Cisco 3600 Series Multiservice Platforms

Understanding the 4-Port Sync Serial Network Module (NM-4T)

Document ID: 7264

Updated: Feb 04, 2010



The four-port synchronous (sync) serial network module (NM-4T) has four DB-60 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 DB-60 ports on the NM-4T network module support the Cisco 60-pin "5-in-1" cables used on the Cisco 2500 and Cisco 7000 series routers.




See the Platform Support section of this document.

Components Used

See the Platform Support section of this document.

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.


For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Product Number

NM-4T - Four-Port Sync Serial Network Module


  • Four serial ports.

  • Uses Cisco DB-60 connectors (same cabling as Cisco 2500, Cisco 7000, NM-4A/S, and NM-8A/S). For more information, refer to 60-pin "5-in-1".

  • Supports sync mode only (async mode is not supported).

  • Provides synchronous 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.

  • Does not support bisync or half-duplex.

Platform Support

Cisco IOS® Software Support Cisco 2600, 2600XM Cisco 3620 and 3640 Cisco 3631 Cisco 3660 Cisco 2691, 3725, 3745
NM-4T Not supported Cisco IOS Software Releases 11.2(4)XA, 11.2P, all 11.3, and all of 12.x Cisco IOS Software Releases 12.2(13)T, 12.3(1), 12.3(2)T and later All Cisco IOS Software releases Cisco IOS Software Releases 12.2(13)T, 12.2(11)YT

Note: The Cisco IOS Software releases provided are typically the minimum version required in order to support the platform, module, or feature in question. Use the Software Advisor (registered customers only) to choose appropriate software for your network device, match software features to Cisco IOS Software and CatOS releases, compare Cisco IOS Software releases, or find out which software releases support your hardware.


On the NM-4T network module, the interfaces are addressed as interface serial slot/unit . The units are numbered from right to left. This output is a sample configuration for the NM-4T network module. Configure the NM-4T as you would any other serial interface on a 2500, 7500, and so forth.

Note: There are no framing, clocking, or linecode parameters or commands used in this configuration. The NM-4T network module does not have an integrated CSU/DSU. You need to use an external CSU/DSU.

maui-soho-02(config)# interface Serial 2/0
maui-soho-02(config-if)# ip add
maui-soho-02(config-if)# encapsulation ppp
maui-soho-02(config-if)# no shutdown

For more information on configuring the NM-4T network module, refer to Configuring Serial Interfaces.

Related Information

Updated: Feb 04, 2010
Document ID: 7264