RoadRunner
U S E R S G U I D E
36
Once in the setup sequence, enter the bit rate, sample rate and line
format. The following parameters are required:
Algorithm:
MPEG Layer 2, CCSN, CCSO, (all MUSICAM
algorithms), MPEG Layer 3 or G.722
Sample Rate:
16, 24, 32 or 48 kHz.
Bit Rate:
56, 64, 112 or 128 kb/s
Line format:
1 line (line 1 or line 2) or 2 line (lines 1 and 2)
G.722 Algo Mode NORMAL, NEWPKI, OLDPKI, or NONE
Encoder Algorithm
(
EAL
) — A detailed discussion of the available
algorithms is found in an earlier section. When operating
independently, the algorithm used can be different for each direction of
transmission.
Encoder Sample Rate
(
ESR
) — The encoder sample rate represents how
many times per second the analog audio is sampled by the A/D
converter. With bit rates of 112 or 128 kb/s, higher sample rates will
result in wider bandwidths. Although lower bandwidths may result, at
lower bit rates, 56 or 64 kb/s, lower sample rates will result in cleaner
audio. We recommend using 32 kHz for MPEG Layer 3 and 24 kHz
sampling for MPEG Layer 2. If G.722 is selected as the algorithm, you
will not be given a choice of sample rates.
Encoder Bit Rate
(
EBR
) — For best results, you should select the
highest bit rate available end-to-end and appropriate to your
application. If G.722 is selected as the algorithm, you will only be given
a choice of 56 or 64 kb/s.
Encoder line format
(
ELI
) — At 56 or 64 kb/s with an internal terminal
adapter or when using the G.722 algorithm, you must use a single line
format. Use the 2-line format when using 112 or 128 kb/s bit rate with
an internal terminal adapter. The two line format requires two
connections be made to the far-end codec; that is, both ISDN ‘B’
channels are used. When connected to two far end codecs
simultaneously, you can switch the return audio between the two units
by changing the decoder Line Format from Line 1 to Line 2. If G.722 is
selected as the algorithm, you will only be given a choice of single line
formats.
G.722 Algo Mode (
CGH
)
—For compatibility with European telephones
manufactured by Philips PKI, there are three modes of operation when
using the G.722 algorithm. Select NORMAL when connecting to a
!
note:
