rommon1>

Set the configuration register with the confreg command if the router is in ROMmon mode:

rommon 1 > confreg 0x2102

Router#show hardware 
Cisco IOS Software, 2801 Software (C2801-ADVIPSERVICESK9-M), Version 15.1(4)M1, RELEASE SOFTWARE (fc1)

...edited...

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

Router uptime is 33 minutes
System returned to ROM by power-on
System restarted at 11:59:32 UTC Mon Jan 2 2006
System image file is "flash:c2801-advipservicesk9-mz.151-4.M1.bin"
Last reload type: Normal Reload

...edited...

Cisco 2801 (revision 7.0) with 358400K/34816K bytes of memory.
Processor board ID FCZ121715KL
6 FastEthernet interfaces
2 Channelized E1/PRI ports
1 Virtual Private Network (VPN) Module
2 802.11 Radios
DRAM configuration is 64 bits wide with parity disabled.
191K bytes of NVRAM.
125184K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102

Router#

Router#configure terminal 
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#config-register 0x2102
Router(config)#end

!
boot-start-marker
boot system flash:c2801-advipservicesk9-mz.151-4.M1.bin
boot-end-marker
!

Access point for wifi - UNTESTED!

https://community.cisco.com/t5/wireless/wireless-config-on-2811-with-hwic-access-point/td-p/648658 - Broadcast of ssid link

! 1. Configure the VLAN for wireless traffic
interface Vlan10
 ip address 192.168.10.1 255.255.255.0
 no shutdown

! 2. Configure the Radio Interface (Module/Slot/Port - usually 0/3/0 or 0/2/0)
interface Dot11Radio0/3/0
 no ip address
 ! Set channel and power
 station-role root
 no shutdown
 !
 ! 3. Define the SSID
 ssid MyCompanyWireless
   authentication open
   authentication key-management wpa version 2
   wpa-psk ascii 0 SecretPassword123
   guest-mode
 !
 ! 4. Bridge the radio to the VLAN
 bridge-group 10
 bridge-group 10 subscriber-loop-control
 bridge-group 10 block-unknown-source
 no bridge-group 10 source-learning
 no bridge-group 10 unicast-flooding

! 5. Configure the Bridge Virtual Interface (BVI)
interface BVI10
 ip address 192.168.10.2 255.255.255.0
 no shutdown

! 6. (Optional) Configure DHCP for clients on this subnet
ip dhcp pool WLAN_CLIENTS
 network 192.168.10.0 255.255.255.0
 default-router 192.168.10.1
 dns-server 8.8.8.8

Using Analogue BT phones in DTMF

Router(config)#telephony-service setup
Warning: <telephony-service setup> command has been deprecated.
For installation help, please check CME System Administrator Guide.
Goodbye!
Router(config)#

Router#show voice port summary 
                                           IN       OUT
PORT            CH   SIG-TYPE   ADMIN OPER STATUS   STATUS   EC
=============== == ============ ===== ==== ======== ======== ==
0/2/0           --  fxs-ls      up    dorm on-hook  idle     y 
0/2/1           --  fxs-ls      up    dorm on-hook  idle     y 

Router(config)#voice-port 0/2/0
Router(config-voiceport)#signal ?
  groundStart  Ground Start
  loopStart    Loop Start

Router(config-voiceport)#signal loopStart 
Router(config-voiceport)#ring cadence uk?
% Unrecognized command
Router(config-voiceport)#ring cadence ? 
  define     User Defined Cadence
  external   External ringing cadence on/off durations (STCAPP only)
  pattern01  2sec on 4sec off
  pattern02  1sec on 4sec off
  pattern03  1.5sec on 3.5sec off
  pattern04  1sec on 2sec off
  pattern05  1sec on 5sec off
  pattern06  1sec on 3sec off
  pattern07  .8sec on 3.2sec off
  pattern08  1.5sec on 3sec off
  pattern09  1.2sec on 3.7sec off
  pattern10  1.2sec on 4.7sec off
  pattern11  .4sec on .2sec off .4sec on 2sec off
  pattern12  .4sec on .2sec off .4sec on 2.6sec off

Router(config-voiceport)#ring cadence pattern11
Router(config-voiceport)#exit

Running config to call between FXS ports

voice-port 0/2/0
 ring cadence pattern11
 station-id name analogue1
 station-id number 1001
!
voice-port 0/2/1
 ring cadence pattern11
 station-id name analogue2
 station-id number 1002
!
!
!
mgcp profile default
!
!
dial-peer voice 1001 pots
 destination-pattern 1001
 port 0/2/0
!
dial-peer voice 1002 pots
 destination-pattern 1002
 port 0/2/1
!

Complete dump of info.. don't believe anything here, not tested.

voice register global
 mode cme
 load 7911 SCCP11.8-4-4S  ! Ensure this matches your firmware file
 tftp-path flash:
 max-dn 10
 max-pool 10
 source-address <192.168.x.x> port 2000
 !
voice register pool 1
 id mac <AAAA.BBBB.CCCC>  ! Phone MAC Address
 type 7911
 number 1 dn 1
 username <username> password <password>
 codec g711ulaw
 !
voice register dn 1
 number 101 ! Extension number

Two ports of analogue in a VIC cards, 2x RJ-11 sockets

See https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-express/99946-cme-sip-guide.html for sccp config.

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/lanswitch/configuration/12-2sx/lsw-hwic-ethsw-ic.html

!
hostname 2801-1
!
!
bridge irb
!
interface FastEthernet0/0
 no ip address
 no ip route-cache
 speed auto
 full-duplex
 no mop enabled
 bridge-group 1
!
!
interface FastEthernet0/1/0
 no ip address
!
interface FastEthernet0/1/1
 no ip address
!
interface FastEthernet0/1/2
 no ip address
!
interface FastEthernet0/1/3
 no ip address
!
interface BVI1
 ip address 192.168.1.123 255.255.255.0
!
interface BVI2
 ip address 192.168.2.123 255.255.255.0
!
!
bridge 1 protocol ieee
bridge 1 route ip

bridge 2 protocol ieee
bridge 2 route ip
!
!

ntp update-calendar
ntp server 192.168.1.1
ntp peer 192.168.1.2
ntp peer 192.168.1.131
ntp peer 192.168.1.132
ntp peer 192.168.1.133