THE SETUP MENU |
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The codecs in the Z/IP ONE can be put into two broad categories: ACT-capable, and QoS-required. Codecs which support
ACT can change bit rate and buffering in response to network conditions. The codecs we refer to as ‘QoS codecs’ should
only be used on network links with guaranteed quality of service, since their bit rates and buffer depth cannot be changed
after the connection is established. The encoders which support ACT are AAC, AAC-LD, AAC-ELD, and AAC-HE.
The aptX Enhanced codec is available as an optional software license. To use aptX, each Z/IP ONE must have a license to
use the codec. If you would like to evaluate the codec before purchasing it, a demonstration mode is available. Z/IP ONEs
without an aptX license will can use the aptX codec for five minutes. At the end of five minutes, the call will be automat-
ically disconnected. You may preview the codec again after a reboot.The aptX Enhanced codec is available as an optional
software license. To use aptX, each Z/IP ONE must have a license to use the codec. If you would like to evaluate the codec
before purchasing it, a demonstration mode is available. Z/IP ONEs without an aptX license will can use the aptX codec for
five minutes. At the end of five minutes, the call will be automatically disconnected. You may preview the codec again after
a reboot.
♦
Bitrate Maximum
and
Bitrate Minimum
– these parameters allow you to set limits on the range of
bitrates available to the Z/IP ONE’s Agile Connection Technology (ACT) intelligence when adjusting
for various network defects. The wider the range, the greater the flexibility of the encoder to ‘fine tune’
your connection and audio fidelity. Your choice of codec will affect the available range of usable rates.
The more you restrict this range, the more consistent the audio quality will be, but with less ability to
accommodate bad network conditions. For codecs which do not support ACT, the maximum bitrate is
always used.
♦
Maximum Buffer
and
Minimum Buffer
– these two numbers specify the minimum and maximum
decoder buffering. For optimum performance, you should set these to 0ms and Unlimited. Note that if
you change the buffering while a call is in progress, you will be notified that the changes will only take
effect after the call is reconnected. Furthermore, the buffering only applies to MPEG codec modes, but
not to G.711, G.722, or PCM. For codecs which do not support ACT, the maximum buffer setting is used.
The total delay in a transmission will be the algorithmic delay of the codec mode used, plus the current
buffer setting (as determined by these values and the Z/IP ONE’s ACT intelligence).
♦
Layer-2 Payload Type
is used with Real-time Transport Protocol (RTP) audio streams and the MPEG
Layer 2 codec. While many players support the dynamic payload type (96), some require that the
payload is set to MPEG Audio (14). Leave this setting on 96 – Default unless you are having trouble with
this exact scenario.
Please note that the original Zephyr/IP and Z/IP ONEs prior to software version 1.5.0r will only recog-
nize Layer 2 streams using the default, payload type 96. If you attempt to connect to one of these codecs
with a Layer 2 stream using payload type 14, the stream will not be decoded by the older codec. The call
will end as an ‘unclean’ disconnect, since receiver considers the received packets malformed. Due to this,
the Z/IP ONE will display a message informing the user of a network transmission failure.
