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....

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...

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....

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...

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...

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...

B

Background noise, 377 backlogs, orders, 421 backups, 151 autoconfiguration, 306 functions, 418 procedures, 96 dimensioning, 393 monitoring, 10 base applications, 359. See also applications BEEP (Block Extensible Exchange Protocol), benefits of integrated management, 332-334 BHCA (busy hour call attempts), 380 billing accounting, 152-153 FAB, 163-164 services, 339 systems, 72 blacklist ports, 160 Block Extensible Exchange Protocol) (BEEP), buffers, dejitter, 379 build complexity, 295-297 bulk...

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...

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 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

Both the provider and the customer of a service should be concerned with service level monitoring. Why is this so Answer The customer might not know for sure whether he is indeed getting the service level that was agreed to. 2. Assume that you are a service customer and are about to enter an SLA with a service provider to provide you with video phone service across your enterprise network. Can you think of some service level parameters that you might want to include in service level objectives...

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...

Chapter Review

Is running a network only a matter of network management technology, or are there other considerations 2. What does Pat's employer use to track the resolution of problems in the network 3. How does the integration of the work order system with the trouble ticket system make Pat's job easier 4. Which network provider do you think will be more vulnerable to human failures by operations personnel, Pat's or Chris's 5. Which of the following can be used as management tools A. alarm management...

Chapter Summary

In this chapter, we took a look at a few scenarios that illustrate how networks are being managed in practice and the variety of tasks that are involved. We followed three fictitious network operators and administrators Pat in the Network Operations Center of a large service provider, Chris in the IT department of a medium-size business, and Sandy in the Internet Data Center of a large enterprise. The three scenarios represented operational support environments that differ greatly, as do the...

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...

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 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...

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 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...

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,...

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....

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...

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...

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...

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...

How This Book Is Organized

This book is intended to be read cover to cover because later chapters build on concepts and principles that earlier chapters introduce. Nevertheless, many chapters are relatively self-contained, which should make it fairly easy to move between chapters. The chapters of this book are grouped into four parts Part I, Network Management An Overview, provides an overview of what network management is about and why it is relevant. It also conveys an informal understanding of the functions, tools,...

Inside the Network Operations Center

One important aspect of the management support organization concerns where it is physically located. This might not be a consideration for a small business running a few routers in one or two locations, but it does matter for a service provider with a global presence, interconnecting thousands of sites. The place from which large networks is managed is generally termed the Network Operations Center (NOC). From here, the bulk of management-related activities is carried out, from monitoring the...

Interrupt Driven System Characteristics

An important aspect of network management concerns keeping track of the health of the network. In particular, this involves monitoring the network for any alarms that network elements emit. Network elements emit alarms whenever unexpected events occur that might require management attention. In many cases, this involves unusual conditions or failures in the network that require immediate action to avoid degradation of service to customers. With communications services, time is money quite...

Introduction

Network management is an essential factor in successfully operating a network. As businesses become increasingly dependent on networking services, keeping those services running becomes synonymous with keeping the business running. Properly performed, network management ensures that services provided over a network are turned up swiftly and keep running smoothly. In addition, network management helps to keep networking cost and operational cost under control. It ensures that networking...

Inventory Systems

Inventory systems are used to track the assets of a network provider. They come in two flavors Network inventory systems track physical inventory in a network, mainly the equipment that is deployed, but sometimes also spare parts. Inventory information includes the type of equipment, the software version that is installed on it, cards within the equipment, the location of the equipment, and so forth. We encountered a network inventory system in the scenario involving Pat when the network...

IP Flows

Netflow communicates statistical information about IP-based data traffic that flows over a router. The statistics are provided on a per-flow basis. A flow consists of all traffic that belongs to the same communication context, basically IP data packets that belong to the same connection. Of course, IP is completely packet based and has no notion of a connection that is its whole point. However, chances are, applications that communicate with each other using IP will exchange in general more...

L

LAN (local area network), 301 large responses, fragmentation, 214 layers communication services, 377-379 content, 279 management, 118 business, 121 elements, 119 NEs, 121 network, 120 services, 120-121 operations, 279 transport, 278 LEDs (light emitting diodes), 136. See also alarms levels of management effectiveness, 411 lifecycles decommissioning, 118 deploying, 117 operations, 117 planning, 116 TOM, 163 light emitting diodes. See LEDS limitations of syntactic information mediation, 321-322...

Layers of Management Interactions

In all networked systems, communications are structured into layers. This includes management communications. Before diving into the patterns of communication exchanges between managers and agents, let's talk briefly about how management communications are generally structured into layers that is, the different roles and functions that you will find in layers of a management protocol stack. The topmost layer of a communications stack is generally the application layer, which provides...

Lost in Management Space Charting Your Course Along Network Management Dimensions

If we think of network management as a multidimensional space, the question arises as to which dimensions or axes span that space and what coordinates will be defined for each axis. This is important because, when faced with any problem, it can be tremendously helpful to know how to divide the problem into different aspects. Each aspect corresponds to one of the dimensions. If the dimensions are identified in such a way that they are independent of each other, we call them orthogonal. When...

Managed Domain

As mentioned earlier, the challenge of providing integrated management is compounded by the fact that, just as the importance of integrated management grows, the complexity of what needs to be managed that is, of the managed network or the managed domain is also increasing. For one, this phenomenon is related to scale that is, to the number of network devices. More important, it is related to their heterogeneity. Heterogeneity refers to the fact that different types of devices need to be...

Management Communication Patterns Rules of Conversation

Regardless of the particular management protocol that is used, interactions between managers and agents follow certain basic patterns. This chapter takes a look at those patterns that is, how managers and agents interact. We discuss tradeoffs and the profound impact that the presence or absence of certain management interface capabilities has on aspects such as the efficiency of management communications, management application scale and performance, and the robustness of management against...

Management Functions and Reference Models Getting Organized

This chapter picks up right where we left off in our discussion of management dimensions in the previous chapter. Specifically, it takes an in-depth look at the function dimension of network management, a big topic that deserves its own chapter. This concerns the range of functionality that management applications and operational support systems need to cover. We discuss these functions along the lines of several management reference models, which do a great job of organizing these functions....

Management Hierarchies

As indicated earlier, a single system is generally not sufficient to manage a network. Instead, the work needs to be distributed. Let's look at a real-life analogy. Consider a person who owns and runs a small business. As the business grows, the business owner might no longer be able to manage the business single-handedly. So she gets help. She still wants to be in charge of running the overall business, but she distributes certain tasks across her people. Eventually, she starts building an...

Management Information MOs MIBs and Real Resources

In general, many aspects of a network device (such as a router or a switch) are important for its management. For example, the device has a network address, it is of a certain type, and it has software installed of a certain revision. If the device is a router, it might be running a variety of routing protocols. The device might consist of a rack-mountable chassis with a fan for cooling, a central processor module, and a set of expansion slots. Furthermore, the device might contain a set of...

Management Information What Management Conversations Are All About

When a manager and an agent communicate, they ultimately talk about the device that is being managed. (Actually, this is not entirely correct as you know by now, they could, for example, also talk about a service. For the purposes of the discussion here, however, we assume that the managed entity that is being represented by the agent is indeed a device.) For example, the manager might ask the agent how many packets have been sent over one of the device's interfaces, or the agent might send an...

Management Integration Challenges

Several factors make management integration a challenge. They have to do with the different dimensions along which integration occurs On one hand, management functions need to be integrated across the managed domain the different devices, networking technologies, and services that need to be managed and to which the same management function applies. On the other hand, different management functions have to be integrated as well. This leads to interesting challenges from a software-engineering...

Management Integration Putting the Pieces Together

As we saw in earlier chapters, managing a network involves a great variety of functions from monitoring devices in the network to provisioning services, from diagnosing networking problems to planning for optimum network performance, from detecting security breaches to assessing the impact of planned network maintenance on existing services and customers. One of the challenges in network management indeed, some would argue, the holy grail in network management lies in providing operational...

Management Interoperability Roger That

For a managing system and a managed device to interoperate, it is not sufficient for the systems to be merely connected that is, to have a physical or a Layer 3 connection that allows them to exchange data packets. This, of course, is a prerequisite. But much more is required. They need to speak the same management language. When the manager sends a management message, the agent needs to understand the message. For example, the agent needs to understand that...

Management Layer Its a Device No Its a Service No Its a Business

Network management is not just a multidimensional but also a multilayered problem space. At one layer, the concern is with managing individual devices. For example, each device must have the right software patch installed and must be monitored to make sure that it is running properly. These tasks apply regardless of what devices are actually used for in the network for example, whether they route IP traffic in the core of the network, whether they connect end users to the network, or whether...

Management Life Cycle Managing Networks from Cradle to Grave

Typically, network management is associated with keeping a network running. However, this assumes that a network is already in place. But how did it get there How are networks born, and how do they and the components in them die These different stages are referred to as the life cycle of a network and the services running over it. This life cycle is accompanied by a management life cycle. At inception, networks require planning. After planning comes deployment new equipment needs to be...

Management of Security

Management of security involves managing security of the network itself, as opposed to security of its management. Unfortunately, as we all know, in these days, online security threats are all too common. In many cases, security threats target not so much the network, but devices connected to the network PCs of end users, for example, or systems that host websites for corporations. In addition, the network infrastructure itself might come under attack. Common security threats include but are by...

Management Operations

The Management Operations layer is at the core of the management protocol stack. It provides the actual management primitives that is, the base operations that are used to manage the network. Management primitives include different types of management requests, responses to those management requests, and events, all of which are explained in much more detail in the remaining sections of this chapter. The specific primitives that are available depend on the specific management protocol....

Management Organization Dividing the Labor

You learned earlier in this book that management tasks are typically split up and jointly accomplished by systems that play different roles. The managing system, in a manager role, communicates with a managed system in an agent role. This suggests that management is typically organized in what amounts to a client server model, in which a management application (one client) manages the various systems and devices on the network (many servers). However, this is not the only way in which...

Management Platforms

Management platforms are general-purpose management applications that are used to manage networks. The functionality of management platforms is generally comparable to that of element managers. However, management platforms are typically designed to be vendor independent, offering device support for equipment of multiple vendors. Typically, the primary task of a management platform is to monitor the network to make sure it is functioning properly. Therefore, it was also the main tool that Chris...

Management Subject What Were Managing

As mentioned and depicted in Chapter 1, Setting the Stage, in Figure 1-4, there are different kinds of networked systems that require management. Network management is often categorized into different subdisciplines to reflect that distinction Network management, in a narrower sense, deals with the management of communication networks and the resources in the network that are required to establish end-to-end communications. For example, this includes the routers and switches in a network, or...

Management System and Manager Role

The terms manager and management system are often used synonymously. Strictly speaking, this is not quite correct, and, in general, care should be taken to distinguish a manager (the role) from a management system (the application). This is because, for various reasons, it might make sense for the same system to play both agent and manager roles. For example, one network element might act as a management proxy to another. In this case, the network element plays the agent role in interacting...

Management Transactions

Sometimes management applications would like not having to issue a request response pair for each configuration operation or management action, but instead be able to group several commands together and have them execute together as one unit. This is often the case when services need to be provisioned over a network. Consider the simplified example of a service provider that wants to provision a digital subscriber line (DSL) service, as Figure 7-14 illustrates. Figure 7-14 Provisioning a DSL...

Manager Initiated Interactions Request and Response

Let us now turn to the way in which actual interactions between managers and agents, or management applications and managed devices, take place. Here we take a look at how management operations are used to conduct effective management communications. We start with interactions that are initiated by the manager. Interactions that are initiated by the agent are the subject of the next section. The patterns of interactions between managers and agents that are described are largely independent of...

Managing the Management

The management support organization ultimately is responsible for making sure that the network is being run effectively and efficiently. It needs to perform such tasks as were presented in the previous chapter, including but not limited to these Monitoring the network for failures Diagnosing failures and communication outages if they occur, and planning and carrying out repairs Provisioning new services, and adding and removing users to and from the network Keeping an eye on performance of the...

Mediation of Management Information at the Semantic Level

Mediating management information without the limitations of the syntactic transformation approaches requires a semantic understanding of the management information involved. This means that custom translation rules need to be crafted, mapping the mediated management information to the target information model. For example, in the case of mediation from syslog (agent) to SNMP (manager), it would be necessary to determine which specific syslog messages should trigger which specific SNMP traps,...

Modeling Management Information

We mentioned several times that the management information that an agent exposes across its management interface constitutes an abstraction of the managed device. This abstraction is based on a model of the real world, and information in the MIB is an instantiation of this model. Because it is used for management purposes, the model includes aspects that are relevant for management and omits aspects of the real world that are not it abstracts them away. For example, the software revision that...

Monitoring Service Level Parameters

Different techniques exist for monitoring performance and quality of service level parameters that are the subject of service level objectives Analyzing management information. This includes the following NetFlow and IPFIX records, which contain a lot of information about network flows SNMP MIBs, which include many objects with information about device state and device performance, and which therefore may be regularly polled for this information syslog messages, which could indicate certain...

N

Name-resolution services, common platform infrastructure, 357 naming structures, MIB-2, 194 native traps, 321 navigation, row-by-row (get-next requests), 253 need for integrated management, 336-340 NEs (network elements), 76 architecture, 278-281 data stores, 275-277 operations, 281-284 XML, 277 Netflow, 284 aggregation collection, 305 IP flows, 284-286 protocols, 286-288 network elements. See NEs Network Operations Centers. See NOCs network-discovery services, common platform infrastructure,...

Netconf Operations

At this point, we can finally turn toward the guts of Netconf, the operations layer. As mentioned, Netconf is built around the notion that management information in general, and specifically configuration information, can be thought of as being contained in a conceptual datastore. In the case of configuration information, this datastore is a configuration file, in short referred to as config. Not coincidentally, this resembles how things are handled using CLI on a router. Different examples of...

Netflow Protocol

On an individual router, with traffic coming from and going to all kinds of different directions, at any point in time there may be tens of thousands of flows in progress, depending on the router's capacity. This obviously leads to a huge volume of flow data that needs to be collected and transferred. At the same time, the data is extremely uniform basically, it is the same data that is of interest for each flow. Hence, there is only one type of record to be transferred. This observation is...

Network Maintenance Considerations

Finally, a few remarks on network maintenance Maintenance operations such as routine backups or hardware or software upgrades can potentially be disruptive for services running over the affected equipment. However, unlike sudden failures or shifts in usage patterns that fall outside the control of the service provider, how to perform maintenance is completely within the providers' control. Care should be taken to do the proper homework in this area because unintended or unanticipated service...

Network Management

The next layer in the TMN hierarchy is the network management layer. In the context of TMN, network management refers just to this one layer. In this section, the term is accordingly used in a narrower sense than elsewhere in this book, where it refers not only to one of several management layers, but to the discipline of managing networks as a whole. The network management layer involves managing relationships and dependencies between network elements, generally required to maintain end-to-end...

Network Management Complexities From Afterthought to Key Topic

A little earlier, we compared network management to running a big party. This analogy is actually appropriate in more ways than one When deciding to throw a party, no one thinks at first of the effort that goes into planning the party, the logistics, the cleanup you think of the party itself and how much everyone will enjoy it. And certainly no one throws a party just for the sake of the work that it involves, but for the fun they expect out of it. This is not unlike the situation with...

Nontechnical Considerations for Management Integration

This book deals mainly with management technology, so our discussion of management integration focuses on its technical aspects. However, it should be mentioned that management integration is not only a technical problem involving management systems and applications. There is also significant organizational dimension that involves the structure of the network provider organization that manages the network. In fact, the issues with management integration at the technical level mirror in many...

On the Difference Between Billing and Accounting

Accounting management is often associated simply with billing, which is actually only one aspect. Billing is a common function that is performed for most businesses, whether they are rental car agencies, house-cleaning services, or restaurants. The business in this case is, of course, providing communication services. Writing the bills themselves, keeping track of customer data, and sending payment reminders is pretty similar for all these business. The domain specifics come in with regards to...

On the Job with a Network Manager

This chapter presents a number of scenarios to give an impression of the types of activities that are performed by people who run networks for a living. We refer to them collectively as network managers, although they perform a wide variety of functions that have more specialized job titles. In fact, strangely enough, the term network manager is rarely used for the people involved in managing networks. Instead, terms such as network operator, network administrator, network planner, craft...

Operational Support Infrastructure

For example, if different groups are responsible for equipment provisioning and for monitoring, very little can be gained from trying to integrate provisioning and monitoring systems. However, much can be gained from trying to integrate the provisioning applications for equipment from different vendors, and alarm management applications from different vendors. By the same token, if different groups are responsible for the core and access portions of the network, management systems do not have...

Organization and Operations Challenges

Small networks, such as those deployed by small businesses, might be run by a single person or network administrator as a part-time job. In those cases, how to run the network isn't much of an organizational issue The network administrator is in charge, and if problems arise that the network administrator cannot solve (or if the network administrator is out sick), customer support by a third party, by the equipment vendor, or by a consultant is only a phone call away. In addition, many...

Placing a Value on Network Management

Although network management is vitally important, there is also a flip side Network management costs money. The amount of investment in network management must be justified, and this ultimately is a business decision. It must be justified by expected cost savings or increased revenues. Ideally, the value proposition must be quantifiable in dollars. Return-on-investment models for network management are needed. Unfortunately, such models can be hard to come by. In general, service providers...

Proactive Fault Management

Most fault management functionality, such as alarm management, is, by nature, reactive it deals with faults after they have occurred. However, proactive fault management is also possible that is, taking steps to avoid failure conditions before they occur. This includes, for instance, the previously mentioned injection of tests into the network to detect deterioration in the quality of service and impending failure conditions early, before they occur. Proactive fault management can also include...

Quality

Other operational aspects are not related to cost but are equally important. One such aspect concerns the quality of the communications and networking services that are provided. This includes properties such as the bandwidth that is effectively available, or the delay in the network, which, in turn, is a factor in the responsiveness a user experiences when using services over a network. Quality also includes the reliability and the availability of a communications service As an end user, can I...

Quantifying Management Integration Complexity

One could state in a simplified manner that the inherent complexity of providing integrated management for a given managed domain is the product of several factors. This can be expressed as follows Management integration complexity scale complexity * heterogeneity complexity * function complexity We take a closer look at each of those factors in the following subsections. Note that the factors that contribute to management integration complexity are multiplied by one another, not merely added....

R

Rack-mounted equipment, 53 read primitives, 215 real resources, 80-82, 175 reassembly, PDUs, 213 receivers, syslog messages, 272 reconciliation, 149 records CDRs, 153, 306 Netflow, 305 recovery, 151, 227-228 reducing interdependencies, 353 redundancy alarms, 139 integrated management, 333 workflow, 416 applying, 164-165 FAB, 163-164 FCAPS, 131 accounting management, 151-155 configuration management, 143-151 fault management, 132 limitations, 161 performance management, 155-158 security...

Remote Operations

The Remote Operations layer offers three distinct functions that complement and perform important services for the Management Operations layer on top association control, remote operations support (in Figure 7-1, this is depicted a little simplified as RPC for remote-procedure call), and encoding of payload data. In many cases, those functions are provided not by a dedicated protocol, but by the management protocol that also provides the functionality of the Management Operations layer on top....

Scale

Parents of young children should be able to relate to the following scenario Try babysitting a toddler for a few hours. When she is hungry, she requires something to eat you should make sure she drinks enough so she doesn't get dehydrated perhaps she needs her diaper changed once in a while and a little entertainment to keep her occupied, so you read her a story and offer her some Legos. Doable. Now imagine a toddler birthday, with 20 toddlers and no one there to help you, and things become a...