Cisco WAN Interface Cards

2-Port Async/Sync WAN Interface Card (WIC-2A/S)

Document ID: 7259

Updated: Feb 04, 2010



The dual-serial port WAN Interface Card (WIC-2A/S) provides higher levels of serial port density for a single WIC and is supported on the Cisco 1700, 2600, and 3600 series. The low serial speed WIC-2A/S supports up to 128 Kbps synchronous or 115.2 Kbps asynchronous serial links. Each port on a WIC is a different physical interface and can support different protocols such as Point-to-Point Protocol (PPP) or Frame Relay and Data Terminal Equipment/Data Communications Equipment (DTE/DCE). This WIC supports mixed asynchronous and synchronous operation on a single card as well.

These dual-serial port WICs feature Cisco's new, compact, Smart Serial connectors to support a wide variety of electrical interfaces when used with the appropriate transition cable. This includes: V.35, RS-232, RS-449, RS-530, RS-530A in male and female versions for both DTE and DCE devices. This feature provides easy configuration and reconfiguration as network requirements change, without the need of purchasing a different serial interface card.

Two cables are required to support the two ports on the WIC.




There are no specific requirements for this document.

Components Used

The information in this document is based on the WIC-2A/S.

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.


Refer to Cisco Technical Tips Conventions for more information on document conventions.

Product Number

WIC-2A/S—Two-Port Asynchronous/Synchronous WIC


The WIC-2A/S provides two serial ports using the Smart Serial connector.

  • Aysnchronous support with a maximum speed of 115.2 Kbps and a minimum of 600 bps. If you need to run at speeds lower than 600 bps, use the AUX port instead.

  • Synchronous support with a maximum speed of 128 Kbps.


Cable Type Product Number Length Male/Female
V.35 DTE CAB-SS-V35MT(=) 10 feet / 3 meters Male
V.35 DCE CAB-SS-V35FC(=) 10 feet / 3 meters Female
RS-232 DTE CAB-SS-232MT(=) 10 feet / 3 meters Male
RS-232 DCE CAB-SS-232FC(=) 10 feet / 3 meters Female
RS-449 DTE CAB-SS-449MT(=) 10 feet / 3 meters Male
RS-449 DCE CAB SS-449FC(=) 10 feet / 3 meters Female
X.21 DTE CAB-SS-X21MT(=) 10 feet / 3 meters Male
X.21 DCE CAB-SS-X21FC(=) 10 feet / 3 meters Female
EIA-530 DTE CAB-SS-530MT(=) 10 feet / 3 meters Male
EIA-530A DTE CAB-SS-530AMT(=) 10 feet / 3 meters Male

Platform Support

Platform Cisco 1600 Cisco 1700 Cisco 2600 Cisco 2600XM Cisco 3620,3640,3660 Cisco 3631 Cisco 2691,3725,3745
Carrier Module Not required Not required On-board NM-2W On-board NM-2W NM-1E2W, NM-1E1R2W, NM-2E2W NM-1FE2W, NM-1FE1R2W, NM-2FE2W, NM-2W On-board On-board NM-1FE2W, NM-1FE1R2W, NM-2FE2W, NM-2W
Cisco IOS® Software Support Not supported All Cisco IOS Software versions All Cisco IOS Software versions Cisco IOS Software versions 12.0(7)XK, 12.1(1)T, 12.2, 12.2T All Cisco IOS Software versions 12.2(8)T1 Not supported Cisco IOS Software versions 12.0(7)XK, 12.1(1)T, 12.2, 12.2T All Cisco IOS Software versions All Cisco IOS Software versions All Cisco IOS Software versions

Note: The Cisco 1600 series is not capable of supporting the WIC-2A/S due to the lack of Serial Communications Controllers.

The NM-1E2W, NM-1E1R2W, and NM-2E2W network modules do not have enough performance to support the WIC-2A/S.

Known Problems

The WIC-2A/S can be damaged by excessive electrostatic discharge. You can minimize this electrostatic discharge in these ways:

  • Use shielded cable end-to-end.

  • Use a data surge protector that protects against surges over +/- 18v.

  • Use an optical isolator (best protection).


The default setting for this module is synchronous. Issue the physical-layer async command in order to configure the module for asynchronous communication. Here is a section of an asynchronous configuration:

maui-soho-01(config)#interface Serial 2/0
maui-soho-01(config-if)#physical-layer async

!--- Places the interface in asynchronous mode. 
!--- Continue to configure this serial interface just as you 
!--- would configure an Async Interface.

maui-soho-01(config-if)#ip add
maui-soho-01(config-if)#async mode interactive
maui-soho-01(config-if)#async default routing
maui-soho-01(config-if)#dialer in-band
maui-soho-01(config-if)#dialer map ip name maui-nas-01 broadcast 5551111

!--- The above commands are part of a broader Dial-on-Demand Routing (DDR)
!--- configuration.

Refer to Configuring Dialout using a Modem on the AUX Port in order to connect a modem to this interface. Even though the document refers to the AUX port, the configuration is very similar.

Issue the physical-layer sync command or the no physical-layer async command in order to revert to the default sync mode. Refer to Configuring Serial Interfaces for more information on how to configure the interface for normal serial operation.

Related Information

Updated: Feb 04, 2010
Document ID: 7259