RoadRunner
U S E R S G U I D E
33
The Session
very session required the same three steps to be performed,
regardless of whether you will be making or receiving the call.
The first step is, of course, negotiating with the far-end user.
Determining what algorithm, bit and sample rates you want to use, and
who will make the call. The next step is configuring your
RoadRunner
,
and the last step is connecting.
This chapter will help you get through these three steps by discussing the
various configurations available, how to implement these configurations,
and finally, how to connect.
Encoder and Decoder Algorithms
Since no single algorithm is ideal for all applications, the
RoadRunner
offers several different algorithm/sample rate/bit rate combinations,
each with advantages and disadvantages. In addition, the full range of
available algorithms insures that your
RoadRunner
can connect with
the widest number of codecs. The table below compares some of the
algorithm/sample rate/bit rate combinations that are available.
Recommended combinations are indicated with a
4
.
Algorithm
Sample
rate
Bit rate
Bandwidth
Delay
Cascade
G.722
16 kHz
56/64 kb/s
7.5 kHz
very low
poor
MUSICAM
24 kHz
56/64 kb/s
10.2 kHz
moderate
good
4
MUSICAM
48 kHz
56/64 kb/s
8.5 kHz
moderate
fair
Chapter
7
E