Telos Zephyr Xstream User Manual page 167

Adtran
901 Explorer Ave
Huntsville, AL 35806
800‐827‐0807
www.adtran.com
Adtran makes all sort of equipment for the telecom industry. The Telcos buy equipment from
Adtran. Reputable company. Most USA Telos Dealers carry Adtran equipment.
An appropriate CSU/DSU (Channel Service Unit/Data Service Unit) is required to interconnect
the line with the Zephyr Xstream. Dialing is performed using the CSU/DSU directly. Popular
models are the Adtran DSU III S4W (for 4 wire circuits, Adtran part # 1202013L1) and DSU III
S2W (for 2 wire circuits, Adtran part # 1200015L2) see www.adtran.com or your Adtran dealer.
Adtran also makes CSU/DSU's for use with dedicated 56 or 64kbps circuits. See below.
If the location with Switched 56 is only to be used temporarily, you might wish to rent the
CSU/DSU rather than purchase one. One rental source is:
Silver Lake Audio
90 South Long Beach Rd
Rockville Centre, NY 11570
516‐763‐1776
www.silverlakeaudio.com
In most areas, switched 56 and ISDN are "inter‐worked" within the Central Office switches, so
that subscribers of both services can connect to each other (at a 56kbps rate, of course).
Therefore, the far end unit may be on ISDN or Switched 56.
If two Switched 56 circuits are available (as well as two CSU/DSU's) Stereo or Mono 128
operation is possible.
T1 Circuits
This permits subscriber access to up to 24 channels of 64kbps each. T1 circuits into the dial up
network are frequently used with private telephone systems (i.e. PBXs). However, dedicated T1
service between two locations is available. This option has become increasingly popular for
STLs.
T1 requires a special Multiplexer or DSU (available from Adtran and others) to break out the
individual channels. These are usually modular, permitting each channel (time slot) to be used
individually as desired.
Each Zephyr Xstream would require 1 or 2 channels for bi‐directional mono and stereo,
respectively, if the V.35 split mode were used. In that case, each channel would be broken out
by the multiplexer into a separate V.35/X.21 port.
Or a single 112, 128, 256, 0r 384 kbps connection can be used, if the Xstream V.35 single is
selected for the Interface in the TEL menu. See Appendix 6 (Special Operational Modes) for
more on V.35 Single operation.
USER'S MANUAL
Section 9: The V.35/X.21 Interface Option 155