Telos Zephyr User Manual page 101

CURIOSITY NOTE!
In the old days a CSU (Channel Service Unit) was used to
terminate the digital circuit. One or more DSUs (often in the
form of plug in cards) were used to provide the interface to the
terminal equipment. These days the 2 devices are nearly
always combined and are variously referred to as CSUs,
DSUs, CSU/DSUs, and DSU/CSUs!
Digital Signal Processing. The Zephyr uses DSP to perform the coding
DSP.
and decoding functions. Also refers to a Digital Signal Processor, the actual chips which
perform the processing functions. One or two plug- in DSP card modules may be
installed in the unit giving a total of 5 (2 card version) or 3 (1 card version) DSPs.
One-DSP card/Two-DSP card configuration. Refers to Zephyr configurations.
The "mono" one- DSP card configuration is that which exists when only one DSP card is
installed within the unit (3 DSPs would be present); the "stereo" two- channel
configuration requires two DSP cards (for a total of 5 DSPs). The two- DSP card
configuration also usually needs to have both digital ports connected to a transmission
path. However, the two- channel configuration supports single- channel as a subset. A
full discussion of these issues is to be found in section 11 (Technical Information) and a
review of available Zephyr configurations appears in section 2 (Introduction).
Cables
The Zephyr connects to digital transmission channels via the ports from
HOT TIP!
A "mono" one-DSP card configuration can support 2 bi-
direction audio channels if the G.722 coding mode is used.
HOT TIP!
A mono one-DSP card unit can receive a STEREO signal
using both ports.
the V.35/X.21 interface module.
The cables available from Telos, connect to standard terminal adapters or CSUs, which,
in turn, connect to the digital network channels. The design of the port electronics
permits interface with either V.35 or X.21 equipment – the connector style and pin- out
is the only difference.
Section 6.....NON-ISDN NETWORKS 101