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VNCtalk User Manual


VNCTalk is a specialized application for realtime communication services, which is used via the ''VNCTalk Zimlet'', installed in a Zimbra Collaboration Suite'' environment. The VNCTalk Zimlet provides to the user services as textchat, videoconferencing as well as online document collaboration.

VNCTalk provides the employees of your company the opportunity to interact, communicate & collaborate more efficiently using the Zimbra-UI without installing any additional Software on client side. The only precondition for the users, is a modern Web-Browser, such as Google Chrome, to use VNCTalk to the full extend. The communication between users is, thanks to TLS-encryption, secure as well.

How to activate VNCtalk

The following images illustrate all necessary steps to activate the VNCtalk Zimlet on clientside.

Step 1: Preferences Tab

Open the Preferences tab in the Zimbra Toolbar.

Step 2: Zimlets Menu

Open the Zimlets Menu on the left panel and activate the checkbox VNCtalk Application.

Step 3: Save

Save your preferences by clicking the Save button in the top-left corner.

Step 4: Confirm Reload

Click Yes to reload the application afterwards and the VNCtalk Zimlet becomes available.


Before using VNCtalk for the first time, the system administrator has to configure it by providing all necessary information. Please check the VNCtalk Installation Guide in regards to that matter.

This part only targets users, which want to use an additional, external 3rd party XMPP-client in conjunction with VNCtalk. In case you want to use VNCtalk exclusively via the ZWC, the next paragraph can be ignored.

The VNCtalk priorities can be set as illustrated in the next image.

Note: The highest prioritized xmpp-client will receive the communication events(chat messages, conference invitations, etc.), in case multiple clients are active on the user's clientsystem.

After modifying the priotity values, apply the changes by pressing the OK button.

Note: VNC does not provide any support for 3rd party XMPP-clients.

Individual Settings

The user can modify the VNCtalk preferences to suit its personal needs. The user has the following options:

  • Profile picture: By clicking on the avatar bubble, a file browser window opens, allowing you to select a profile picture as your avatar.
  • My status: Shows the remote contacts the user's current state. The user can select between Available, Away, Busy and Offine. All states are associated with different colors, which are displayed in the contact lists as well.
  • Show Recent: Activate/deactivate to show/hide the list of recent activities in the left panel.
  • Play Sounds: The user can enable or disable the VNCtalk notification sounds on his behalf.
  • Volume: To adjust the volume of the notification sounds.

How to use VNCtalk

Which features does VNCtalk provide?

VNCTalk offers these functionalities to the user:

  1. Chat: 1on1 or in a conference with multiple participants.

  2. Videoconferencing: 1on1 or in a conference with multiple participants.

  3. Filetransfer: Users can exchange files.

  4. Favorite lists: Fast access to frequently used contacts. Favorites can be automatically generated on server side for the user as well.

  5. Contacts: Add & remove contacts to/from Favorites.

When paticipating in a video conference, the user has the following options:

  1. Moderation:

    • The owner of a video conference can mute other participants, kick out participants from the conference as well as securing the conference room against unwanted access by setting a password, for which potential participants are promptend when attempting to join the conference.

    • Participants can disable/re-enable their own microphone and camera at any time.

    Note: Participants muted by the moderator, can only reactivate their microphone by themselves.

    • The Moderator can define the starting conditions(enabled/disabled) for camera & microphone for all users joining the video conference.
  2. Screensharing: Users can show their screens to other participants of the video conference.

    Note: In order to use the screensharing functionality, the user has to install the VNCtalk Desktop Streamer Web-Browser extension, which also requires the whitelisting of the talk server's domain up front.

  3. Realtime document collaboration and editing: Users can work on the same document simultaneously, while every user is associated to a different color. The collaborative documents created this way can be exported to various file formats afterwards.

Where is version information provided?

To gather information and acquire further documentation on the current version of VNCTalk, navigate to the Zimlets section in the left panel of the Zimbra Web-client's Mail tab and click on VNCTalk Zimlet. You will find the version information in the About us tab. Clicking on the rider Configuration allows to

  • set whether the Zimlet should auto login on startup or manually by clicking the Contact list button in the lower right corner of the ZWC.
  • set the Zimlet client's priorities as explained in section Configuration.

How to use the Zimlet

This section provides an overview and a brief description on the VNCTalk tab in the Zimbra Webclient. To access this view, open the VNCTalk tab:

First steps - the interface

The contact list is located on the right side of the VNCTalk window. It opens, when clicking the button in the lower right corner, listing the contacts currently online.
The contact list contains all available users and their status, indicated by the respective colors, as well as your personal favorite list.
When All is selected as display option, offline users are shown as well.


Contacts can be found by opening the tab Contacts and start searching for specific users. The search result list of potential candidates autocompletes as you type.
Chats and video conferences can also be started directly from picking a contact from the search results, without the need of adding it to the favorites first.

Favorite Lists

In case automated contact lists are disabled by server configuration and manual favorite list management is enabled, the user can, for a better overview, assemble a favorite list with individiual groups to add contacts with whom the users frequently communicates.
Every user starts with an empty favorite list, that can be filled up individually with groups and users.
Favorite lists can be filled up

  • by switching from the Favorites tab (star symbol) to the Contacts tab (symbol showing two persons):

    Now search for a contact and add it from the search results to your favorites.

  • directly via the list menu of an existing favorite group, which allows the user to search for and add new contacts directly to that group.

Note: Favorites are not persistent, if automated contact lists are activated. The favorite lists are reset on regular basis in that case, since they are managed by the server.

The group menu on the right side of a favorite group can be used to

  • add contacts to the group
  • rename or delete that group
  • invite all group members to a groupchat or video conference.

Control Panel on the left

The left side control panel contains

  • the button New Chatroom: Opens a dialog window to create a new chat conference.
  • the Recent section, that displays the user's last conversations, no matter if text or video. Clicking on an item in that list, will reopen the respective chat/conference again.
  • the Public Chat Room list: The list of currently open public chatrooms.

Both lists can be hidden by clicking on the arrow symbol.

Right of the New Chatroom button, are two more buttons available:

  • New Call: Opens a dialog window to create a new video conference.
  • More: Allows you to join a group chat or video conference.

Text Chat

Conversation between two users (1:1)

VNCtalk enables the users to perform a 1:1 textchat. When the contact list is closed, the user has the number of favorite list contacts displayed, that are currently online. Clicking on the symbol, opens the contact list, listing the users favorites and their current status. To engage in a chat with another user, a chat window must be opened by clicking on the speech baloon icon or directly on the respective user's name.

In this example, the Favorite List contains two users, one of them online:

Chat history is loaded automatically when opening a chat window:

Text chat conference (1:n)

VNCTalk also allows to engage in 1:n Chats, so called Chat conferences using conference rooms.
There are two types of conference rooms in VNCTalk:

  • Public: These chatrooms are listed in the left panel in section Public Chat Rooms until these are closed by the moderator.
  • Private: Every user can create a private chatroom and invite other users. In case a user knows a private room's title, this user can join the private chatroom, even when he/she has not been invited explicitely, if the private room is not locked by the room's moderator.

Creating a chatroom

Chatrooms can be created by clicking on the button New Chatroom in the top-left corner of the VNCTalk window. This opens the New chat configuration window, where the user can add contacts and set the chatroom specific preferences.

New chat configuration window:

Notification message in the green notification bar, after a chatroom has been created:

Public Chatrooms

Newly created chatrooms are per default set to private. To create a new public chatroom, the switch Hide chatroom from public display must be explicitely deactivated.

Public chatrooms are listed in the left side panel and can be entered by clicking on the respective public chatroom's name.

A public chatroom can also be directly created for a group in the favorite list. Doing so, will invite all groups members to join that chatroom, while the name of the chatroom will be automatically set to the groupname. Rooms created this way are created as public chatrooms.

Private Chatrooms

Private chatrooms are created by clicking the button New Chatroom in the top-left corner of the VNCTalk window. After clicking, the New chat configuration window opens to invite contacts and set the chatroom's preferences.
To create a private room, instead of a public one, the switch Hide chatroom from public display must be set to ''ON'', which is the default setting. Now users who do not know the chatroom's name, are not able to join the room, since private rooms are not publically listed.

To enter a private room without being invited, a user can click on the button More an select Join Groupchat from the opening dropdown menu. Now the user has to enter the name of the particular chatroom he wants to join:

The chatroom is now displayed in the left panel section Recent.
In case the moderator renames the room later on, the new name will be displayed in the Recent list from that moment on.

Video Conferencing

How to start a video conference

There are several ways to start a video conference in VNCTalk:

  • Using the New call functionality
  • out of a text chat
  • out of a group chat

Add participants to a video conference

The New Call functionality is a very comfortable way to start a video conference. To start a video conference, click on the VNCTalk tab in the Zimbra bar at the top of your screen.

Then click on the New Call button to open the configuration window.

Here you can add the participants you want to invite. A list with participant suggestions will unroll after you typed at least four letters of the contact you are looking for. Then you can name your video conference and copy the conference link, for example to invite external users without a Zimbra account.

After clicking the Start video call button, the new video conference opens:

Start a video conference from the text chat or the contact list

There are several ways to start a video conference from a text chat or contact list:

  • start video call via contact list
  • start video call via 1:1 chat
  • start video call via favourite list
  • start video call via 1:n chat.

which are illustrated here:

Option a shows how to start a call from text chat and contact list, while option b shows how to start a conference from group chat or favourite lists.

The invited user will get a green notification bar at the top of his Zimbra Web Client displayed, which he/she can accept or decline. If the user accepts the invitation, the video conference will start.

If the invitation is declined, the owner of the conference is notified about the rejection via chat.

Video conference functionalities

To use the different video conference functionalities, please move your mouse cursor to the upper part of the video conference window. Now the configuration bar becomes visible.

Settings and displays

These menu bars provadie you the ability to change various settings, for example:

  • Language
  • Camera
  • Microphone
  • Audio output

Note: Only the owner of the conference has moderator rights.

On the left side different settings can be selected, e.g. which camera and microphone are used:

The preview images show several details, e.g. who has enabled or disabled microphone or camera, the owner of the conference or the transmission rates:

  • The blue button with the signal strength symbol shows the transmission rates. To show detailed information, the button has to be toggled.
  • The speaker icon indicates the current speaker.
  • The blue dots on the left side of the preview image indicate the microphone's current volume. When the microphone is too quiet, or too far away from the speaker, only one dot is displayed. When the voice is loud and clear, five dots are displayed.
  • The buttons for Microphone and Camera are displayed in the lower left part of the preview window. If someone disables his/her microphone, a crossed out microphone icon is displayed for all users. If a camera is disabled, all users see a crossed out camera icon.
  • The Star on the lower right edge shows the owner of the conference to all users. The person with the star icon has moderators rights and can e.g. kick out people.
  • Clicking the Arrow icon on the right side next to the preview windows can hide or display the preview.

Muting and unmuting the microphone

The sound transmission can be switched on and off at will. To do this, click on the microphone icon in the top menu bar. You and the other attendees of the conference will then see a crossed microphone symbol which indicates that you have deactivated your sound transmission. You can see this by the blue underlined microphone in the upper bar and in the lower right of the preview image. To resume sound transmission, simply click on the icon again.

Switch video transmission on / off

Like the microphone, you can also turn the camera on and off. Again, a deactivated device with a blue underlined symbol is shown as well as in the preview image with a crossed camera:

Document Collaboration (Etherpad)

VNCTalk provides a web-based, collaborative real-time text editor based on Etherpad. It can be opened by using the Shared Document button in the configuration bar.

After you have opened the document editor, you can switch between the editor and the video conference by repeatedly clicking the shared document button. You can also see the users connected to the conference on the right hand side of the shared document's contact list.
A text color is assigned to each of these participants in order to be able to assign the text modules to the respective participant. The text color can be changed in the upper right corner by clicking on the user symbol:

All participants can now edit the document in real time. The known formatting options (for example, italic, bold, etc.) are available:

The Etherpad also allows to import files or to export the current document to different file types.


The Screensharing funtionality allows you to show your desktop content, from a single application window up to your complete desktop, to the current conference participants.

Note: For screen sharing your browser requires the plugin VNCtalk Desktop Streamer

To share your screen, click the Share Screen button in the settings bar:

You have the option to decide which part of your screen you want to share with the conference participants: You can share the entire screen as well as individual application windows:

After you have shared the screen, the conference attendees can see the part of your screen that you have shared:

To end the screen sharing, click on Stop sharing at the lower edge of your conference screen.

Full screen

In VNCtalk you can also extend the current conference to your whole screen. The Full screen button is located on the right side of the settings bar:

To exit Full screen mode, press the ESC key on your keyboard or the button in the top menu bar:

Show and hide participants

The button for opening and closing the participant list is located at the upper left edge.

Change your own display name

Users can change their own name displayed in the conference:
Click on your name in the middle of the preview window to change your display name.

Moderator Rights

The current owner of a conference has more rights than the other participants.
The owner of the conference is indicated by a small star symbol in the lower right corner of the video preview. The moderator's rights include:

  • The blocking of a conference for further participants by setting a password
  • Muting other participants
  • The possibility to use the kickout functionality to remove selected participants from the conference

The asterisk symbol indicates the owner of the conference:

Startup settings

The leader of the conference has moderator rights and can determine whether the attendees enter the conference with the microphone deactivated and / or the camera deactivated. This decision can be reversed later:

Follow me

Usually the camera participants rotate in the conference, placing always the current speaker on the big screen.
The Follow Me function permanently sets the conference manager to the large picture and all other participants remain in the preview mode.

Lock / unlock the conference room

This function makes it is possible to provide the room with a password and thus prevent others from accessing the video conference.
To do this, click on the Share Link button and set a password in the window that has opened; Then click Add:

If you have set the password, you can end the dialogue.
You can also remove the password in this settings window later on if you like.
When you have confirmed the new password, you can close the dialog box using Done.

After clicking Done the room is locked and is displayed to you as a locked room.

Users who want to join the video conference now get prompted to enter a password. A notification will appear if the password entered is incorrect:


The conference owner can remove other users from the conference by clicking on the Kick out button. This button can be found in the upper right corner of the user's video preview:


With the Mute button the owner of the conference can disable other user's microphones.
The moderator himself can not reactivate the microphone of the participant muted by the moderator or participants who have already deactivated their microphone themselves.

File Transfer

VNCTalk allows its users to exchange files. It is possible to send a file in the 1:1 textchat as well as from a 1:n textchat conference to all participating users.

Sending files

Start a 1:1 textchat and click on the paperclip icon:

Locate the desired file in the dialog box and click Open:

A notification dialogue appears in the chat window, informing you about the start and progress of the file transfer:

Receiving files

Other users can send files to you. In that case, you will be notified in your Zimbra user interface by a green message bar:

Depending on the browser settings, if a default download location has been specified you are not prompted here.

When the file transfer has been completed successfully, the user is also notified:

Note: The Save to VNCsafe option is only available if the VNCsafe-zimlet has been activated and configured for the respective account.


An optional feature for VNCtalk is the Whiteboard.
Like the collaborative real-time Etherpad based text editor described, the Whiteboard is a collaborative tool as well, where every participant of the whiteboard-attached chat/chatroom can perform actions, which are displayed to all other participants in real time.

Install the Whiteboard feature for VNCtalk

Login to your VNCtalk-backend server via ssh and install the Whiteboard extension:

$ sudo apt-get update
$ sudo apt-get dist-upgrade
$ apt-get install vnc-whiteboard

Once the installation has been finished, reboot the VNCtalk-backend-server.

Now update the Zimlet to the latest version to get the Whiteboard support in Zimbra: Login to your Zimbra-Mailbox server(s) via ssh and update the Zimlet by executing:

$ sudo su - zimbra
$ zm-apt-get update
$ zm-apt-get upgrade

When completed, restart the mailbox and flush caches to apply:

$ zmmailboxdctl restart && zmprov fc all

The VNCtalk Zimlet supports the Whiteboard extension for Zimlet version and above.
To check the currently installed version on your mailbox(es), execute as user zimbra:

$ zmpkg list | grep zcs-vnc-talk
ii  zcs-vnc-talk      all          Chat application for zimbra.

Activate the Whiteboard feature for VNCtalk

To activate the Whiteboard, you have to set the Whiteboard-URL in the VNCtalk Zimlet's admin configuration:

  1. Open Zimbra Admin interface as the Zimbra-admin, then navigate to the section Configure -> VNCtalk Zimlet. This opens the VNCtalk global configuration section.
  2. In section Basic XMPP configuration
    • Enter the Whiteboard URL: The Whiteboard-URL composes of your talk-backend-server's URL and Port 444, for example: https://talk.yourdomain.tld:444
    • Click the Save button in the top-right corner to apply the changes made.

How to use the Whiteboard

Once the Whiteboard has been activated in the Zimbra Admin-UI, it will become available for all VNCtalk users, indicated by the new Icon displayed. The Whiteboard is available for 1on1 chats as well as for groupchats:

1on1 chats group chats

When opening the Whiteboard for a 1on1 chat or chatroom by clicking the icon, the respective chat window is replaced by the whiteboard interface for that user, resizing the chat window to the full extend of the VNCtalk frame.

Note: As long as the Whiteboard interface is open, the window can only be minimized or extended to fullscreen, but not resized anymore.

To switch back to chat mode, click on the speech bubble icon:

Back in chat mode, the resize button becomes available again, which when clicked, will resize the chat window back to its original state:

The Whiteboard interface

The left panel of the Whiteboard interface contains the toolbox, containing all Whiteboard functions, described in this section.

Basic Elements

Tag Function Usage
1 Pen & Lines Draw freely using the pen, draw straight lines and arrows.
2 Shapes Draw different shapes: squares, triangles, circles & ellipses.
3 Text Add a text field: Select font color & size, make text bold or italic or both.
4 Graph Define a grid for drawing graphs. Four different granularities are available.

Selecting and Coloring

Tag Function Usage
5 Select Select an item in the Whiteboard by clicking on it once: A thin dashed red line will envelop the item now, indicating that it is now selected. Now perform operations on it like Delete or move it around via drag & drop.

Note: Select is the default operation, if no other operation is selected in the toolbox.
6 Background Select the backgroud color out of twenty pre-defined colors. (As an example, blue is selected as background color in the image above)
7 Pen Color Select the color of the pen out of thirty pre-defined colors.
8 Pen Width Select pen's thickness out of five pre-defined sizes

Image import and fullscreen mode

Import images & resize the Whiteboard to fullscreen

Tag Function Usage
9 Import Image Import an image: When this icon in the toolbox is clicked, your file manager will open, prompting you to select an image to import.

Note: The image will be imported in full size. Therefore adjust the resolution of the respective image to fit the Whiteboard before importing it.
10 View/Exit fullscreen Hovering the mouse pointer in the Whiteboard will slide in the View/ Exit Fullscreen button, which on click will resize the Whiteboard to fullscreen.
Clicking the button in fullscreen again, will return to the previous size in the frame.

Delete- & cleanup operations

Tag Function Usage
11 Eraser, Delete & Clear Explained up-down: Eraser: When selected, the mouse cursor becomes an Eraser, which will clear previously painted objects on mouse over while pressing the left mouse button (LMB). Delete: This tool deletes the currently selected item. When no item is selected, this button is without function. Clear: This button cleans up the whole Whiteboard sheet on a single click, so take care!
12 Undo & Redo Clicking on the Icon in the toolbox will open a sub-menu containing another two icons, where 1) the upper icon undo reverts the last operation on click ans 2) the lower icon redo re-applies the last undone operation on click.
13 Create another Whiteboard sheet Clicking the + button right of the current Whiteboard tab will ceate and open another empty whiteboard sheet to work on. To switch between multiple sheets, click on the respective tab descriptor Whiteboard-id of the sheet you want to switch to.
14 Close & erase sheet Click on the x in the respective Whiteboard tab descriptor to close & purge a sheet.

Note: You will be prompted if you are really sure, since when approving with Yes: The sheet will be gone for good. Of course the undo operation applies here as well. Please also note, that unclosed sheets in chats will stay there until one of the participants closes them off.

Close an existing Whiteboard sheet: