Новая парадигма устранения сетевых неполадок | NETSCOUT
Техническое описание
| Техническое описание |

A NEW PARADIGM FOR
NETWORK PROBLEM SOLVING

48 процентов всех организаций в среднем тратят более половины дня для того, чтобы закрыть уведомления о неисправности
Это парадокс. По мере повышения надежности сетей организации по-прежнему тратят много времени на устранение неполадок, хотя от ИТ-специалистов требуют решать проблемы все быстрее и быстрее. This white paper discusses state-of-the-art network problem solving and how a new approach – based on the NETSCOUT OneTouch™ AT Network Assistant – can reduce troubleshooting time by one full week each month.

Are Problems a Thing of the Past?

Каждый год сети становятся надежнее. Новые стандарты обещают совместимость, новые устройства упрощают конфигурацию, а современные решения мониторинга, по словам их разработчиков, обнаруживают проблемы, до того как они пользователи их заметят. ИТ-отделы вступают в эпоху, в которой неполадки уйдут в прошлое.

Но так ли это? A recent research study of over 300 network professionals in large - and medium - sized organizations found that:
  • 48 процентов всех организаций в среднем тратят более половины дня для того, чтобы закрыть уведомления о неисправности
  • 46 процентов всех организаций имеют необходимость уменьшения времени, которое они затрачивают на закрытие уведомлений о неисправности.
  • Network professionals spend about 25 percent of their time solving problems
Почему это происходит в свете многих улучшений в ИT-сфере, созданных для того, чтобы исключить проблемы? Одно из объяснений состоит в том, что для каждого продвижения в надежности и простоте существует компенсирующее продвижение технологии, которое осложняет ситуацию: unified communications, 802.11ac, cloud computing or IPv6. Независимо от причины, многое еще предстоит достичь посредством улучшения продуктивности решения проблем.

To increase productivity, troubleshooting tools not only need to keep up with technology changes, but must continue to improve processes used to solve problems.

How Troubleshooting is Done Today

The vast majority (72 percent) of organizations do not follow a standardized troubleshooting process. Not only does this process vary within an organization but the tools used to troubleshoot problems vary substantially. Survey respondents reported using eight different types of tools to solve problems. В 47 процентах ситуаций было необходимо два или более инструментов. Со всей вариантностью в практиках устранения неисправностей и инструментах не является удивительным тот факт, что 63 процента сессий по устранению неисправностей продолжались более часа.

There is a part of problem solving that is worth considering separately. Во многих случаях технические специалисты не могут разрешить проблему сами. Sometimes they need additional help with especially difficult problems. In other instances, it’s because the problem lies outside their domain of responsibility, and they need to work with a separate group inside (server management or application developers) or outside (service providers or equipment vendors) the enterprise. Далеко не редкостью является ситуация, когда наше исследование показывает, что 41 процент всех вопросов требуют такого вида сотрудничества. This can take too long for at least two reasons. Во-первых, не всегда легко предоставить ответственным сторонам видимость проблемы, когда она возникает. Second, the technician may not have the ability to easily capture the trace files that are often required (19 percent of the time) for these problems.
To increase productivity, troubleshooting tools not only need to keep up with technology changes, but must continue to improve processes used to solve problems

Изучение методов разрешения проблем

This white paper refers to a NETSCOUT research study of 315 network professionals in April 2012. The respondents came primarily from medium- to large-sized networks in a variety of industries. Most of them were top-level networking support staff.

Рис. 1: Какие из этих инструментов вы использовали для устранения вашей последней пользовательской проблемы?

Рисунок 2: Сколько уведомлений о неисправности вы обрабатываете в течение обычного месяца?

Рисунок 3: What is your group’s average time to close a trouble ticket? Заметьте, что 48% сообщают о более чем 4 часах.

Рисунок 4: Что было основной причиной возникновения последней пользовательской проблемы, которую вы разрешили? (Допускаются множественные ответы.)

The survey asked respondents to identify the root cause of their most recent user-reported problem (respondents could select more than one root cause). The most common cause was network problems (wired or Wi-Fi), occurring in 27 percent of instances. However, end-user configuration or operation problems combined were at fault in 42 percent of cases.

The OneTouch AT identifies the most common network problems in about one minute1

Changing the Problem-solving Paradigm

At NETSCOUT, we looked to shorten the entire problem-solving process. The process, as described earlier, traditionally consists of two steps – solo troubleshooting and collaboration when necessary. To streamline troubleshooting, NETSCOUT developed a three-step process and designed a new tool based on it. The three steps are:

1. Автоматизированное тестирование
2. Поиск и устранение неисправностей
3. Сотрудничество

The OneTouch™ AT Network Assistant, enhances each of the steps and greatly reduces the time to solve problems.

Шаг 1: Автоматизированное тестирование

It may seem counterintuitive that adding a step reduces time. But if the additional step actually saves more time in subsequent steps, the total time is reduced. That’s the idea behind automated testing.

The OneTouch AT identifies the most common network problems in about one minute1. It performs a thorough network analysis from the end-user’s point-of-view. Such an analysis, performed manually, would take roughly one hour2. The OneTouch AT performs that same testing in about a minute (tests are configurable and can take anywhere from ten seconds to a few minutes, with most being less than a minute). Results are then compared against user-defined limits to provide a simple pass/fail result. This approach allows technicians to find the most common problems that result in end-user complaints.

Существует несколько преимуществ автоматизированного тестирования. Во-первых, оно намного быстрее стандартного тестирования методом проб и ошибок. Во-вторых, оно более тщательное, чем ручное, т. е. оно позволяет выявить проблемы, о которых сетевые специалисты могут даже не подозревать. В-третьих, с помощью автоматизированных тестов любой человек, независимо от уровня квалификации, выполнять проверку и выявлять такие проблемы.

Шаг 2: Поиск и устранение неисправностей

While the AutoTest uncovers a wide variety of problems on its own, not all problems can be found that way. The OneTouch AT provides a veritable arsenal of troubleshooting power to reduce the time spent in this phase.

AutoTest – even if the initial AutoTest does not identify the problem, all the measurement results are ready and available to help the technician understand what is happening. Further, the AutoTest can be modified in seconds and re-run to test a different server, application or wireless connection.

Wired Tests – a complete set of tests provide information on the cable, Power over Ethernet, the nearest switch and network services. The OneTouch AT features a web browser, Telnet and a SSH client to assist with configuration of network devices including switches and access points. It features a toner and can flash switch port lights to help locate unmarked cables in congested closets. A video probe can be connected to the OneTouch AT to inspect the endface of fiber optic connectors for contamination.

The OneTouch AT can pay for itself within 4 months with time savings while troubleshooting and validating networks
Wireless Tests – OneTouch AT provides more analysis of the Wi-Fi network than a library of wireless freeware and shareware tools, and provides answers in an easy to understand format. The OneTouch AT discovers all the networks, AP’s and clients in range and quickly identifies problems such as improper security, interference, bandwidth hogs, overloaded channels, unauthorized devices and more.

Шаг 3: Сотрудничество

Как было замечено ранее, для решения проблем сетевые специалисты регулярно должны работать с кем-либо еще. The process of getting the right information to the right people, however, can drag on for days. Even if the technician is able to work on other problems during this period, that’s little comfort to an end user who can’t get their job done or the IT manager missing targets for trouble ticket times.

The OneTouch AT includes features specifically designed to expedite collaborative troubleshooting with the Link-Live Cloud Service. With Link-Live Cloud Service, everything is always captured with zero-touch reporting, providing you with complete records of your work and results, at all times. Подобная исчерпывающая база данных позволяет легко идентифицировать изменения в сети. Нет никаких ограничений для хранения результатов и нет необходимости получать и передавать данные с тестеров в хранилище после окончания работы. This cloud service is available to all Handheld Network Tools: LinkSprinter, LinkRunner AT, and the AirCheck G2, all automatically upload their test results at the moment they happen. If you don’t have connectivity at that drop, the testers can buffer results, which are pushed to the Link-Live Cloud Service when connectivity returns. Техникам больше не нужно заботиться о хранении и передаче тестовых данных — не нужно и нажимать кнопку «Сохранить»! Они могут удвоить свою производительность и закончить проекты, на которые уходили недели, за несколько дней. In addition, managers can have access to the test results dashboards.

Reporting – a detailed report of everything that the OneTouch AT tested and observed will be recorded in the Link-Live Cloud Service. This allows the tech to show a colleague exactly what is happening when they are observing the problem. These results include results a less-experienced technician might not have looked at but are there for more knowledgeable team members to evaluate.

In-line Packet Capture – a trace file is indispensable for very difficult problems or as evidence to an outside group such as application developers, service providers or equipment suppliers. Для сбора этой информации обычно требуется изменить конфигурацию коммутатора или сетевого отвода. Это может занять 30 или более минут. Worse, many techs may not have access to switch provisioning or a tap. Это означает еще большую задержку, так как проблема переходит к другому человеку.

Вы можете выполнить поточный захват пакетов на OneTouch AT всего несколькими нажатиями без доступа к коммутатору или сетевому отводу. This means the tech can capture the problem packets immediately while the user demonstrates the problem.

Web Remote Interface – while it’s not always possible to get a colleague physically in the location of the problem, the OneTouch AT can be accessed and controlled through a remote device such as a PC, tablet or smartphone. Not only can the remote user see what the tech is seeing, but they can control the OneTouch AT and export trace files or reports to their device.

Camera – connect a webcam to the OneTouch AT USB port and the remote helper can see livevideo of the physical environment the tech is working in. This is useful if the tech is in a wiringcloset or a data center and the remote colleague needs to see the switch or patch panel, for example.

Savings

The first step in estimating savings from the OneTouch AT is to look at the time saved in each of the three parts of the test.

Automated Testing – Table 1 compares the amount of time it would take to perform the AutoTest functions with the actual time of the AutoTest. Время зависит от навыков техники и числа тестируемых приложений.

Troubleshooting – it’s less straightforward to quantify these savings, as it is highly dependent on the actual problem and the skill of the technician. Users of other NETSCOUT Handheld Network Test Solutions generally report 30 percent to 40 percent faster troubleshooting, but we will set that aside and consider it a “bonus” savings in addition to what is demonstrated here.

Collaboration – to quantify the time savings in these scenarios, we compared time to set up a packet capture using port mirroring (roughly 20 minutes) versus the inline packet capture with the OneTouch AT (three minutes). Если у техника нет доступа для изменения настроек коммутатора, экономия может быть еще существеннее.

Эффективное взаимодействие позволяет значительно сократить время обработки запросов на обслуживание. Без OneTouch AT получить все необходимые данные довольно сложно. Из-за этого запросы на обслуживание остаются без ответа в течение нескольких дней. Armed with the OneTouch AT, the first responder easily generates a report or a trace file and shares these plus provides remote access for the rest of the team in real time. So while the total amount of time the staff spends on a problem may not be reduced, the time the end user spends waiting for a resolution is greatly reduced.

Again, such a benefit is hard to quantify – so we won’t – but for many organizations this may be more valuable than actual hours saved for the department staff.

Заключение

An estimation of the savings expected from using the OneTouch AT is presented in Table 1. Even ignoring the time saved in solo troubleshooting and purchase of the top of the line model, one would expect payback in less than six months.

Экономия при использовании автотестирования
Запросов на обслуживание в месяц на техника 20 (среднее значение)
Минут на запрос 90
Время автотестирования 1 минута
Время для выполнения функций автотестирования вручную
(from Table 1)
60 минут
Сэкономленное время на запрос 59 минут
Сэкономленное время в месяц (ч) 19,7 на техника
Экономия за счет взаимодействия
Доля, требующая захвата пакетов (%) 19 % (среднее значение)
Число запросов, для которых требуется захват пакетов 3,8
Время подготовки захвата пакетов 20 минут
Подготовка захвата пакетов с помощью OneTouch AT 3 минуты
Сэкономленное время на захвате пакетов 17 минут
Сэкономленное время в месяц (ч) 1,1 на техника
Число пользователей 2 на OneTouch AT
Общее сэкономленное время 41 ч в месяц
Денежная экономия
Почасовая ставка 60 долларов США
Общая экономия в месяц 2 489 долларов США
Стоимость OneTouch AT 10 000 долларов США
Окупаемость 4,0 месяцев

Таблица 1: An estimation of time and cost savings provided by OneTouch AT.

Рисунок 5: Summarizes the concepts of this paper: the ways in which the OneTouch AT saves time throughout the entire problem-solving process as compared to traditional methods.

Приложение А. Час диагностики за одну минуту

Главная задача диагностики — выявить основную причину проблемы, но для этого могут понадобиться дополнительные действия. Например, когда вы идете к врачу, независимо от недуга, с которым вы столкнулись, сначала вас примет медсестра, которая измерит ваш вес, температуру, кровяное давление, а также изучит историю болезни. Это не только экономит время врача, но и позволяет выявить проблемы, которые могли остаться незамеченными.

Такая же концепция применяется и при тестировании сети. Since your team doesn’t usually include a nurse, the OneTouch AT automates a complete test of “network vital signs” into an AutoTest that compresses an hour of traditional testing into about a minute. The results are then compared against userdefined limits to provide a simple pass/fail result. Такой подход не только экономит время, но и помогает специалистам решать больше проблем.

Этап тестирования OneTouch Network
Assistant (автотест)
Традиционные методы
Базовое подключение (проводное или Wi-Fi) 1 минута Кабельный тестер, ПК, утилиты для проверки Wi-Fi 5 минут
Инфраструктурные службы Пк, утилиты 5 минут
Работа и производительность беспроводной сети Два ПК, iPerf 10 минут
Производительность сетевых служб и приложений Захват пакетов, анализатор протокола 40 минут
(три приложения)

Таблица 2: Функция автотеста OneTouch позволяет всего за одну минуту выполнить задачи, которые раньше отнимали целый час.

Basic Connectivity – OneTouch AT tests both wired and Wi-Fi connectivity. On the wired side, it checks the physical layer (including cabling and Power over Ethernet), identifies the switch port, speed and duplex settings and identifies the switch port and VLAN. For Wi-Fi, it verifies connectivity and security settings for the nearest AP and tests connection speeds.

Infrastructure Services – OneTouch AT tests availability and response time of DNS and DHCP across both the wired and wireless network.

Wireless Operation and Performance – the exclusive test measures the actual wireless performance by sending a stream of traffic out the wireless port, through the nearest AP, the wired infrastructure and back to its wired port. The test runs simultaneously in the reverse direction with programmable upstream and downstream rates. The test provides measurement results for throughput, loss, latency and jitter in both directions. These latter two measurements are vital for quality performance of real time application such as streaming video or voice over Wi-Fi.

Network Services and Application Performance – these tests provide a detailed breakdown of application performance by analyzing an actual interaction with the server/service under test. Seven different tests/applications are supported and can be customized for specific sites or applications whether hosted locally or through cloud-based providers.

The detailed breakdown provides the results shown in Figure 7 and shows the results for both the wired and Wi-Fi network side-by-side for easy comparison.

While the overall measurement can be used to quantify the performance of the application, the detail can be used to determine the cause of the slow performance, whether it’s the network, application server, or the DNS server. While an expert can provide this level of analysis in ten or twenty minutes with a protocol analyzer (once they have a trace file), the OneTouch AT provides it under a minute as part of a standard AutoTest.

Рисунок 6: The test measures performance of the wired and Wi-Fi network.

Рисунок 7: The application performance tests provide a detailed breakdown of the response time of servers and services.

Appendix B: List of problems that can be discovered by the OneTouch AT Network Assistant AutoTest

Fiber problems Wrong SFP/vendor mismatch, Dirty fiber endface*, Dead port/broken fiber, Low power
Twisted pair problems Open cable, Bad cable mapping, Shorted cables, Mislabeled/undocumented cables*, Too long cable, Dead port
PoE Not present or disabled, Switch unable to supply adequate power, Wrong pins, Low voltage, Non-Ethernet voltage, Low power under load, Class 4 negotiation mismatch
соединение Polarity mismatch, Low link level, Receive pair issues (MDIX), Speed mismatch, Duplex mismatch
Switch port Incorrect switch, Incorrect port, Incorrect data VLAN*, Incorrect voice VLAN*, Unstable switch uptime*, Switch congestion*, Switch errors*, FCS errors*, Frame size errors*, Other frame errors (7)*, Excessive broadcast traffic*, Excessive multicast traffic
Wi-Fi Security settings wrong, AP missing, AP misconfigured, AP not connected, WLAN controller problems*, Excessive noise*, AP congestion*, Channel over utilized*, Too many APs on channel*, AP overlap on channels*, Roaming problems*, Unauthorized APs*, Finding rogue APs*, Ad hoc networks*, Insufficient network coverage, Slow connection, Bandwidth hogs APs and client*, Bad client NIC*
Veri-Fi QoS settings wrong*, MTU problems*, Port problems*, Upstream bandwidth issues, Downstream bandwidth issues, IPv6 issues*, Excessive loss, Latency issues*, Jitter issues*, Sequencing issues*
DHCP Missing, Slow, Out of addresses, Incorrect lease time, Rogue DHCP server, Wired versus Wi-Fi configuration problems, Duplicate static IP address, IP address hijacked, Incorrect address delivery, Incorrect subnet delivery, Incorrect router address, Incorrect DNS address
DNS Missing, Slow, No secondary server*, Wired versus Wi-Fi configuration problems*
Шлюз Missing / Failed, Not IPv6 capable*, Unstable gateway uptime*, Overloaded*, Bad traffic*, Incorrect routing protocols*
Discovery Wrong VLAN*, Wrong subnet*, Unexpected IPv4/IPv6 devices
Web (HTTP) DNS lookup failure, DNS lookup slow, Server unavailable, Slow connectivity, Server slow to start, Server slow to complete, Wired versus Wi-Fi transport problems, IPv4 versus IPv6 transport problems
Ping (ICMP) DNS lookup failure, DNS lookup slow, Server unavailable, Slow connectivity, MTU misconfigurations, Wired versus Wi-Fi transport problems, IPv4 versus IPv6 transport problems

Appendix B: (continued)

Соединение (TCP) DNS lookup failure, DNS lookup slow, Server unavailable, Slow connectivity, Firewall misconfigured for ports, Wired versus Wi-Fi transport problems, IPv4 versus IPv6 transport problems
Многоадресная передача (IGMP) Server not multicasting, Switch IGMP snooping disabled, Incorrect port configuration, Server authentication
Файл (FTP) Slow WAN, DNS lookup failure, DNS lookup slow, Server unavailable, Slow connectivity, Server slow to start, Server slow to complete, Wired versus Wi-Fi transport problems, IPv4 versus IPv6 transport problems
Видео (RTSP) Slow WAN, DNS lookup failure, DNS lookup slow, Server unavailable, Slow connectivity, Server slow to start, Server slow to complete, Wired versus Wi-Fi transport problems, IPv4 versus IPv6 transport problems

* May require a secondary test after the AutoTest.

1 See appendix A, “An Hour of Troubleshooting in One Minute”
2 See appendix B, “Problems That can be Discovered by the OneTouch AT Network Assistant AutoTest”

 
 
Powered By OneLink