In order to receive
audio, there must be either a speaker or a pair of headphones connected
to your computer.
In order to transmit
audio, you must have a microphone plugged into your computer.
It is recommended that
headphones are used in preference to speakers. Using headphones allows
you to listen and talk at the same time (this is known as full duplex audio).
Without the use of headphones the output from the speakers can interfere
with the microphone, causing unpleasant feedback. The only way of avoiding
this is either to use an echo canceller, or to switch to half duplex audio,
which means that you can only speak or listen at any one time, i.e. you
cannot listen to others when you speak, or you cannot speak when you are
listening. This is unnatural and can make conversation difficult.
two ways of starting up RAT:- from the command line and from SDR. Using
SDR is easier as it automatically configures the tool for use.
Using SDR (RECOMMENDED)
- Click on the session advertisement, a box will appear listing the available
tools for the session. Either click on the 'Join' button which will start
all the tools, or click on the tool buttons individually to the left of
From the Command Line
- As with the other Mbone tools the format for setting up RAT from the
command line is as follows:
Prompt> rat [options]
Click on the Start
button in the bottom left hand corner of the screen. Select Run... In the
Run Window, type the following in the open: field.
Open: rat [options]
e.g. for a session
using the address 188.8.131.52, and port 2222 with a ttl of 47, the correct
syntax would be:-
rat -t 47 184.108.40.206/2222
must use the same multicast address and port number in order to talk to
If you can't
hear other people:
Make sure that the left
mute button is not pressed down. When the mute button is pressed down,
the icon (depicting either a speaker, headphones, or the symbol for line
out), will appear inside a grey box, and the audio will be muted.
Make sure that someone
is actually talking. You can see that someone is talking when the left
power meter in the RAT audio window is going up and down.
Make sure that the volume
of the speaker or headphones is not 0. The volume can be adjusted on the
slider bar next to the left power meter.
Make sure that the button
with the little icon under the left mute button is depicting headsets if
using headsets, and speakers if using speakers. You can change between
headsets, speakers and line-out by clicking on the button with the icon.
(Some audio cards will automatically send audio to headsets if they are
plugged in and speakers if not. In this case, the button will not toggle,
but will always display a speaker)
Check that your headsets
are plugged into the computer correctly.
userguide is available in word7,
format. Please refer to this for more detailed information regarding technical
There is also a RAT
which answers many questions about hardware compatibility and general user
Please consult these
two sources of reference first. If your query still remains unanswered,
please send an email to firstname.lastname@example.org