Sdscompany.ru

Компьютерный журнал
0 просмотров
Рейтинг статьи
1 звезда2 звезды3 звезды4 звезды5 звезд
Загрузка...

No access to the channel

access to channel

1 access grant channel

  1. канал разрешенного доступа

канал разрешенного доступа
Выделенный канал управления, используемый базовой станцией для организации прямого доступа к любой мобильной станции.
[Л.М. Невдяев. Телекоммуникационные технологии. Англо-русский толковый словарь-справочник. Под редакцией Ю.М. Горностаева. Москва, 2002]

Тематики

  • электросвязь, основные понятия

2 access grant channel

3 access to channel

4 access-grant channel

5 access to channel

6 access grant channel

7 access grant channel

8 access channel

  1. канал доступа

канал доступа
Канал, по которому происходит обмен сигналами между работающими станциями в процессе установления связи. При передаче запросов от нескольких станций в канале возможно возникновение конфликтов.
[Л.М. Невдяев. Телекоммуникационные технологии. Англо-русский толковый словарь-справочник. Под редакцией Ю.М. Горностаева. Москва, 2002]

Тематики

  • электросвязь, основные понятия

9 access channel

10 access channel

11 Access Channel

12 access channel

13 access channel

См. также в других словарях:

Access (TV channel) — This article is about the television channel in Alberta. For the American infomercial channel, please see Access Television Network. Infobox Broadcast call letters = CJAL TV / CIAN TV city = station station slogan = The Education Station… … Wikipedia

Channel Tunnel — Map of the Channel Tunnel Overview Location English Channel (Strait of Dover) Coordinates Folkestone … Wikipedia

Access — may refer to:Companies and organizations* ACCESS (Australia), an Australian youth network * Access Co., a software company * AirCraft Casualty Emotional Support Services * Arab Community Center for Economic and Social Servicespace and technology* … Wikipedia

Channel Zero (company) — Channel Zero Inc. Type Private company Industry Media Founded 2000 Headquarters … Wikipedia

Channel access method — In telecommunications and computer networks, a channel access method or multiple access method allows several terminals connected to the same multi point transmission medium to transmit over it and to share its capacity. Examples of shared… … Wikipedia

Access Television Network — This article is about the American infomercial channel. For the educational television channel in Alberta, please see Access (TV channel). Access Television Network (ATN) is a company based in Irvine, California which distributes infomercials and … Wikipedia

Channel capture effect — The channel capture effect is a phenomenon where one user of a shared medium captures the medium for a significant time. During this period (usually 16 frames)[clarification needed], other users are denied use of the medium. This effect was first … Wikipedia

Channel 6 (Ireland) — Infobox TV channel name = Channel 6 logofile = Channel 6 (Ireland).png logosize = logoalt = launch = 20:00 IST, 30 March 2006 closed date = share = share as of = share source = owner = Channel 6 Broadcasting Limited (TV3 takeover pending… … Wikipedia

Channel-link — (C Link) by National Semiconductor is a high speed interface for cost effectively transferring data at rates from 250 megabits/second to 6.4 gigabits/second over backplanes or cables. National Semiconductor introduced the first Channel Link… … Wikipedia

Channel 31 (Australia) — Channel 31 is the frequency currently reserved for free to air community television (CTV) stations in the major Australian capital cities. Each station is a not for profit entity and is subject to specific provisions of the Broadcasting Services… … Wikipedia

Access control — is the ability to permit or deny the use of a particular resource by a particular entity. Access control mechanisms can be used in managing physical resources (such as a movie theater, to which only ticketholders should be admitted), logical… … Wikipedia

Списки доступа ACL. Настройка статического и динамического NAT

Списки доступа (access-lists) используются в целом ряде случаев и являются механизмом задания условий, которые роутер проверяет перед выполнением каких-либо действий. Маршрутизатор проверяет каждый пакет и на основании вышеперечисленных критериев, указанных в ACL определяет, что нужно сделать с пакетом, пропустить или отбросить. Типичными критериями являются адреса отправителя и получателя пакета, тип протокола. Каждый критерий в списке доступа записывается отдельной строкой. Список доступа в целом представляет собой набор строк с критериями, имеющих один и тот же номер (или имя). Порядок задания критериев в списке существенен. Проверка пакета на соответствие списку производится последовательным применением критериев из данного списка (в том порядке, в котором они были введены). Пакет, который не соответствует ни одному из введенных критериев будет отвергнут. Для каждого протокола на интерфейс может быть назначен только один список доступа. Как пример ниже приведена таблица списка управления доступом по умолчанию:

Без ACL — по умолчанию при создании конечной точки ей все разрешено.

Разрешить — при добавлении одного или нескольких диапазонов «разрешения» все остальные диапазоны по умолчанию запрещаются. Только пакеты из разрешенного диапазона IP -адресов смогут достичь конечной точки виртуальной машины.

Запретить — при добавлении одного или нескольких диапазонов «запретить» все другие диапазоны трафика по умолчанию разрешаются.

Сочетание разрешения и запрета — можно использовать сочетание правил «разрешить» и «запретить», чтобы указать вложенный разрешенный или запрещенный диапазон IP -адресов.

Рассмотрим два примера стандартных списков:

# access-list 1 permithost 10.0.0.10 — разрешаем прохождение трафика от узла 10.0.0.10.

# access-list 2 deny 10.0.1.0 0.0.0.255 — запрещаем прохождение пакетов из подсети 10.0.1.0/24.

Практическая работа 9-1. Создание стандартного списка доступа

Списки доступа бывают нескольких видов: стандартные, расширенные, динамические и другие. В стандартных ACL есть возможность задать только IP адрес источника пакетов для их запретов или разрешений.

На рис. 9.1 показаны две подсети: 192.168.0.0 и 10.0.0.0.

Постановка задачи

Требуется разрешить доступ на сервер PC1 с адресом 192.168.0.12, а PC0 c адресом 192.168.0.11 – запретить ( рис. 9.2).

Соберем данную схему и настроим ее. Настройку PC0 и PC1 выполните самостоятельно.

Настройка R0

Интерфейс 0/0 маршрутизатора1841 настроим на адрес 192.168.0.1 и включим следующими командами:

Второй интерфейс маршрутизатора (порт 0/1) настроим на адресом 10.0.0.1 и так же включим:

Настройка сервера

Настройки сервера приведены на рис. 9.3.

Диагностика сети

Проверяем связь ПК из разных сетей ( рис. 9.4).

Приступаем к решению задачи

Правило запрета и разрешения доступа будем составлять с использованием стандартных списков доступа (ACL). Пока не задан список доступа на интерфейсе всё разрешено (permit). Но, стоит создать список, сразу действует механизм «Всё, что не разрешено, то запрещено». Поэтому нет необходимости что-то запрещать (deny) – указываем что разрешено, а «остальным – запретить» подразумевается автоматически. По условиям задачи нам нужно на R0 пропустить пакеты с узла 192.168.0.12 на сервер ( рис. 9.5).

Читать еще:  Что из перечисленного не является access

Применяется данное правило на интерфейс в зависимости от направления (PC1 расположен со стороны порта Fa0/0) – рис. 9.6. Эта настройка означает, что список доступа (правило с номером 1) будет действовать на интерфейсе fa0/0 на входящем (in) от PC1 направлении.

Входящий трафик (in) — этот тот, который приходит на интерфейс извне. Исходящий (out) — тот, который отправляется с интерфейса вовне. Список доступа вы можете применить либо на входящий трафик, тогда неугодные пакеты не будут даже попадать на маршрутизатор и соответственно, дальше в сеть, либо на исходящий, тогда пакеты приходят на маршрутизатор, обрабатываются им, доходят до целевого интерфейса и только на нём обрабатываются. Как правило, списки применяют на входящий трафик (in).

Проверяем связь ПК с сервером ( рис. 9.7 и рис. 9.8).

Create a channel in Teams

Teams are made up of channels, which are the conversations you have with your teammates. Each channel is dedicated to a specific topic, department, or project.

By default, all members of a team can create channels. A standard channel is open for all members and anything posted is searchable by others. If you need a smaller audience for a specific project, you can create a private channel for your team. For a deeper look, see Teams can have standard or private channels.

When you need to create or edit a channel, use the steps below.

Create a standard channel

To create a standard channel, start in the team list. Find the team name and click More options > Add channel. You can also click Manage team, and add a channel in the Channels tab.

You can create up to 200 channels over the life of a team. That number includes channels you create and later delete.

Create a private channel

If you want a focused place to discuss sensitive information such as budgets, resourcing, strategic positioning and so on, create a private channel for your team. Only owners or members of the private channel can access it. To understand who can view what in a private channel, see Private channels in Teams.

You can create up to 30 private channels over the life of a team.

Note: Your admin can change this permission and limit private channel creation to certain roles.

To create a private channel for a team:

Go to the team you want to create the private channel for and choose More options > Add channel.

Enter a name and description for your channel.

Under Privacy, select the down arrow on the right, and then select Private – Accessible only to a specific group of people within the team.

Select Add. This adds a private channel to the team.

Add members to a private channel

As a private channel owner, you can add or remove members, and edit private channel settings. Each person that you add must first be a member of the team.

To add members of your team to a private channel:

Next to the private channel name, select More options > Add members.

Use the Members and Settings tabs to add or remove members and assign roles. Your private channel can have multiple owners and up to 250 members.

When you’re ready, select Done. Members can now post messages in the private channel.

Manage private channel creation

As a team owner, you can turn on or turn off the ability for members to create channels. To see and change this option, go to the Settings tab for the team.

Edit, delete, hide, or leave a channel

Select More options next to the channel name. Then, use the menu to edit, delete, hide, or leave the channel as desired.

Note: Team owners get to decide which team members can delete channels.

Keep in mind that once you delete a channel, you also lose its entire conversation history. However, the OneNote sections associated with that channel will still show up on your team’s SharePoint site.

Teams are made up of channels, which are the conversations you have with your teammates. Each channel is dedicated to a specific topic, department, or project.

Teams can have standard or private channels. When you need to create one, use the steps below.

Create a standard channel

A standard channel is open for all members and anything posted is searchable by others. You don’t add members to a standard channel because the team has access.

Tap Teams , go to the team name, and tap More options > Manage channels.

Tap Add and enter a name and description (optional). This adds a standard channel to the team.

You can create up to 200 channels over the life of a team. That number includes channels you create and later delete.

Create a private channel and add members

Only those users who are owners or members of the private channel can access the channel. To understand who can view what in a private channel, see Private channels in Teams.

You can create up to 30 private channels over the life of a team.

To create a private channel and add members in Teams:

Tap Teams , go to the team name and tap More options > Manage channels.

Tap Add in the header and enter a name and description (optional).

Tap Privacy and then Private as shown.

Tap the back button

Under Add members, type a name in the Add field, and then tap Done.

Your private channel can have multiple owners and up to 250 members.

Edit, delete, hide, or leave a channel

Select More options next to the channel name. Then, use the menu to edit, delete, hide, or leave the channel as desired.

What’s new in Channels 2?¶

Channels 1 and Channels 2 are substantially different codebases, and the upgrade is a major one. While we have attempted to keep things as familiar and backwards-compatible as possible, major architectural shifts mean you will need at least some code changes to upgrade.

Requirements¶

First of all, Channels 2 is Python 3.5 and up only.

If you are using Python 2, or a previous version of Python 3, you cannot use Channels 2 as it relies on the asyncio library and native Python async support. This decision was a tough one, but ultimately Channels is a library built around async functionality and so to not use these features would be foolish in the long run.

Читать еще:  Практическая работа создание бд в access

Apart from that, there are no major changed requirements, and in fact Channels 2 deploys do not need separate worker and server processes and so should be easier to manage.

Conceptual Changes¶

The fundamental layout and concepts of how Channels work have been significantly changed; you’ll need to understand how and why to help in upgrading.

Channel Layers and Processes¶

Channels 1 terminated HTTP and WebSocket connections in a separate process to the one that ran Django code, and shuffled requests and events between them over a cross-process channel layer, based on Redis or similar.

This not only meant that all request data had to be re-serialized over the network, but that you needed to deploy and scale two separate sets of servers. Channels 2 changes this by running the Django code in-process via a threadpool, meaning that the network termination and application logic are combined, like WSGI.

Application Instances¶

Because of this, all processing for a socket happens in the same process, so ASGI applications are now instantiated once per socket and can use local variables on self to store information, rather than the channel_session storage provided before (that is now gone entirely).

The channel layer is now only used to communicate between processes for things like broadcast messaging — in particular, you can talk to other application instances in direct events, rather than having to send directly to client sockets.

This means, for example, to broadcast a chat message, you would now send a new-chat-message event to every application instance that needed it, and the application code can handle that event, serialize the message down to the socket format, and send it out (and apply things like multiplexing).

New Consumers¶

Because of these changes, the way consumers work has also significantly changed. Channels 2 is now a turtles-all-the-way-down design; every aspect of the system is designed as a valid ASGI application, including consumers and the routing system.

The consumer base classes have changed, though if you were using the generic consumers before, the way they work is broadly similar. However, the way that user authentication, sessions, multiplexing, and similar features work has changed.

Full Async¶

Channels 2 is also built on a fundamental async foundation, and all servers are actually running an asynchronous event loop and only jumping to synchronous code when you interact with the Django view system or ORM. That means that you, too, can write fully asynchronous code if you wish.

It’s not a requirement, but it’s there if you need it. We also provide convenience methods that let you jump between synchronous and asynchronous worlds easily, with correct blocking semantics, so you can write most of a consumer in an async style and then have one method that calls the Django ORM run synchronously.

Removed Components¶

The binding framework has been removed entirely — it was a simplistic implementation, and it being in the core package prevented people from exploring their own solutions. It’s likely similar concepts and APIs will appear in a third-party (non-official-Django) package as an option for those who want them.

How to Upgrade¶

While this is not an exhaustive guide, here are some rough rules on how to proceed with an upgrade.

Given the major changes to the architecture and layout of Channels 2, it is likely that upgrading will be a significant rewrite of your code, depending on what you are doing.

It is not a drop-in replacement; we would have done this if we could, but changing to asyncio and Python 3 made it almost impossible to keep things backwards-compatible, and we wanted to correct some major design decisions.

Function-based consumers and Routing¶

Channels 1 allowed you to route by event type (e.g. websocket.connect ) and pass individual functions with routing that looked like this:

And function-based consumers that looked like this:

You’ll need to convert these to be class-based consumers, as routing is now done once, at connection time, and so all the event handlers have to be together in a single ASGI application. In addition, URL arguments are no longer passed down into the individual functions — instead, they will be provided in scope as the key url_route , a dict with an args key containing a list of positional regex groups and a kwargs key with a dict of the named groups.

Routing is also now the main entry point, so you will need to change routing to have a ProtocolTypeRouter with URLRouters nested inside it. See Routing for more.

channel_session and enforce_ordering¶

Any use of the channel_session or enforce_ordering decorators can be removed; ordering is now always followed as protocols are handled in the same process, and channel_session is not needed as the same application instance now handles all traffic from a single client.

Anywhere you stored information in the channel_session can be replaced by storing it on self inside a consumer.

HTTP sessions and Django auth¶

All authentication and sessions are now done with middleware. You can remove any decorators that handled them, like http_session , channel_session_user and so on (in fact, there are no decorators in Channels 2 — it’s all middleware).

To get auth now, wrap your URLRouter in an AuthMiddlewareStack :

You need to replace accesses to message.http_session with self.scope[«session»] , and message.user with self.scope[«user»] . There is no need to do a handoff like channel_session_user_from_http any more — just wrap the auth middleware around and the user will be in the scope for the lifetime of the connection.

Channel Layers¶

Channel layers are now an optional part of Channels, and the interface they need to provide has changed to be async. Only channels_redis , formerly known as asgi_redis , has been updated to match so far.

Читать еще:  Access транскрипция на русском

Settings are still similar to before, but there is no longer a ROUTING key (the base routing is instead defined with ASGI_APPLICATION ):

All consumers have a self.channel_layer and self.channel_name object that is populated if you’ve configured a channel layer. Any messages you send to the channel_name will now go to the consumer rather than directly to the client — see the Channel Layers documentation for more.

The method names are largely the same, but they’re all now awaitables rather than synchronous functions, and send_group is now group_send .

Group objects¶

Group objects no longer exist; instead you should use the group_add , group_discard , and group_send methods on the self.channel_layer object inside of a consumer directly. As an example:

Delay server¶

If you used the delay server before to put things on hold for a few seconds, you can now instead use an AsyncConsumer and asyncio.sleep :

Testing¶

The testing framework has been entirely rewritten to be async-based.

While this does make writing tests a lot easier and cleaner, it means you must entirely rewrite any consumer tests completely — there is no backwards-compatible interface with the old testing client as it was synchronous. You can read more about the new testing framework in the testing documentation .

Also of note is that the live test case class has been renamed from ChannelLiveServerTestCase to ChannelsLiveServerTestCase — note the extra s .

Exception Handling¶

Because the code that’s handling a socket is now in the same process as the socket itself, Channels 2 implements cleaner exception handling than before — if your application raises an unhandled error, it will close the connection (HTTP or WebSocket in the case of Daphne) and log the error to console.

Additionally, sending malformed messages down to the client is now caught and raises exceptions where you’re sending, rather than silently failing and logging to the server console.

© Copyright 2018, Django Software Foundation Revision 69363a22 .

Access — перевод, произношение, транскрипция

существительное ↓

глагол

Мои примеры

Словосочетания

Воспользуйтесь поиском для того, чтобы найти нужное словосочетание, или посмотрите все.

Примеры

Do you have access to the Internet?

У вас есть доступ в интернет? ☰

He always has access to the Prime Minister.

У него всегда есть доступ к премьер-министру. ☰

You’ll need a password to access the database.

Для доступа к базе данных вам понадобится пароль. ☰

We have Internet access at the library.

В нашей библиотеке есть доступ к Интернету. ☰

I had unrestricted access.

У меня был неограниченный доступ. ☰

The word “access” is spelled with two cs.

Слово «access» (доступ) пишется с двумя буквами «с». ☰

That access of fear loosened his joints.

Приступ страха ослабил его мускулы. ☰

She still had access to the Emperor whenever she desired.

Она по-прежнему могла входить к императору в любое время, когда ей этого хотелось. ☰

He gained access to the building.

Он получил доступ к зданию. ☰

My ex-wife deliberately sabotages my access to the children.

Моя бывшая жена умышленно срывает мои свидания с детьми. ☰

The system enables students to access class materials online.

Данная система позволяет студентам получить доступ к материалам занятий в Интернете. ☰

The agreement was needed for use of the access routes to the city.

Данное соглашение требовалось для использования подъездных путей к городу. ☰

You can access our homepage via the Internet.

К нашей домашней странице можно подключиться через интернет. ☰

This report can be accessed via the Internet at www.

Доступ к этому отчёту можно получить через интернет по адресу www… ☰

They paid a premium for access to water.

За доступ к воде они заплатили дополнительно. ☰

Users can access their voice mail remotely.

Пользователи могут получать доступ к своей голосовой почте удалённо. ☰

My ex-husband has access to the children once a week.

Мой бывший муж имеет право видеться с детьми один раз в неделю. ☰

Hackers had illegally accessed information on more than 310,000 consumers.

Хакеры получили незаконный доступ к информации о более чем 310000 потребителях. ☰

We cannot provide you with Internet access unless you agree to these terms.

Мы не можем предоставить вам доступ в интернет, если вы не согласитесь с данными условиями. ☰

She had privileged access to the files.

У неё был особый доступ к этим материалам. ☰

an urban underclass, who have limited access to health care

городская беднота, которая имеет ограниченный доступ к медицинской помощи ☰

Access to the site is closely controlled.

Доступ к сайту тщательно контролируется. ☰

How does one access the attic in this house?

Как попасть на чердак в этом доме? ☰

The theatre has good access for the disabled.

В театре имеется удобный доступ для инвалидов. ☰

We’re trying to improve access for disabled visitors.

Мы пытаемся улучшить доступ для посетителей с ограниченными физическими возможностями. ☰

Nesting places on the cliffs are difficult of access.

Гнездовья на скалах труднодоступны. ☰

This card allows you to access your money at the touch of a button.

Эта карта позволяет вам одним нажатием кнопки получить доступ к своим деньгам. ☰

They have access to up-to-date information through a computer database.

У них есть доступ к новейшей информации через компьютерную базу данных. ☰

In May 1949, Stalin conceded defeat and reopened land access to Berlin.

В мае 1949 года Сталин признал поражение, и вновь открыл наземный доступ к Берлину. ☰

Only employees have access to bank records.

Доступ к банковской документации есть только у сотрудников. ☰

Примеры, ожидающие перевода

. vested the power to access their retirement accounts with their attorney.

she thinks she has no soul, no interior life, but the truth is that she has no access to it

The company provides cheap Internet access. In addition, it makes shareware freely available.

Для того чтобы добавить вариант перевода, кликните по иконке ☰ , напротив примера.

Ссылка на основную публикацию
Adblock
detector