Table Of Contents
Connecting Cisco DSU/CSU High-Speed WAN Interface Cards
Revised: April 15, 2008, OL-14875-01
This document describes Cisco serial and DSU/CSU high-speed WAN interface cards (HWICs) and how to connect them to a network. It contains the following sections:
For an overview of Cisco interface cards used for Cisco access routers, see the Cisco Interface Cards for Cisco Access Routers document.
T1/FT1 DSU/CSU HWICs
This section describes T1/FT1 data service unit/channel service unit (DSU/CSU) HWICs and how to connect them to a network. It contains the following sections:
The 1-port T1/fractionalized T1 (FT1) DSU/CSU HWIC (HWIC-1DSU-T1) includes an integrated DSU/CSU. The HWIC can be configured for either full T1 services or fractionalized T1 services.
T1/FT1 DSU/CSU HWIC LEDs and Loopback Button
Figure 1 HWIC-1DSU-T1 Front Panel
Table 1 T1/FT1 DSU/CSU HWIC LEDs and Loopback Button
Feature Color Description
Line or loopback state is detected or is manually set by the user.
Remote and local alarm conditions.
Internal DSU/CSU in the HWIC is communicating with another DSU/CSU. This LED is on during normal operation.
Push this button to place the HWIC into loopback mode. The service provider can send a signal to test the connection from your site to the central office switch.
Push this button again to turn off loopback mode.
1 Pushing this button places the HWIC-1DSU-T1 in LINE loopback mode.
The HWIC-1DSU-T1 interface card supports the following Cisco integrated services routers (ISRs):
•Cisco 1841 ISR
•Cisco 2801 ISR
•Cisco 2811 ISR
•Cisco 2821 ISR
•Cisco 2851 ISR
•Cisco 3825 ISR
•Cisco 3845 ISR
Note Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Enabling Wetting Current on T1/FT1 DSU/CSU HWICs
The HWIC-1DSU-T1 interface card supports wetting current. Wetting current is a small amount of electrical current (60 to 140 milliamps) sent from the central office to the card to prevent corrosion of electrical contacts in the card's network connection.
Wetting current may be enabled or disabled by the user. It is controlled by a jumper on connector J2 on the card. Figure 2 shows the J2 connector and the jumper.
Figure 2 Jumper Settings for Controlling Wetting Current on the HWIC-1DSU-T1 Card
The feature is enabled by connecting pins 1 and 2 of the J2 connector with a jumper. It is disabled either by removing the jumper or by connecting pins 2 and 3 of the J2 connector.
The card is shipped with the pins 2 and 3 connected, which disables the wetting current.
Prerequisites for Connecting a T1/FT1 DSU/CSU HWIC to a Network
Before connecting an HWIC to the network, ensure that the HWIC is installed in the router, the equipment is properly grounded, and you have the proper cables for connecting the HWIC to the network. This section describes the preparation necessary for connecting a T1/FT1 DSU/CSU HWIC to the network.
Ensure that the equipment you are working with is properly grounded. For instructions on grounding your HWIC, see the Installing Cisco Interface Cards in Cisco Access Routers document.
Use a straight-through RJ-48C-to-RJ-48C cable to connect a T1/FT1 DSU/CSU HWIC to a network.
Connecting a T1/FT1 DSU/CSU HWIC to a Network
To connect a T1/FT1 DSU/CSU HWIC to a network, follow these steps:
Step 1 Confirm that the router is turned off.
Step 2 Connect one end of the straight-through RJ-48C-to-RJ-48C cable to the RJ-48C port on the T1/FT1 DSU/CSU HWIC.
Step 3 Connect the other end of the cable to the T1 wall jack, as shown in Figure 3.
Figure 3 Connecting the T1/FT1 DSU/CSU HWIC to a T1 Wall Jack
Step 4 Turn on power to the router.
Step 5 Check that the CD LED comes on, which means that the internal DSU/CSU is communicating with the DSU/CSU at the T1 service provider's central office.
Obtaining Documentation, Obtaining Support, and Security Guidelines
For information on obtaining documentation, obtaining support, providing documentation feedback, security guidelines, and also recommended aliases and general Cisco documents, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:
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