Juniper CTP2000 Series Hardware Manual page 22

NOTE: You can use the eight port T1/E1 interface module to interconnect digital voice
applications with CESoPSN bundles.
Four-wire audio interfaces with E and M signaling interfaces (4WE&M) are commonly used as trunks
between a central office (CO) and a private branch exchange (PBX). E and M is a type of supervisory line
signaling that uses separate leads, called the "E" (ear) lead and "M" (mouth) lead and are traditionally used
in the telecommunications industry. In 4WE&M signaling, two wires are used to receive and two wires are
used to transmit, incorporating simplex control and differential payload in each channel. Type I, II, and V
signaling is supported.
The 4WE&M interface module consists of a front card and a rear transition module (RTM). Port interfaces
are located on connectors A and B of the RTM. (See
RJ-45 connectors are not used.
Figure 15: CTP2000 4WE&M Module
Figure 16: 4WE&M RTM
Not used
4WEM RTM
CAUTION:
other than those matched to the interface module may result in damage to both the
interface module and the RTM. For example, never install a clock module RTM directly
behind a 4WE&M interface module.
Voice ports can be used only by voice compression bundles (VCOMP) and cannot be used for CTP, SAToP,
or CESoPSN bundles. There is no software configuration of 4WE&M ports. Signaling type is configured
by means of jumpers (see
be mapped to a VCOMP bundle. The bundle configuration specifies the remote destination, the local port
or ports transported by the bundle, voice compression options, as well as other configuration options.
Port signaling LEDs
RJ-21 25-pair connectors
Power to the RTM is supplied from the interface module. Using an RTM
Figure 18 on page 16 and
Figure 15 on page 15 and
Table 1 on page 16). One or more 4WE&M ports can
Figure 16 on page 15.) The
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