more important it becomes how the organization that is responsible for managing the network is structured. After all, the management organization itself is an important part of how networks are managed hence, integrated management does not stop at the technical infrastructure but needs to take the...

Additional Considerations

A few aspects of the TMN hierarchy shown in Figure 4-5 should be noted. First, different management layers are often handled by different organizations and sometimes even by different service providers. This way, the technical layering can influence how a business is vertically layered and can define the actual business relationships. For example, a transport provider might provide raw transmission services physical lines and transmission equipment. Network service providers provide networked...

Advanced Alarm Management Functions

Beyond those basic alarm management functions, in any network of meaningful size, additional functions to manage alarms are required. Some of those functions provide network managers with greater flexibility in processing alarms. For example, an alarm-forwarding function might send alarms to the pager of an operator to allow for an automatic dispatch, much as a home intrusion detection system automatically calls the local police station. Another function allows network operators to acknowledge...

Agent Initiated Interactions Events and Event Based Management

The second big category of interactions between managers and agents concerns events. Here, the agent initiates communication and sends the manager an event message to bring something to the manager's attention, usually about some type of occurrence or event that has occurred. For example, the event message could be an alarm that indicates that the device is overheating or that it has been experiencing a failure. It could indicate that a new configuration setting has just gone into effect. Or...

Alarm and Event Correlation

Generally, alarm correlation refers to an intelligent filtering and preprocessing function for alarms. Alarm messages are intercepted and analyzed and compared to identify which alarms are likely related. For example, alarms could be related because they report the same symptom or because they probably have the same root cause. Depending on the sophistication of the correlation function, different aspects can be taken into account information contained in the alarms themselves, context...

Analogy 1 Health Carethe Network Your Number One Patient

A network is not unlike a complex living organism. Let us therefore compare a network with a patient who is in an intensive care unit in a hospital. The patient, of course, is under intensive scrutiny, just as your network should be. After all, the network could be the lifeblood of your enterprise. In an intensive care unit, monitoring the patient's pulse is constantly required. A slowing or missing pulse, after all, requires an immediate response. Other health functions of the patient are...

Analogy 2 Throwing a Party

Running a network has much in common with running events. Think for a moment of a network as analogous to a big party not a party you attend as a guest (that is, an end user), but one that you are hosting (that is, managing). Depending on the type of party and the number of guests, throwing a party involves many different activities. Long before the date of the party, planning begins Invitations need to be designed, printed, and sent out. Organizational questions abound. Do you throw it at your...

Anatomy of a MIB

To get a taste of what a MIB looks like in practice, let's take a look at a specific MIB specification language and an actual MIB definition specified in it. Because of the ubiquity of SNMP, we use SNMP's Structure of Management Information (SMI) as our example, and for the MIB definition we take a look at an excerpt of MIB-2. MIB-2 was specified for use with devices that implement the TCP IP protocol stack. It can hence be found on virtually any device that supports SNMP today and, in all...

Application Characteristics

Typically, management systems have to support many different functions. As it turns out, many of those functions really need to be supported through their own (sub)applications. Many of these applications have characteristics with certain architectural implications. We discuss management applications and tools in greater detail in the next chapter. However, let us preview some typical and important types of network management applications to illustrate the wide range of application...

Approaches to Management Integration

The integration problem is generally too large to be tackled all at once. Often there is a trade-off to make Does management infrastructure have to be integrated all the way, thereby making management more efficient but more expensive Or is it acceptable not to integrate certain aspects, to lower management integration complexity and cost, at the expense of operations that might be a little less efficient as a consequence If a decision is made to settle for less than full integration, the...

Auditing Discovery and Autodiscovery

Being able to configure your network is important, but not enough. You need to also be able to query the network to find out what actually has been configured you need a read in addition to the write. This is referred to as auditing. Many reasons exist for auditing devices in the network. For example, you might want to verify that the configuration of the network is indeed what you expect it to be. You might want to see if configuration commands that you sent down indeed took. Without this...

Basic Management Ingredients Revisited

Now that the notion of real resources and the distinction between the network device and the management agent is in place, we can briefly revisit our original picture of the basic management components to include that distinction. Figure 3-6 refines Figure 3-1. At the most basic level, there are really only two components, depicted at the top and at the bottom the network provider's operational support organization and the real world that it wants to manage. However, technical means are...

Benefits of Integrated Management

Having management that is integrated as opposed to management that is based on a piecemeal approach that consists of multiple management islands is important for many reasons that include the following It helps ensure that management tasks do not fall through the cracks. Management tasks that are supported by a holistic, integrated operational support environment do not need to rely as much on manual procedures and leave little to chance, compared to management tasks that are not supported by...

Billing Systems

Last in our list, but not least, are billing systems. We did not discuss billing systems in any of our earlier scenarios, but we should not lose sight of the reason many network providers (service providers, in particular, not enterprise IT departments) are in the business of running networks in the first place to make money. Billing systems are essential to the realization of revenues. They analyze accounting and usage data to identify which communication services were provided to whom at what...

Books on Network Management

Build the Best Data Center Facility for Your Business. Cisco Press, 2005. A how-to guide on setting up and operating a data center, providing insight on how to apply network management in the context of data centers. Claise, B., R. Wolter. Network Management Accounting and Performance Strategies. Cisco Press, 2007. As indicated by its title, this book provides an in-depth look at accounting and performance management. Deveriya, A. Network Administrators Survival Guide. Cisco Press,...

Build Complexity

We first explore the aspect of build complexity that is, the complexity of scaling management application development. Imagine for a moment that you were tasked to build a simple service provisioning application for example, to provision digital subscriber line (DSL) service as explained in Chapter 7, Management Communication Patterns Rules of Conversation. We assume that you have a single type of DSL access multiplexer (DSLAM) to deal with and a single type of aggregation router. Provisioning...

Business Challenges

Technical and organizational network management challenges are there to be conquered. As in most other areas, when the business proposition is sufficiently clear and there is lots of money to be made, the motivation and commitment to overcome those hurdles will become high enough that good solutions eventually follow. However, there are also aspects in the business environment that make network management and, specifically, the development of network management applications, challenging. This...

C

Call detail records (CDRs), 153, 306 BHCA, 3S0 completion rates, 3S0 costs, 420 management information (MIBs), 1lS-1ll CDRs (call detail records), 153, 306 Central Offices, 97 chain of command, top-down solution design, 363 metaschemata, 1S4 MIBs, 1S2 clear roles, 125 clearing alarms, 136 CLI (command-line interface), S1 overview of, 261-26S protocols, 26S-26l Show command, 109 close-session operation, Netconf, 2S3 CMIP (Common Management Information audit trails, 96 automated snapshots, 223...

Is for Configuration

We now turn to the second letter in FCAPS, C, which stands for configuration management. For the network to do what it is supposed to do, it might need to be first told what to do that is, configured. This is similar to having to initially set up a VCR so that it tunes to the proper channels, to select the proper input for connections from a video console, and later needing to program the VCR to record a particular show. Depending on the type of network equipment, its configuration can be much...

Categories of Management Information

The types of management information maintained in a MIB can be manifold (see Figure 6-3). The distinction of different categories of management information is important because, in general, management applications treat different categories differently and use them for different purposes. State information This is information about the current state of physical and logical resources, along with any operational data. It includes information about whether the device is currently functioning...

Chains of Command

Another related issue concerns how components in the solution interact with the managed devices in the network. When following a TMN-like hierarchy, upper-layer systems that need to interact with the network, such as to provision a service, instruct lower-layer systems to carry out requests, such as to configure a port on a device, until finally requests reach the network element. The responses are propagated back up accordingly. A major advantage of this architecture is that a clear hierarchy...

Challenges from Application Requirements

For starters, our integrated management system needs to be capable of providing all management functionality that is required. Of course, as we have seen in earlier chapters, so many functions are involved in managing a network that being able to provide them all through a single system seems unlikely. Even if it were possible to do so for one particular environment, different network providers have different needs, making the task of building something where one size fits all (and that would...

Challenges from Conflicting Software Architecture Goals

Another difficulty arises from the fact that different management functions can impose conflicting requirements on the software architecture that the integrated management system is to be based on. At times, those requirements could be difficult, if not impossible, to reconcile in a single system. This point is a little more subtle than the previous ones yet is just as important, so let us elaborate further on it. In Chapter 1, we mentioned that one of the challenges in building management...

Chapter

Explain the term network management in one sentence. Answer Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems. 2. We used a patient in intensive care as one analogy to explain network management. Can you think of areas in network management that this analogy does not capture Answer For example, the analogy does not effectively capture the administration and provisioning...

Setting the Stage

Analogy l Health Care the Network, Your Number One Patient Analogy 2 Throwing a Party 7 A More Formal Definition S The Importance of Network Management Many Reasons to Care 10 Cost l2 Quality l4 Revenue l5 The Players Different Parties with an Interest in Network Management 16 Network Management Users l The Service Provider l The Enterprise IT Department l7 The End User lS Network Management Providers l9 The Equipment Vendor l9 The Third-Party Application Vendor 20 The Systems Integrator 20...

Management Integration Putting the Pieces Together 331

The Need for Management Integration 332 Benefits of Integrated Management 332 Nontechnical Considerations for Management Integration 334 Different Perspectives on Management Integration Needs 336 The Equipment Vendor Perspective 336 The Enterprise Perspective 338 The Service Provider Perspective 339 Integration Scope and Complexity 340 Management Integration Challenges 342 Managed Domain 343 Software Architecture 345 Challenges from Application Requirements 345 Challenges from Conflicting...

Service Level Management Knowing What You Pay For 373

The Motivation for Service Level Agreements 374 Identification of Service Level Parameters 376 Significance 377 A Brief Detour Service Level Relationships Between Layered Communication Services 377 Example Voice Service Level Parameters 379 Relevance 381 Measurability 381 Defining a Service Level Agreement 3S2 Definition of Service Level Objectives 382 Tracking Service Level Objectives 384 Dealing with Service Level Violations 386 Managing for a Service Level 3SS Decomposing Service Level...

Management Metrics Assessing Management Impact and Effectiveness 407

Network Management Business Impact 4G8 Cost of Ownership 408 Enabling of Revenues 409 Network Availability 410 Trading Off the Benefits and Costs of Network Management Investments 410 Factors that Determine Management Effectiveness 411 Managed Technology Manageability 412 Management Systems and Operations Support Infrastructure 416 Management Organization 418 Assessing Network Management Effectiveness 418 Management Metrics to Track Business Impact 419 Management Metrics to Track Contribution...

On the Job with a Network Manager

A Day in the Life of a Network Manager 48 Pat A Network Operator for a Global Service Provider 4S Chris Network Administrator for a Medium-Size Business 54 Sandy Administrator and Planner in an Internet Data Center G Observations 2 The Network Operator's Arsenal Management Tools 63 Device Managers and Craft Terminals 4 Network Analyzers 5 Element Managers 5 Management Platforms Collectors and Probes 7 Intrusion Detection Systems 7 Performance Analysis Systems S Alarm Management Systems S...

The Basic Ingredients of Network Management

The Network Device 76 Management Agent 77 Management Information, MOs, MIBs, and Real Resources SG Basic Management Ingredients Revisited S3 The Management System 83 Management System and Manager Role S4 A Management System's Reason for Being S The Management Network 86 The Pros and Cons of a Dedicated Management Network 9G The Management Support Organization NOC, NOC, Who's There 93 Managing the Management 93 Inside the Network Operations Center 9 Chapter Summary 97 Chapter Review 98

The Dimensions of Management 103

Lost in (Management) Space Charting Your Course Along Network Management Dimensions 104 Management Interoperability Roger That 104 Communication Viewpoint Can You Hear Me Now 1 Function Viewpoint What Can I Do for You Today 1GS Information Viewpoint What Are You Talking About 110 The Role of Standards 111 Management Subject What We're Managing 114 Management Life Cycle Managing Networks from Cradle to Grave 115 Planning 116 Deployment 117 Operations 117 Decommissioning 118 Management Layer It's...

Management Functions and Reference Models Getting Organized 129

Of Pyramids and Layered Cakes 129 FCAPS The ABCs of Management 131 F Is for Fault 132 Network Monitoring Overview 132 Basic Alarm Management Functions 133 Advanced Alarm Management Functions 135 Alarm and Event Filtering 138 Alarm and Event Correlation 140 Fault Diagnosis and Troubleshooting 141 Proactive Fault Management 143 Trouble Ticketing 143 C Is for Configuration 143 Configuring Managed Resources 145 Auditing, Discovery, and Autodiscovery 146 Synchronization 148 Backup and Restore 151...

Management Information What Management Conversations Are All About 171

Establishing a Common Terminology Between Manager and Agent 171 MIBs 173 The Managed Device as a Conceptual Data Store I 3 Categories of Management Information I 5 The Difference Between a MIB and a Database I The Relationship Between MIBs and Management Protocols I S MIB Definitions 1SC Of Schema and Metaschema ISI The Impact of the Metaschema on the Schema IS3 Metaschema Modeling Paradigms IS4 Matching Management Information and Metaschema IS5 A Simple Modeling Example IS Encoding Management...

Management Communication Patterns Rules of Conversation 209

Layers of Management Interactions 2C9 Transport 2II Remote Operations 2II Management Operations 2I4 Management Services 2I5 Manager-Initiated Interactions Request and Response 216 Information Retrieval Polling and Polling-Based Management 2lS Requests for Configuration Information 2lS Requests for Operational Data and State Information 2l9 Bulk Requests and Incremental Operations 223 Historical Information 224 Configuration Operations 22 Failure Recovery 227 Response Size and Request Scoping...

Common Management Protocols Languages of Management 249

SNMP Classic and Perennial Favorite 249 SNMP Classic, a.k.a. SNMPvl 250 SNMP Operations 250 SNMP Messages and Message Structure 257 SNMPv2 SNMPv2c 25S SNMPv3 2 0 CLI Management Protocol of Broken Dreams 261 CLI Overview 2 l Use of CLI as a Management Protocol 2 5 syslog The CLI Notification Sidekick 267 syslog Overview 2 S syslog Protocol 270 syslog Deployment 272 Netconf A Management Protocol for a New Generation 275 Netconf Datastores 275 Netconf and XML 277 Netconf Architecture 27S Netconf...

Management Organization Dividing the Labor 293

Scaling Network Management 294 Management Complexity 294 Build Complexity 295 Runtime Complexity 297 Management Hierarchies 298 Subcontracting Management Tasks 299 Deployment Aspects 301 Management Styles 304 Management by Objectives and Policy-Based Management 308 Management by Exception 312 Management Mediation 312 Mediation Between Management Transports 316 Mediation Between Management Protocols 316 Mediation of Management Information at the Syntactic Level 318 Example A Syslog-to-SNMP...

Chapter Review

Explain the term network management in one sentence. 2. We used a patient in intensive care as one analogy to explain network management. Can you think of areas in network management that this analogy does not capture 3. Can you think of other areas in which you would expect analogies to network management to apply 4. Give two examples of how network management can help an enterprise IT department save money. 5. Give two examples of how network management can help a service provider increase...

Chapter Summary

In this chapter, to set the stage for the remainder of the book, we provided a brief overview of network management. Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems. In other words, network management is about running and monitoring networks. Many analogies can be drawn between network management and other areas where complex systems are monitored or where complex...

Collecting Performance Data

When you sit in front of a screen, you can monitor the performance of only a very small portion of your network for example, of a hot spot where there appears to be a problem. However, you might be interested in recording performance data from all over the network, even if you cannot constantly monitor it. It can sometimes be useful to have the option of looking at the data later if you discover a problem, to see if there are any indications in the data of how the problem developed, or to just...

Collectors and Probes

Collectors and probes are auxiliary systems that offload applications from simple functions. Collectors are used to gather and store different types of data from the network. An example is Netflow collectors, which collect data about traffic that traverses a router. Such data can be generated by routers in high volumes and is commonly represented in a format known as Netflow. Another example is loggers, which collect so-called syslog messages from network equipment that provides a trail of the...

Command Syntax Conventions

The conventions used to present command syntax in this book are the same conventions used in the IOS Command Reference. The Command Reference describes these conventions as follows Boldface indicates commands and keywords that are entered literally as shown. In actual configuration examples and output (not general command syntax), boldface indicates commands that are manually input by the user (such as a show command). Italics indicate arguments for which you supply actual values. Vertical bars...

Common Management Protocols Languages of Management

In the previous chapter, we provided an overview of management communication patterns and how management protocols are effectively applied in practice. In this chapter, we finally take a closer look at the management protocols themselves the specific languages that managers and agents use to communicate with each other and exchange requests, responses, and event messages. The presented protocols constitute a sampling of what are arguably the most important and widely deployed network management...

Communication Protocols

By definition, management applications communicate with other systems the network elements they manage, as well as possibly other management applications. At least as far as network elements are involved, this communication occurs using management protocols. Management protocols define the rules by which the systems that are involved in management communicate with each other. The technical properties of those communication mechanisms and their impact need to be well understood because they can...

Communication Viewpoint Can You Hear Me

As mentioned, the communication viewpoint deals with what kinds of messages are exchanged between managers and agents. Those messages generally constitute the core of a management protocol. An example of a management protocol is the Simple Network Management Protocol (SNMP). So why is it not sufficient for manager and agent to simply have IP connectivity IP connectivity means that they can exchange IP packets IP, of course, refers to the Internet Protocol, which defines basic rules that are...

Component Integration Levels and BottomUp Solution Design

As mentioned earlier, integration between components is not something that is binary something is either integrated or it is not. Instead, integration occurs at different levels integration can be shallow or deep. This is good news It means that it is often possible to start with very simple steps to begin integrating different applications and systems, and successively deepen the integration later. Integration touches on different technical aspects of the systems to be integrated. Many of...

Conferences and Workshops

Network management conferences and workshops constitute the best source of information about the current forefront of network management technology. There are several noteworthy conference series for each, proceedings are published that contain a wealth of papers describing current research projects. (Proceedings are essentially books whose chapters consist of papers that are also presented in talks at the event.) By nature, they focus mainly on the academic and research-oriented crowd. Those...

Configuration Operations

In the previous section, we discussed the communication patterns that are associated with management operations to retrieve management information from the network. Let us now turn to the second major category of management operations configuration operations. Configuration operations aim to change configuration information specifically, parameter settings that in some way affect the managed device's behavior. Where information-retrieval operations essentially involve nonintrusive reading of a...

Configuration Change Events

Maintaining an accurate database of current device and network configuration is critical to many applications. As explained in the previous chapter, many applications cache configuration information of devices for efficiency. Configuration-change events communicate the fact that a configuration change has taken effect at the device. Processing configuration-change events is an important and efficient technique to prevent the cache from going stale. Of course, the application that initiated the...

Configuring Managed Resources

At the core of configuration management are the activities and operations used to configure what is being managed. Ultimately, this involves sending commands to network equipment to change its configuration settings. In some cases, this involves only one device in isolation, such as configuring an interface on a port. In other cases, configuration operations that are performed on the devices are simply part of a bigger operation at the network level that involves changing the configuration of...

Considerations for Top Down Solution Design

Let us investigate a few aspects that should be considered when designing a solution architecture for an integrated operations support environment that is made from different collaborating components. The first aspect concerns ownership of different pieces of management information and the establishment of which component in the solution is in charge of what function. The second aspect concerns how the solution interacts with the managed devices and the establishment of clear chains of command...

Contents at a Glance

Part I Network Management An Overview 3 Chapter 2 On the Job with a Network Manager 47 Chapter 3 The Basic Ingredients of Network Management 75 Chapter 4 The Dimensions of Management 103 Chapter 5 Management Functions and Reference Models Getting Organized 129 Part III Management Building Blocks 1B9 Chapter 6 Management Information What Management Conversations Are All About 171 Chapter 7 Management Communication Patterns Rules of Conversation 209 Chapter B Common Management Protocols Languages...

Cost

One of the main goals of network management is to make operations more efficient and operators more productive. The ultimate goal is to reduce and minimize the total cost of ownership (TCO) that is associated with the network. The TCO consists essentially of the equipment cost, as well as the cost to operate the network (see Figure 1-5). Equipment cost is typically amortized over several years, to take into account the lifetime of the equipment. Operational cost includes cost such as operating...

Cost of Ownership

Of the three factors just listed, the impact of network management on the cost equation is the one that generally receives most attention. Because it is also the most obvious, we keep its discussion brief. Most obviously, network management affects the operational expense of running a network. An effective operations support organization, coupled with an effective operations support infrastructure, facilitates the job of the operations staff, allowing the staff to do more with less, increase...

Cross Section of Technologies

Building network management systems involves many different technical areas, each requiring its own specific subject matter expertise. Therefore, a firm grasp of a wide array of technologies is required to build effective nontrivial network management systems. This makes network management a technically demanding discipline because it requires a significant amount of breadth in technical expertise. Let us take a look at some of the technologies that are typically used in network management....

Custom Integration Approach

Another approach to management integration is to avoid relying on a management platform, but to instead custom-integrate multiple systems and applications that are otherwise independent. The resulting operations support infrastructure is often also called a solution. (One might wonder, a solution for what The answer to this question is, of course, a solution for the problem of how to provide an integrated management infrastructure.) Hence, a solution consists of multiple management systems and...

D

Common platform infrastructure, 356 configuration-change events, 239-240 costs, 416 craft terminals, 64 integration, 366 management systems, 85 MIBs, 177-178 data-collection capabilities, 414 DDOS (distributed denial-of-service) attacks, 160 decommissioning networks, 118 decomposing service-level parameters, of alarms, 139-140 of events, 305 deficits, SNMP, 202 defining management, 5-10 MIBs, 180-181 models, 110 object types, 195 SLAs, 382-388 syslog protocol extensions, 271 degradation,...

Dealing with Configuration Files

A third difference between management interactions for information retrieval and interactions for configuration operations is rooted in the way in which configuration information is maintained in the device. In some cases, configuration information is represented as managed objects in a MIB that can simply be set. In many cases, however, the MIB really consists of a configuration file that is, a text file containing line items with the settings that are in effect. These line items are sometimes...

Dealing with Service Level Violations

Despite all the best intentions of everyone involved, the possibility exists that service level objectives will be violated. To prepare for such cases, a good SLA needs to clearly spell out what will happen in such an event. Think of it as a prenuptial agreement between network provider and customer. What happens in case of a service level violation involves several aspects, each of which should be addressed in the SLA Restoring the agreed-to service level. This is what needs to happen first,...

Decommissioning

Eventually, network equipment might have to be decommissioned in an orderly manner. There can be many reasons for decommissioning. For example, new technologies replace old ones and lead to a general network upgrade, or requirements might have changed and certain types of network equipment are no longer needed. For example, as Internet dialup through modems is being replaced by Digital Subscriber Line (DSL), equipment that terminates telephone lines might be retired, giving way to other types...

Defining a Service Level Agreement

An SLA needs to answer a number of questions What will the service provider deliver what are the service level objectives How will service level objectives be tracked and verified What will happen if the service provider fails to deliver An SLA should specify other aspects as well, such as who the contacts are and the terms under which the SLA is allowed to be changed. However, the previous items constitute the most crucial aspects and are discussed in more detail in the following subsections.

Defining Network Management

As is the case with so many words, network management has many attached meanings. Therefore, some clarification is in order regarding what is meant by the term in this book. Speaking informally, network management refers to the activities associated with running a network, along with the technology required to support those activities. A significant part of running a network is simply monitoring it to understand what is going on, but there are also other aspects. What network management is all...

Definition of Service Level Objectives

When deciding which service level objectives to include, you need to make a number of considerations Determine which service level parameters and which service level objectives are really critical to your needs. To identify candidate service level parameters, remember that they must meet the criteria that we just discussed in the previous section of being significant, relevant, and measurable. Furthermore, you need to think about what target levels are really required. Of course, everybody...

Deployment Aspects

In addition to distributing the processing task, management hierarchies can reduce requirements for management communication bandwidth. With a management hierarchy, it might no longer be necessary to deploy all management functionality centrally in a NOC. Instead, it is possible to deploy subordinate management systems geographically close to the equipment that they are supposed to help manage for example, a particular branch location of an enterprise. This can help make more efficient use of...

Device Managers and Craft Terminals

Craft terminals, sometimes also referred to as device managers (not to be confused with element managers, discussed shortly), provide a user-friendly way for humans to interact with individual network equipment. Craft terminals are used to log into equipment one device at a time, view its current status, view and possibly change its configuration settings, and trigger the equipment to execute certain actions, such as performing diagnostic self-tests and downloading new software images....

Different Perspectives on Management Integration Needs

Let us now take a look at who has an interest in integrated management and why in other words, the different perspectives from which integrated management can be approached. The main difference between the perspectives is the scope of what management integration entails. We start with the perspective of the equipment vendor for whom integrated management has the most constrained scope. After that, we proceed to enterprises and service providers for whom the scope of what management integration...

Dimensioning Networks to Meet Service Level Objectives

When dimensioning a network to meet service level objectives, it helps to decompose the service into its individual components, as discussed in the previous section. Subsequently, the required dimensioning for each component is established, depending on its role and contribution toward meeting service level objectives. How to dimension that is, to determine which and how many resources to allocate for a given service instance is perhaps the most crucial aspect in provisioning a network for a...

Distributed Systems

By definition, management applications are distributed applications because they involve systems that manage and systems that are being managed. In addition to that, to meet requirements for scale as well as requirements for reliability and availability, it is often required to allow the managing system to be distributed itself. For instance, if a server runs out of horsepower to support a network of a given size, it is desirable for additional hosts to be added to increase management capacity....

E

Early warning systems, configuring, 397-400 echo requests, 398 economies of scale, 410 edit-config operation, Netconf, 282 effectiveness, 126 assessment, 411-412, 418-430 applications, 416-418 management organization, 418 maintenance, 422 metrics for scale, 425-426 tracking, 423-427 efficiency, 13, 126 338-339 elements, 23. See also NEs management, 65-66, 119 SDEs, 271 EMSs (element management systems), 338-339 enabling of revenues, 409 encoding management information, 189 messages, 107...

Eierlegende Wollmilchsaun and One SizeFits All Management Systems

To summarize the gist of the discussion to this point, trying to address the needs of multiple management applications in a single system inevitably leads to situations in which the best that can be accomplished might be a compromise hopefully acceptable, but not the best that could be achieved for each function individually. For all practical purposes, the likelihood of being able to build a truly comprehensive integrated application that fits everybody's needs is, well, slim. The German...

Element Managers

Element managers are systems that are used to manage equipment in a network. Typically, element managers are designed for equipment of a specific type and of a particular vendor in fact, they are often provided by an equipment vendor. Element managers are similar to craft terminals, in that they allow operators to access devices to view their status and configuration, and possibly modify their parameter settings. The functions of element managers, however, far exceed the functions of craft...

Enabling of Revenues

Less obvious, but just as important as the cost side of the equation is the fact that network management is also a big factor in increasing revenues that can be generated from a network investment. This occurs in a number of ways. Perhaps most important, network management can accelerate service rollout the speed at which new services can be introduced over a network and the speed at which they can be deployed. Service provisioning systems have a big role to play here. Obviously, the faster a...

Event Taxonomy

Events are used for many different purposes, notifying managers of many different types of event occurrences. Accordingly, they can be classified into a number of categories. The most common ones are as follows Alarms Unexpected events indicating a condition that typically requires management attention. Configuration-change events Events that inform of a configuration change that has taken effect at the device. Threshold-crossing alerts Events that inform that a performance-related state...

Example A SyslogtoSNMP Management Gateway

We return to the example of a management gateway that is supposed to convert syslog messages from a syslog agent into SNMP traps for an SNMP manager. One way this could be accomplished is as follows A simple syslog mediation MIB is defined, as shown in Figure 9-13. The basic idea behind this MIB is that it provides a notification type that is used to carry a syslog message. The different fields of the syslog message are conveyed through corresponding variable bindings in the SNMP trap message...

Example An SNMPtoOO Management Gateway

A second, more complicated example involves mediating between SNMP on the agent side and a management interface with an object-oriented (OO, for short) information model on the manager side. Object-oriented information models model the managed domain in terms of objects for example, a port, a connection, and a card on a device might all constitute objects, each representing a corresponding real-world counterpart. The definition of the information model specifies each kind of object that can...

Example Voice Service Level Parameters

The following are examples of service level parameters that are significant for a voice service. The examples illustrate some of the considerations that go into defining such parameters and how user concerns translate into service level objectives. The time that it takes until a user hears a dial tone when picking up the phone. Several service level objectives might be associated with the same service level parameter One objective would define the average time that should not be exceeded for...

Is for Fault

Fault management deals with faults that occur in the network, such as equipment or software failures, as well as communication services that fail to work properly. Fault management is therefore concerned with monitoring the network to ensure that everything is running smoothly and reacting when this is not the case. Effective fault management is critical to ensure that users do not experience disruption of service and that when they do, disruption is kept to a minimum. Fault management...

FAB and eTOM Oh Wait Theres More

Yet another functional management reference framework has been established by the Telemanagement Forum (TMF), a consortium of companies in the telecommunications space that includes service providers, equipment vendors, and system integrators. This framework is known as the Telecoms Operations Map (TOM) and has the concept of a management lifecycle at its center in a sense, it competes with the older OAM& P model, and because it is newer, it is not yet as established. Fundamentally, TOM...

Factors that Determine Management Effectiveness

The effectiveness of management is influenced at multiple levels, as Figure 12-2 shows At the level of the managed technology itself. This is often also subsumed under the term manageability, referring to the ease with which managed systems and devices allow themselves to be managed. At the level of management applications and operations support infrastructure. Finally, at the level of the management organization itself that uses the tools and infrastructure. Figure 12-2 Multiple Levels of...

Failure Recovery

One obvious difference between information retrieval and configuration operations concerns the possibility for failure. Because something on the device is to be changed, many more things can go wrong in the course of servicing a request than in the case when management information is retrieved. Here are some examples The device might not support a particular configuration option that is requested, it might currently not have the required system resources to fulfill the request, or the request...

Fault Diagnosis and Troubleshooting

Alarm management is a significant aspect of fault management so significant, in fact, that the two terms are often used synonymously. However, there is more to fault management than alarms. One other aspect concerns fault diagnosis and troubleshooting. Network diagnosis is conceptually not much different from medical diagnosis. The difference, of course, is the type of patient. To reach a medical diagnosis for a set of symptoms (for example, a rash), the doctor might want to take a look at...

FCAPS The ABCs of Management

To get a handle on the wide range of management functions that are required in an operational support environment, people often group them into a set of broad categories that are known as Fault, Configuration, Accounting, Performance, Security (FCAPS). This is the categorization that we use to go over the various functions. In many cases, function categories can be addressed independently of each other, in terms of both the systems supporting them and the organization performing these...

Feature vs Product

Traditionally, network equipment vendors have been interested primarily in one thing selling iron. This is what drives their revenues, profits, and, ultimately, their valuation as a company. Of course, other aspects generate revenue and profits for them, such as services. However, at the end of the day, the success of the vendor comes down to how well the network equipment products do in the marketplace. Of course, to drive the vendor's business, it is not sufficient to develop world-class...

Feedback Information

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Function Complexity

Function complexity results from the variety of different management functions that are to be integrated. Two factors determine function complexity the number of distinct functions that need to be integrated, and the depth with which you want integration to occur. This is characterized in the following equation again, a product, not a sum, for analogous reasons as for the previous equations Function complexity f( management functions) * f(integration depth) The fact that the number of functions...

Functional Division of Tasks

Question How do you swallow an elephant Answer One little piece at a time. The way to deal with a task of significant complexity is to divide it up into smaller parts. Already the Romans knew divide et impera. (Divide and rule.) When you can get your hands around each of the subtasks, you have a good handle on the entire problem. In some cases, of course, the subtasks still need to be divided up further, but you get the idea. Now there remains only one little detail how to divide the task of...

Geographical Distribution

Large networks can be geographically distributed around the globe, along with their users. The network must be managed and users supported globally and around the clock. Often this occurs in follow-the-sun fashion. This means that operational responsibilities get handed off at the end of an 8-hour workday from a network operations center in Europe to a center on the U.S. West Coast, then to Asia, and then back to Europe. The organization itself also must be equipped to handle such rotating...

Get Request

A manager uses a get request to retrieve management information that is, MIB objects from an agent. In addition to an identifier for the request, a get request includes as a parameter a list of variable bindings that specify which objects are requested. A variable binding is a name value pair of MIB objects. In this case, for the object value, a null value is given. After all, the manager is interested in the object values but does not know them if it knew what they were, it wouldn't have...

Get Response

An agent sends a get-response to a manager in response to a request. Contrary to what the name suggests, the responses are not restricted to get requests there are no separate responses defined for get-next and set requests. Instead, the agent sends a get-response for these as well. A get-response includes the following parameters The identifier of the request that it contains the response to. An error status that amounts to a response code that indicates whether the request was successful or...

Heterogeneity Complexity

Heterogeneity complexity defines the degree of uniformity, or lack thereof, of what is to be managed in an integrated fashion. Clearly, if only a single type of router that is deployed across the network needs to be managed, the task is a little simpler than in the case of 10 different equipment types from five different vendors. Accordingly, the heterogeneity complexity of a network can be roughly defined as the product of several factors that are functions of the following The number of...