AT&T System 25 - Manual (Page 80)

INSTALLATION
Off Premises Metallic (Cable) Connections
The connection between the System 25 and another DS1 interface is in most
cases a T1 line with repeaters. The proper lightning protection must be
provided (as shown in Table 2-B). Figure 2-23 shows a diagram of the off
premise cabling. See the “install CSU” section of this manual for the
installation instructions for the CSU.
* D S X - 1 R E F E R S T O A P H Y S I C A L C R O S S - C O N N E C T F O R D S 1 S I G N A L S
Figure 2-23. DS1 Connections—Off Premise Cabling
Off Premises Non Metallic Connections
Many alternatives to DS1 metallic transmission facilities exist. Some of these
systems include Iightguide (fiber optics), microwave, infrared, and radio
waves. Other type transmission facilities can be used as long as they are
technically compatible and connected via the DS1 cross connect point.
Figure 2-24 shows a block diagram of non metallic cabling transmission
systems.
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