Cisco 1805 DOCSIS Cable Router Hardware Installation Guide
Cable Connection Procedures for Cisco 1805 DOCSIS Cable Router
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Cable Information and Specifications for Cisco 1805 DOCSIS Cable Routers

Table Of Contents

Cable Information and Specifications for
Cisco 1805 DOCSIS Cable Routers

Console and Auxiliary Port Considerations

Console Port Connections

Auxiliary Port Connections

Preparing to Connect to a Network

Ethernet Connections

Serial DTE or DCE Devices

Signaling Standards Supported

Distance Limitations

Asynchronous/Synchronous Serial Module Baud Rates


Cable Information and Specifications for
Cisco 1805 DOCSIS Cable Routers


This document gives cable information and specifications for the console port, auxiliary port, and network ports on your Cisco 1805 DOCSIS cable router. It contains the following sections:

Console and Auxiliary Port Considerations

Preparing to Connect to a Network

For cable connection procedures, see the "Cable Connection Procedures for Cisco 1805 DOCSIS Cable Router" document.

Console and Auxiliary Port Considerations

The router includes an asynchronous serial console port and an auxiliary port. The console and auxiliary ports provide access to the router either locally using a console terminal connected to the console port, or remotely, using a modem connected to the auxiliary port. This section provides important cabling information to consider before connecting the router to a console terminal or modem.

The main difference between the console and auxiliary ports is that the auxiliary port supports flow control, whereas the console port does not. Flow control paces the transmission of data between a sending device and a receiving device. Flow control ensures that the receiving device can absorb the data sent to it before the sending device sends more. When the buffers on the receiving device are full, a message is sent to the sending device to suspend transmission until the data in the buffers has been processed. Because the auxiliary port supports flow control, it is ideally suited for use with the high-speed transmissions of a modem. Console terminals send data at slower speeds than modems; therefore, the console port is ideally suited for use with console terminals.

Console Port Connections

The router has an EIA/TIA-232 asynchronous serial console port (RJ-45). Depending on the cable and the adapter used, this port will appear as a data terminal equipment (DTE) or data communications equipment (DCE) device at the end of the cable.

For connection to a PC running terminal emulation software, your router is provided with an RJ-45-to-DB-9 cable.

To connect the router to an ASCII terminal, use the RJ-45-to-DB-9 cable and a DB-9-to-DB-25 adapter (provided).

The default parameters for the console port are 9600 baud, 8 data bits, no bparity, and 1 stop bit. The console port does not support mode control. For detailed information about installing a console terminal, see the "Connecting to a Console Terminal or Modem" section on page 5-3.

For cable and port pinouts, see the Cisco Modular Access Router Cable Specifications document located on Cisco.com.

Auxiliary Port Connections

The router has an EIA/TIA-232 asynchronous serial auxiliary port (RJ-45) that supports flow control. Depending on the cable and the adapter used, this port will appear as a DTE or DCE device at the end of the cable.

For connection to a modem, the router has an RJ-45-to-DB-9 cable and a DB-9-to-DB-25 adapter.

For detailed information about connecting devices to the auxiliary port, see the "Connecting to a Console Terminal or Modem" section of Chapter 5, "Cable Connection Procedures for Cisco 1805 DOCSIS Cable Router."

For cable and port pinouts, see the Cisco Modular Access Router Cable Specifications document on Cisco.com.

Preparing to Connect to a Network

When setting up your router, consider distance limitations and potential electromagnetic interference (EMI) as defined by the applicable local and international regulations.

The following section describes network connection considerations for several types of network interfaces:

Ethernet Connections

See the following online documents for more information about network connections and interfaces:

Cisco Interface Cards Installation Guide

Cisco Modular Access Router Cable Specifications

Ethernet Connections

The IEEE has established Ethernet as standard IEEE 802.3. The Ethernet implementations on the Cisco 1805 DOCSIS cable router are as follows:

100BASE-T—2-pair Category 5 or unshielded twisted-pair (UTP) straight-through RJ-45 cable. The maximum segment distance is 328 feet (100 meters).

10BASE-T—Ethernet on UTP cable. The maximum segment distance is 328 feet (100 meters). UTP cables look like the wiring used for ordinary telephones; however, UTP cables meet certain electrical standards that telephone cables might not meet.

See the Cisco Modular Access Router Cable Specifications document for information about Ethernet cables, connectors, and pinouts.

Serial DTE or DCE Devices

A device that communicates over a synchronous serial interface is either a DTE or DCE device. A DCE device provides a clock signal that paces the communications between the device and the router. A DTE device does not provide a clock signal. DTE devices usually connect to DCE devices. The documentation for the device should indicate whether it is a DTE or DCE device. (Some devices have a jumper that allows you to select either DTE mode or DCE mode.) Table 4-1 lists typical DTE and DCE devices.

Table 4-1 Typical DTE and DCE Devices

Device Type
Gender
Typical Devices

DTE

Male1

Terminal

PC

DCE

Female2

Modem

CSU/DSU

Multiplexer

1 If pins protrude from the base of the connector, the connector is male.

2 If the connector has holes to accept pins, the connector is female.


Signaling Standards Supported

The synchronous serial ports available for the router support the following signaling standards: EIA/TIA-232, EIA/TIA-449, V.35, X.21, and EIA-530. You can order a Cisco DB-60 shielded serial transition cable that has the appropriate connector for the standard you specify. The documentation for the device that you want to connect should indicate the standard used for that device. The router end of the shielded serial transition cable has a DB-60 connector, which connects to the DB-60 port on a serial WAN interface card (WIC). The other end of the serial transition cable has the connector that you specify.

The synchronous serial port can be configured as DTE or DCE, depending on the attached cable (except EIA-530, which is DTE only).


Note All serial ports configured as DTE require external clocking from a channel service unit/data service unit (CSU/DSU) or other DCE device.


Distance Limitations

Serial signals can travel a limited distance at any given bit rate; generally, the slower the data rate, the greater the distance. All serial signals are subject to distance limits, beyond which a signal is significantly degraded or is completely lost.

Table 4-2 lists the recommended maximum speeds and distances for each serial interface type; however, you might get good results at speeds and distances greater than those listed, if you understand the electrical problems that might arise and can compensate for them.

Table 4-2 Serial Signal Transmission Speeds and Distances 

 
Distance for EIA/TIA-232 Standar
Distance for EIA/TIA-449, X.21, V.35, and EIA-530 Standard
Rate (bps)
Feet
Meters
Feet
Meters

2400

200

60

4100

1250

4800

100

30

2050

625

9600

50

15

1025

312

19200

25

7.6

513

156

38400

12

3.7

256

78

56000

8.6

2.6

102

31

1544000 (T1)

50

15


Balanced drivers allow EIA/TIA-449 signals to travel greater distances than EIA/TIA-232 signals. Typically, EIA/TIA-449 and EIA-530 can support a 2-Mbps rate, and V.35 can support a 4-Mbps rate.

Asynchronous/Synchronous Serial Module Baud Rates

The following baud-rate limitations apply to the slow-speed serial interfaces in the asynchronous/synchronous serial modules:

Asynchronous interface—Maximum baud rate is 115.2 kbps.

Synchronous interface—Maximum baud rate is 128 kbps, full-duplex.