Cisco Systems PA-2H manual Attaching a Null Modem Cable

Attaching a Null Modem Cable

Figure 7-1 Connecting HSSI Cables (Front View—PA-2H Shown without Handle)

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				LB/C	1	HSSI
TD	TC	RD	RC
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Rev. B

H10889

HSSI cables

To T3, E3, or SONET DSU

Step 2 Attach the network end of your HSSI cables to your T3, E3, or SONET DSU, or other external HSSI equipment.

This completes the procedure for attaching HSSI cables to the HSSI port adapter. If you require a null modem cable for your HSSI connection, refer to the section “Attaching a Null Modem Cable,” which follows; otherwise, proceed to the “Configuring the HSSI Interfaces” section on page 7-3.

Attaching a Null Modem Cable

This section describes the procedure for attaching null modem cables to HSSI port adapters.

The null modem cable can connect two routers directly back to back. The two routers must be in the same location, and can be two Cisco 7000 series routers, two Cisco 7500 series routers, two Cisco 7200 series routers, two Cisco uBR7200 series routers, or one of each. This setup allows you to verify the operation of the HSSI or to directly link the routers in order to build a larger node. The null modem cable uses the same 50-pin connectors as the HSSI cable, but uses the pinouts listed in Table 1-1 in the “HSSI Null Modem Cable” section on page 1-5.

To connect two routers, attach a null modem cable between an HSSI port on each router. Enable the internal transmit clock in both routers by entering the command hssi internal-clock. All router platforms use the same hssi internal-clockcommand to enable the internal transmit clock on the HSSI.

You define Cisco 7000 series and Cisco 7500 series interfaces by type and physical slot/port adapter/port locations. You define Cisco 7200 series and Cisco uBR7200 series interfaces by type and port adapter slot number/port locations. You define the Catalyst RSM/VIP2 in the Catalyst 5000 family switches by port adapter slot number/port location. (The output of the show interfaces command displays the logical unit number on all supported platforms and the physical slot/port adapter/port location in the Cisco 7000 series and Cisco 7500 series, or the port adapter slot number/port location in the Cisco 7200 series and Cisco uBR7200 series routers and the Catalyst RSM/VIP2.)

7-2PA-2H Dual-Port HSSI Port Adapter Installation and Configuration