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Cisco 7600 Series Router SIP, SSC, and SPA Hardware Installation Guide
OL-5052-14
Chapter 3 Overview: Cisco 7600 Series Router Shared Port Adapters
4-Port and 8-Port Fast Ethernet SPA Overview
Cables, Connectors, and Pinouts
The interface connectors on the 4-Port and 8-Port Fast Ethernet SPA are four or eight individual RJ-45
receptacles. You can use all interface connectors simultaneously. Each connection supports IEEE 802.3
and Ethernet 10/100BASE-T interfaces compliant with appropriate standards. Cisco Systems does not
supply Category 5 unshielded twisted-pair (UTP) RJ-45 cables; these cables are available commercially.
Figure 3-42
shows the RJ-45 connector.
Table 3-24
lists the pinouts and signals for the RJ-45 connector.
Figure 3-42
RJ-45 Connections, Plug, and Receptacle
Note
Referring to the RJ-45 pinout in
Table 3-24
, proper common-mode line terminations should be used for
the unused Category 5 UTP cable pairs 4/5 and 7/8. Common-mode termination reduces the
contributions to electromagnetic interference (EMI) and susceptibility to common-mode sources. Wire
pairs 4/5 and 7/8 are actively terminated in the RJ-45 port circuitry in the 4-Port and 8-Port Fast Ethernet
SPA.
The 4-Port and 8-Port Fast Ethernet SPA supports automatic MDI/MDIX crossover at all speeds of
operation allowing the SPA to work with straight-through and crossover Ethernet cables. Depending on
your RJ-45 interface cabling requirements, use the pinouts in
Figure 3-43
and
Figure 3-44
.
Figure 3-43
Straight-Through Cable Pinout, RJ-45 Connection to a Hub or Repeater
Table 3-24
RJ-45 Connector Pinout
Pin
Description
1
Transmit data + (TxD+)
2
TxD–
3
Receive data + (RxD+)
6
RxD–
248373
8 7 6 5 4 3 2 1
RJ-45 connector
Hub or LAN switch
Ethernet port
3 TxD+
6 TxD–
1 RxD+
2 RxD–
3 RxD+
6 RxD–
1 TxD+
2 TxD–
H7101