37
time. The default is 60 seconds, but this can be shortened or lengthened as desired. If an indefinite connection is
necessary, refer to
Operating MultiRack in a 24/7 Environment
on
Page 80
for additional information.
Encoder
- It is unnecessary to define any decoder types when using ACCESS because they automatically adapt to
the incoming stream. Using this menu, users can select the encoder used to send audio from this ACCESS (local)
as well as the encoder used to send audio to this ACCESS (remote). The default value of the remote encoder is to
follow the local encoder (i.e., it will send exactly the same codec mode it receives). This is defined as Follow Mode
in the remote encoder selection table. See About the Algorithms section on
Page 86
for more information on
selecting encoders.
Transmit On/Off
- This option determines whether the selected encoder (local or remote) is actually sending
any data. By default, Transmission and Reception on all encoders is turned on, but there may be circumstances
where one-way operation is desired (e.g.
Multistreaming
, as described on
page 89
). Turning off the local encoder
transmission disables
outgoing
audio, and disabling the remote encoder transmission disables
incoming
audio.
ADVANCED LOCAL & REMOTE OPTIONS
The following advanced options apply to both the
local and remote entries, and largely deal with the performance
of
Jitter Buffer Manager
. This is actually a very complex decision-making process involving many variables, and
most of the time the default parameters should work well. These advanced options are a means of overriding the
defaults, and Comrex recommends that users take care when changing them. Note that when it comes to settings
that effect the jitter buffer manager, local settings affect the decoder on the local side, and remote settings affect
the decoder on the remote end.
Frames per Packet
- This function allows the encoder to wait for variable “
X
” number of frames to exist before
sending a packet. This option differs from FEC because each frame is only sent once. Setting this value to a number
higher than one can reduce network usage, at the expense of delay. This is because packet overhead bits like IP and
UDP headers are sent less often.
Decoder Downmix
- This option controls the method by which decoded stereo audio will be down-mixed to mono.
Loss Cushion
- Packets may arrive at the decoder displaying a range of statistical properties. They may arrive in
reasonably good timing and in order, or half may arrive quickly with the other half delayed significantly. In some
cases, most of the packets arrive in a timely manner, but a small percentage of them may be extremely late. It is
usually preferable to allow these late packets to be left out of the stream entirely and keep the delay lower. The
decoder error concealment hides these packet losses. The
Loss Cushion
parameter instructs the buffer manager
to ignore a certain percentage of late packets in its calculation. The default value is 5%. Applications that are not
delay-sensitive may wish to reduce this value to zero, while extremely delay-sensitive applications may prefer to
have this closer to 25%.
Retransmit Squelch Trigger
- Retransmit Squelch options are used to determine how the buffer manager reacts
to typical data dropouts like those seen on wireless networks. The Trigger option Determines the amount of time
the decoder must experience 100% packet loss before the Retransmit Squelch function is triggered. Default is one
second.
Summary of Contents for ACCESS MultiRack
Page 1: ...Product Manual ...
Page 27: ...27 Figure 11 network recovery mode ...
