Section 24: Connection Setup
T
ieline
T E C H N O L O G Y
Page 223
when you dial from the POTS end, but if you dial a POTS line using an ISDN
line connected to the codec, you will need to set the G.711 algorithm in the
codec before you dial.
24.10.4.
G.722 (For ISDN use)
The
G.722
algorithm is for ISDN use. Audio data is sampled at 16 kHz and
the audio quality provided is 7 kHz in bandwidth. It doesn’t use perceptual
coding and can be used for voice–based broadcasts.
It is possible that when you use this algorithm to connect to a non-
T
ieline
codec, the ’framing’ process (where incoming bit streams are identified and
distinguished for individual decoding) can be unsuccessful when a call is
initiated. This can be solved by turning off the ‘session data’ stream sent by
the Tieline codec. To do this select [Menu] > [Configuration] > [System
Settings] > [Session Data] > [Disable]. Please note that this is a global setting
and will also affect all POTS, and IP connections on the codec.
If you try to connect to a
T
ieline
codec with session data disabled, you will
have to ensure that the connection settings on both codecs are identical
because dialing codec session data normally provides this information to the
remote codec. To avoid this problem, simple re-enable session data [Menu] >
[Configuration] > [System Settings] > [Session Data] > [Enable].
24.10.5.
MP2 Mono (For ISDN/X.21/IP use)
This algorithm is used for the transmission of a mono ISDN signal and will
provide 20 kHz quality audio. Bonded ISDN connections using this algorithm
are only possible with
T
ieline
codecs.
24.10.6.
MP2 Stereo (For ISDN/X.21/IP use)
This algorithm is used for the transmission of a stereo broadcast signal and
will provide 20 kHz quality audio. We recommend using 128 kbps
connections for this algorithm. (Related topic: Sample Rate)
24.10.7.
MP2 J-Stereo (For ISDN/X.21/IP use)
This algorithm employs ‘joint stereo’ techniques. Intensity stereo coding is
used to take advantage of commonality between the left and right signals and
this provides more effective use of connection bandwidth – meaning slightly
better quality signals can be provided.
MP2 J-Stereo
can provide you with
better quality signals than the
MP2 Stereo
algorithm.
We recommend using 128 kbps connections for this algorithm. (Related
topic: Sample Rate)
24.10.8.
MP2 Dual (For ISDN/X.21/IP use)
Normally, when Mono/IFB profiles are used over POTS or ISDN, the two
streams are bonded and bi-directional audio is sent simultaneously over each
channel. MP2 streams cannot be bonded so the
MP2 Dual
algorithm allows
Mono/IFB profiles to send audio via the MPEG layer 2 algorithm. It can also