Chapter 3. Installation
63
T1 Cabling Considerations
Connection of the D/I Mux III in channel bank mode to the T1 network is a DTE-to-DCE connection. Some
examples of D/I Mux III-to-DCE connections are: Channel Service Units (CSUs), Smart Jacks, Fiber Optic
Modems, and Fiber Multiplexers. See Table 3-2 for details.
Table 3-2. T1 Connection to Data Communications Equipment (DCE)
D/I Mux
III (DTE)
DB-15
Connector
RJ-48
Connector
Transmission
Direction
DB-15
Connector
RJ-48
Connector
Connectio
n (DCE)
Tip 1 Rx 3 1
⇐
3 1 Tip 1
Ring 1 Rx 11 2
⇐
11 2 Ring 1
Tip Tx 1 4
⇒
1 4 Tip
Ring Tx 9 5
⇒
9 5 Ring
Connection of two D/I Mux III multiplexers in channel bank mode, each communicating with the
other in a point-to-point private network, is a DTE-to-DTE connection. Use Table 3-3 for cabling
information.
When connecting a D/I Mux III in drop-and-insert mode, the T1-1 port typically connects to the T1 network,
and the T1-2 port connects to Data Terminal Equipment (DTE). Some examples of D/I Mux III-to-DTE
connections are: Digital Private Branch Exchanges (T1 PBXs), Channel Banks, and T1 Multiplexers (as
indicated in Table 3-3).
D/I Mux III in dual channel bank mode can be wired to communicate with either DTE or DCE
devices.
Table 3-3. Connection to Data Terminal Equipment (DTE)
D/I Mux III
(DTE)
DB-15
Connector
RJ-48
Connector
Transmission
Direction
DB-15
Connector
RJ-48
Connector
Connectio
n (DTE)
Tip 1 Rx 3 1
⇐
1 4 Tip
Ring 1 Rx 11 2
⇐
9 5 Ring
Tip Tx 1 4
⇒
3 1 Tip 1
Ring Tx 9 5
⇒
11 2 Ring 1