We used this Cisco 1841 router in our office for about 6 months. It was connected to a T1, and has the WIC1DSU-T1 V2 card installed. It worked great.From Cisco's Web Site:

The Cisco 1841 Integrated Services Router is part of the Cisco 1800 Integrated Services Router Series which complements the Integrated Services Router Portfolio.

The Cisco 1841 Integrated Services Router provides the following support:

• Wire-speed performance for concurrent services at T1/E1 WAN rates
• Enhanced investment protection through increased performance and modularity
• Enhanced investment protection through increased modularity
• Increased density through High-Speed WAN Interface Card Slots (two)
• Support for over 90 existing and new modules
• Support for majority of existing WICs, VWICs, and VICs (data mode only)
• Two Integrated 10/100 Fast Ethernet ports
• Security
  • On-board encryption
  • Support of up to 800 VPN tunnels with the AIM Module
  • Antivirus defense support through Network Admission Control (NAC)
  • Intrusion Prevention as well as stateful Cisco IOS Firewall support and many more essential security feature

Here is the boot log:
System Bootstrap, Version 12.3(8r)T9, RELEASE SOFTWARE (fc1)
Technical Support: (c) 2004 by cisco Systems, Inc.
PLD version 0x10
GIO ASIC version 0x127
c1841 processor with 131072 Kbytes of main memory
Main memory is configured to 64 bit mode with parity disabledReadonly ROMMON initialized
program load complete, entry point: 0x8000f000, size: 0xc100Initializing ATA monitor library.......
program load complete, entry point: 0x8000f000, size: 0xc100Initializing ATA monitor library.......program load complete, entry point: 0x8000f000, size: 0xefeba4
Self decompressing the image : [OK]Smart Init is enabled
smart init is sizing iomem
ID MEMORY_REQ TYPE
0X003AA110 public buffer pools
0X00211000 public particle pools
0X0052 0X0001A800 Card in slot 0
0X000021B8 Onboard USBIf any of the above Memory Requirements are
"UNKNOWN", you may be using an unsupported
configuration or there is a software problem and
system operation may be compromised.Allocating additional 7159167 bytes to IO Memory.
PMem allocated: 118489088 bytes; IOMem allocated: 15728640 bytes Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013. cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706Cisco IOS Software, 1841 Software (C1841-IPBASE-M), Version 12.4(6)T1, RELEASE SOFTWARE (fc3)
Technical Support: (c) 1986-2006 by Cisco Systems, Inc.
Compiled Thu 11-May-06 17:58 by kellythw
Image text-base: 0x6008B54C, data-base: 0x61580000Cisco 1841 (revision 6.0) with 115712K/15360K bytes of memory.
Processor board ID FTX1048Z16E
2 FastEthernet interfaces
1 Serial interface
WIC T1-DSU
DRAM configuration is 64 bits wide with parity disabled.
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)
Even though this router works perfectly, it is being sold