The Admin Tool is used by station administrators to set up basic station information and to tune station performance.

This chapter covers:

• Setting up station information
• Setting the station’s audio and video parameters
• Setting network parameters

The Admin Tool provides a straightforward interface for setting up a station’s defaults and for tuning audio, video, and network parameters in order to best utilize your network and hardware.

The Admin Tool provides an interface for making changes in the INTV! station’s configuration file, /etc/insoft/INTVStation.ini. Rather than requiring the user to edit the file and make changes, changes made in the Admin Tool are automatically applied to this file.

It is important to remember that if you are not going to be running the Admin Tool from the root account, the account that will be used should have write permission for the configuration file. If the user running the Admin Tool does not have write permission for the file /etc/insoft/INTVStation.ini, they will not be able to run the Admin Tool.

The Admin Tool uses a text-based interface with hierarchical menus. Since the Admin Tool is text-based, it can be used remotely by connecting via rlogin or telnet, which enables the administrator to make adjustments on the server from an offsite location, or to run the server on a workstation without a monitor.

The Admin Tool is split into several submenus. They include:

• Set Channel Info
• Set Video Parameters
• Set Audio Parameters
• Set Network Parameters
• Show Settings
• Manual Override
• Shut Down Station

Each of the submenus will be covered in detail in its own section.

On all submenus, you can enter "M" to return to the Main menu, and "U" to move up a menu. When changing settings that provide a menu of possible choices, the current setting will be denoted with a *. Menu options that require the user to enter a value show the current value, the maximum value, and the minimum value. The Admin Tool will not allow the user to enter an invalid value for any setting.

The channel information identifies your station to the viewers on the network. The three ways your station is identified are the channel number, the channel’s call letters, and the channel description. There can be several stations with the same call letters and/or description, but each channel must have a unique number. The channel number you choose also determines which network port your station broadcasts on. If you use the default station number, it is derived from the station’s IP address so that no two stations on the network ever have the same channel number, and therefore do not broadcast on the same port.

A station’s channel number is its unique identifier on the network. It can be set to any value from 1 to 500. The station’s number cannot be set while the station is sending data, nor can it be set to the same value as another station on the network. Other than that, the number can be chosen arbitrarily.

The channel description is a brief field that can be used to describe the station. It is displayed on the viewer’s Media Chooser along with the station’s call letters and number, and must be less than 50 characters long.

A channel’s call letters are yet another means of identifying the station. The call letters can be four characters or less, and are displayed on the Media Chooser with the description and station number. They are notable because they are displayed on the title bar of the station’s video window when a viewer tunes in the station.

Remember that ideally the station’s call letters and description should give the user a good idea of the content of the station when they see the station list on the Media Chooser.

Administrators can also set a message that users see when they select the Get Info option for the channel. The message that the users receive should be stored in a normal text file in the /etc/insoft directory. The file should be named motd.<channel number>. For example, the Message of the Day file for channel 64 would be:

/etc/insoft/motd.64

The Set Video Parameters option provides the administrator with a set of tools used to properly configure the video settings and to tune the station’s video speed, quality, and bandwidth usage. It also enables the administrator to configure various settings specific to particular video boards. This section discusses the settings available to the administrator. The chapter "Tuning Station Performance" discusses the manipulation of settings to optimize your station’s performance in detail.

Set Frame Size enables you to select the size of the video window that the viewers receive. It is selectable between sixteenth (160x120), quarter (320x240) and full size (640x480) windows. The frame size being sent has a large impact on the amount of bandwidth that the video stream uses, as well as the system resources that the viewers consume.

Set Frame Rate allows you to set the number of frames per second that the station sends out. This can be set between 1 and 30, which is the maximum speed for NTSC full motion video. The amount of frames per second that the viewers can effectively receive depends upon frame size, network bandwidth available, and the hardware that the viewer is running.

TTL is short for "Time To Live", which is basically defined as the number of network routers that each packet can pass through before they are discarded. The default value of 16 should be acceptable for almost every situation. A detailed description of TTL and this setting can be found in Appendix A, "Technical Issues".

This setting determines whether your station broadcasts video when tuned in.

Set Compression allows you to choose the compression/decompression algorithm you wish your outgoing video to use. The video compression setting cannot be changed when the station is sending video data. The compression/decompression algorithms available to the Station are CellB, JPEG, and H.261. The compression/decompression algorithm should be chosen based on the type of video hardware that the station and the viewers have. Note that H.261 compression is available only to Hewlett-Packard DVC users.

Set Board allows you to select the video capture board that you wish to use. INTV! automatically determines which video capture boards are present in the computer, and gives you a list of choices.

Choosing Set Board Specific Parameters enables you to configure the options specific to the video capture board that you have chosen to use. To find information on the configuration options for your video board, consult the documentation supplied with your video capture board.

The Set Audio Options menu is used to configure the station’s outgoing audio stream. While audio generally does not have a large effect on overall network performance or machine performance, proper configuration of the audio settings is the key to sound quality. This section briefly lays out the available audio settings. For detailed discussion of using these settings to tune audio performance, see the chapter entitled "Tuning Station Performance".

TTL is short for "Time To Live", which is basically defined as the number of network routers that each packet can pass through before they are discarded. The default value of 16 should be acceptable for almost every situation. A detailed description of TTL and this setting can be found in Appendix A, "Technical Issues".

This setting determines whether your station broadcasts audio when tuned in.

The Silence Sensor reduces audio traffic by filtering low level background noise. When the audio picked up by the microphone is below a level set by the Silence Sensor, it is filtered and no audio is sent. The Silence Sensor prevents useless audio traffic from consuming network resources. The Silence Sensor accepts a setting between 1 and 100. The danger in setting the audio too high is that useful audio will be filtered along with the background noise. For most applications, the Silence Sensor can be left at a very low level.

This setting determines the level at which you broadcast audio to the viewers. The viewers also have volume controls, so it is best to set the sending volume at a level where you are sure everyone on the network can hear it clearly, and allow the users to determine the level at which they wish to listen.

When you select Set Input Device, the Admin Tool polls your computer and returns a list of potential devices that can be used as an audio input. You can select any input from this list.

The Set Network Parameters menu contains options enabling the administrator to set up INTV! so that it performs well. These settings, combined with the video parameters, determine the amount of bandwidth that INTV! uses and how well it will perform. Proper configuration of these settings is discussed more fully in the chapter "Tuning Station Performance".

If more than one multicast interface is present on the system that the station is running on, this option notifies you and allows you to select between them.

In order to prevent the unnecessary consumption of network bandwidth, INTV! transmits only data when a station is tuned in. Once a viewer has tuned in the station, it periodically sends a "heartbeat" to the station to let it know that the viewer is still tuned in. If the station does not receive a "heartbeat" from a viewer (or a new viewer doesn’t tune in) within the timeout period set using this option, then the station stops broadcasting data. This parameter can be set anywhere between 300 seconds (5 minutes) and 86,400 seconds (24 hours).

If your network has constraints that require you to set a hard ceiling for the amount of bandwidth that INTV! uses, you can specify that limit using the Set Maximum Bandwidth parameter. This setting defaults to 0, which allows INTV! to use as much bandwidth as is required by your video and audio settings. If this is set to a number other than 0, then your framerate is adjusted to ensure that the bandwidth consumption stays below the specified level.

When you select the Show Settings option, INTV! displays a summary of the current settings for your station. The statistics include:

• Current station number, call letters, and description
• Video and audio time-to-live
• The current Silence Sensor and Sending Volume settings
• The current outgoing interface
• The station’s timeout setting
• The maximum bandwidth setting
• If you are sending video, the video size, bandwidth consumption, and frame rate are displayed.
• Statistics are also given regarding the amount of bandwidth audio is consuming.
• Whether video, audio or both are enabled

Manual override is used to start or stop sending video whether users are tuned in or not. It can be used for testing the local viewer (on Parallax equipped machines) if no user is tuned in, or to stop sending both audio and video without shutting down the station. Of course, if someone tunes in the station or a viewer sends a heartbeat, the station will begin sending again.

Also, if you start video manually with no users tuned in, the timeout setting still applies.

You can use this option to shut down the station from within the Admin Tool. You will be asked for confirmation, and if you respond affirmatively, the station will be brought down. It will disappear from all of the station choosers on the network, and anyone tuned in will automatically tune out.

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