Cisco 4 port serial network module

A DCE device provides a clock signal between the device and the router. A DTE device does not provide a clock signal. If you cannot find this information in your documentation, see Table 1 to help you determine the proper device type.

Cisco Systems offers ten types of serial cables also called serial adapter cables or transition cables as listed in Table 2. The documentation for the device you plan to connect to the serial port should indicate which interface is used. You can then order a serial transition cable of the correct type. See the "in-1 Smart Serial Cables" section for instructions on connecting the surge protector cable.

A standard serial cable uses a universal pin plug at the network module or WAN interface card end. The network end of each cable provides the physical connectors most commonly used for the interface. Serial cables are not provided with the network module.

Although manufacturing your own serial cables is not recommended because of the small size of the pins on the DB serial connector , cable pinouts are provided in the online document Cisco Modular Access Router Cable Specifications.

All serial signals are subject to distance limits, beyond which the signal degrades significantly or is completely lost. Generally, the slower the data rate, the greater the distance. Table 3 lists recommended maximum speeds and distances for each serial interface type. If you understand and compensate for potential electrical problems, you may get good results at speeds and distances greater than those listed.

For instance, the recommended maximum rate for V. The following data-rate limitations apply to the slow-speed serial interfaces found on asynchronous and synchronous serial modules:. The traffic throughput rate allowed is the full An asynchronous network module provides two or four pin receptacles. Depending on the type of cable, the network end consists of either RJ connectors or male DB connectors. RJto-DB adapters are also available. Ports are numbered from right to left and from bottom to top, as labeled on the module rear panel.

Octal cables are not provided with the network module. Use an octal cable, and adapters if necessary, to connect each of the module's pin receptacles to one or more asynchronous modems, terminals, or other devices. The NM-4T serial network module has four synchronous serial interfaces. The network module supports a total full-duplex throughput of 8 megabits per second Mbps , which can be realized over one port at 8 Mbps or across all four ports at 2 Mbps on each port.

The NM-4T module in any network environment delivers very low price per port and provides higher performance than comparable third-party solutions. For instance, a small or medium-sized Internet service provider ISP with high serial density requirements may find this solution very cost-effective per subscriber. The four-port synchronous sync serial network module NM-4T has four DB ports and provides a data rate of 8 Mbps on port 0, 4 Mbps each on port 0 and port 2, or 2 Mbps on all four ports simultaneously.

The NM-4T network module only supports sync mode. The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared default configuration.

If your network is live, make sure that you understand the potential impact of any command.