Telos ZephyrExpress user manual Compatibility, Between Telos Codecs, With Non-Telos Equipment

Compatibility

Between Telos Codecs

The table below shows which Zephyr or ZephyrExpress transmit and receive modes may operate with each other, the resulting audio bandwidth for each, and information which describes what happens to the audio channels when they are output from the decoder.

Xmt Mode	Rcv Mode	Audio Resp.	Notes:
L3 DUAL (one Line)	L3 MONO	15/20kHz*	Audio appears on both
(Channel A)	(Line 1)		outputs.
L3 DUAL (two Lines to	L3 MONO	15/20kHz*	Audio appears on both
two sites)	(Line 1)		outputs at both sites.
L3 DUAL (two Lines to	L3 STEREO	15/20kHz*	Audio output channels
one site)			correspond to input.
L3 JSTEREO or	L3 STEREO	15/20kHz*	Audio output channels
STEREO			correspond to input.
L2 MONO64	L2	7.8/9.8kHz**	Audio appears on both
			outputs.
L2 MONO128	L2	20kHz	Audio appears on both
(Channel A)			outputs.
L2 JSTEREO	L2	20kHz	Audio output channels
			correspond to input.
L2 DUAL	L2	7.8/9.8kHz**	Audio output channels
			correspond to input.
L2 HALF/24	L2 HALF/24	8.6kHz	Audio appears on both
			outputs.
G.722	G.722	7kHz	Audio output corresponds
			to Line connection.

*Depending upon sampling rate: 15kHz at 32 kHz; 20kHz at 48 kHz.

**Depending upon bitrate: 8kHz at 56kbps; 11kHz at 64kbps.

As well, both transmission bitrate and audio sampling rate must correspond in order for operation to occur.

With Non-Telos Equipment

Layer 2 offers compatibility with the widest variety of non-Telos equipment. ZephyrExpress bitstream is in standard ISO format and may be used to communicate with any codec supporting this standard. In modes which require two ISDN channels, the channel-splitting (IMUX) method becomes an issue. ZephyrExpress supports the CDQ splitting scheme, so it may be used with the codecs from a variety of vendors which support this mode.

CODING 5-15