Yes, the phone´s HTTP interface allows remote users to simulate the usage of the phone´s keypad and a few special features.

Syntax:

The URL to press a key is the address of your phone with the page 'command.htm' and the post value "key=KEYEVENT":

• http://phoneIP/command.htm?key=KEYEVENT

The following KEYEVENTs are known to the firmware of the phone (written exactly as shown below in capital letters):
snom3xx:

• CANCEL = "Cancel" key pressed
• ENTER = "Enter" key pressed
• OFFHOOK = simulates lifting up the handset
  
• ONHOOK = simulates hanging up the handset
• RIGHT = simulates pressing right navigation key
• LEFT = simulates pressing left navigation key
• UP = simulates pressing "up" navigation key
• DOWN = simulates pressing "down" navigation key
• MENU = simulates pressing MENU key (not used in FW 7 anymore)
• REDIAL = simulates pressing REDIAL key
• DND = simulates pressing DND key
• F1, F2, F3, F4 = simulates pressing context sensitive soft function keys (located directly below the display of the phone) NOTE: snom 190/200 have no key F4
  
• SPEAKER = simulates pressing SPEAKER key
• TRANSFER = simulates pressing TRANSFER key
• F_R = simulates pressing HOLD key
• DISCONNECT = disconnects a call
  
• 0-9, *, # = simulates pressing the alphanumeric keypad
• P1-PX = simulates pressing free programmable function keys (X=12 for snom320/360/370, X=4 for snom300).
• EK0- EKmax =  simulates pressing free programmable function keys of expansion module

snom2xx/snom1xx only:

• CLEAR = "Clear" Key pressed
• FUNCTION = "F" (Menu Key on snom200/190) pressed
• RECALL = "Hold" button in the left lower corner of the keypad of the snom 190/200/220
• P1-PX = simulates pressing free programmable function keys (X=5 for snom190/200/220).
• EK0- EKmax = extension keyboard snom220
  

There are also other functions which can be controlled remotely:

• Remote Dialing: http://phoneIP/command.htm?number=NUMBER&outgoing_uri=URI
• Remote Ringtone Playing: http://phoneIP/line_login.htm?PLAY_RINGER:X=Play+Ringer (X=1..9)
• Remote Reboot: http://phoneIP/advanced_update.htm?reboot=Reboot
• Remote Reset: http://phoneIP/advanced_update.htm?reset=Reset

Examples:

• http://192.168.0.1/command.htm?key=OFFHOOK simulates the user of the phone with the IP address 192.168.0.1 picking up the handset.

• http://192.168.0.1/command.htm?number=12345678&outgoing_uri=123@domain1 will dial 1234. In order to place a call from a specific outgoing line (SIP account, identity) attach "&outgoing_uri=user@domain1"
• http://192.168.0.1/line_login.htm?PLAY_RINGER:9=Play+Ringer plays  the ring tone 9  remotely

• Attended Transfer (Incoming call A, transferred by B to C):

  1. http://192.168.6.252/command.htm?key=F_R -->Holds the call "A"

  2. http://192.168.6.252/command.htm?key=X (X=0-9) --> Repeat this  for each digit of the number "C" to be transferred to

  3. http://192.168.6.252/command.htm?key=ENTER --> "B" makes a call to "C" and announces transfer

  4. http://192.168.6.252/command.htm?key=TRANSFER --> call is transferrred
     NOTE: If the parameter "Call Join on Xfer (2 calls)" has been set to "ON" the "Calls on Hold" list is displayed instead (in this remote scenario not recommended, since it would require navigation through the list and a final command http://192.168.6.252/command.htm?key=TRANSFER/ENTER)