Cisco Cisco IOS Software Release 15.0(1)M

The Cisco 1841 router supports any combination of one or two of the following WAN interface cards 
(WICs) or multiflex voice/WAN interface cards (VWICs) (data only), which are shared with the 
Cisco 1700, Cisco 2600, and Cisco 3600 series routers: 

WIC-1T: one-port high-speed serial (synchronous/asynchronous)

WIC-2T: two-port high-speed serial (synchronous/asynchronous)

WIC-2A/S: two-port low-speed serial (synchronous/asynchronous) (up to 128 kb/s)

WIC-1ADSL: one-port ADSL

WIC-1ADSL-I-DG: one-port ADSLoISDN WIC

WIC-1ADSL-DG: one-port ADSLoPOTS WIC with dying gasp

WIC-1B-S/T-V3: one-port ISDN WIC (dial and leased line)

WIC-1B-U-V2: one-port ISDN BRI NT-1 WIC for the Cisco 1700, 1800, 2600, 3600, and 3700 
series

WIC-1DSU-56K4: one-port integrated 56/64-kb/s 4-wire DSU/CSU

WIC-1DSU-T1-V2: updated one-port T1/fractional T1 DSU/CSU WIC

WIC-1SHDSL: one-port G.SHDSL

WIC-1SHDSL-V2

WIC-1AM: one-port analog modem

WIC-2AM: two-port analog modem

HWIC-4A/S: four low-speed sync/async serial ports

HWIC-4ESW: four-port 10/100 Ethernet switch interface cards

HWIC-8A/S-RS232: eight low-speed sync/async serial ports, EIA-232 only

HWIC-8A: eight async EIA-232 serial ports

HWIC-AP-G

HWIC-AP-AG

The following T1/E1 multiflex VWICs are also supported on the Cisco 1841 for data applications only:

VWIC-1MFT-E1: one-port RJ-48 multiflex trunk (E1)

VWIC-2MFT-E1: two-port RJ-48 multiflex trunk (E1)

VWIC-1MFT-G703: one-port RJ-48 multiflex trunk (G.703)

VWIC-2MFT-G703: two-port RJ-48 multiflex trunk (G.703)

VWIC-1MFT-T1: one-port RJ-48 multiflex trunk (T1)

VWIC-2MFT-T1: two-port RJ-48 multiflex trunk (T1)

VWIC-2MFT-E1-DI: two-port RJ-48 multiflex trunk (E1) (with drop and insert)

VWIC-2MFT-T1-DI: two-port RJ-48 multiflex trunk (T1) (with drop and insert)

VWIC2-1MFT-T1/E1: 1-port T1/E1 voice/WAN with drop and insert (D&I)

VWIC2-2MFT-T1/E1: 2-port T1/E1 voice/WAN with drop and insert (D&I)

VWIC2-1MFT-G703: 1-port T1/E1 voice/WAN with drop and insert (D&I) and unstructured E1 
(G703)