diff --git a/apps/trx/ctrl_if.py b/apps/trx/ctrl_if.py
index 58960c5..0129d7f 100644
--- a/apps/trx/ctrl_if.py
+++ b/apps/trx/ctrl_if.py
@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # GR-GSM based transceiver
-# Transceiver UDP interface
+# CTRL interface implementation
 #
 # (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>
 #
@@ -22,25 +22,18 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-import socket
-import select
-
 from udp_link import UDPLink
 
 class CTRLInterface(UDPLink):
-	def __init__(self, remote_addr, remote_port, bind_port, radio_if):
-		print("[i] Init TRX CTRL interface")
-		UDPLink.__init__(self, remote_addr, remote_port, bind_port)
-		self.tb = radio_if
-
-	def shutdown(self):
-		print("[i] Shutdown TRX CTRL interface")
-		UDPLink.shutdown(self)
-
 	def handle_rx(self, data):
 		if self.verify_req(data):
 			request = self.prepare_req(data)
-			self.parse_cmd(request)
+			rc = self.parse_cmd(request)
+
+			if type(rc) is tuple:
+				self.send_response(request, rc[0], rc[1])
+			else:
+				self.send_response(request, rc)
 		else:
 			print("[!] Wrong data on CTRL interface")
 
@@ -72,61 +65,18 @@
 
 		return True
 
-	def parse_cmd(self, request):
-		response_code = "0"
-
-		# Power control
-		if self.verify_cmd(request, "POWERON", 0):
-			print("[i] Recv POWERON cmd")
-			if not self.tb.trx_started:
-				if self.tb.check_available():
-					print("[i] Starting transceiver...")
-					self.tb.trx_started = True
-					self.tb.start()
-				else:
-					print("[!] Transceiver isn't ready to start")
-					response_code = "-1"
-			else:
-				print("[!] Transceiver already started!")
-				response_code = "-1"
-		elif self.verify_cmd(request, "POWEROFF", 0):
-			print("[i] Recv POWEROFF cmd")
-			print("[i] Stopping transceiver...")
-			self.tb.trx_started = False
-			# TODO: flush all buffers between blocks
-			self.tb.stop()
-		elif self.verify_cmd(request, "SETRXGAIN", 1):
-			print("[i] Recv SETRXGAIN cmd")
-			# TODO: check gain value
-			gain = int(request[1])
-			self.tb.set_gain(gain)
-
-		# Tuning Control
-		elif self.verify_cmd(request, "RXTUNE", 1):
-			print("[i] Recv RXTUNE cmd")
-			# TODO: check freq range
-			freq = int(request[1]) * 1000
-			self.tb.set_fc(freq)
-		elif self.verify_cmd(request, "TXTUNE", 1):
-			print("[i] Recv TXTUNE cmd")
-			# TODO: is not implemented yet
-
-		# Misc
-		elif self.verify_cmd(request, "ECHO", 0):
-			print("[i] Recv ECHO cmd")
-
-		# Wrong / unknown command
-		else:
-			print("[!] Wrong request on CTRL interface")
-			response_code = "-1"
-
-		# Anyway, we need to respond
-		self.send_response(request, response_code)
-
-	def send_response(self, request, response_code):
+	def send_response(self, request, response_code, params = None):
 		# Include status code, for example ["TXTUNE", "0", "941600"]
-		request.insert(1, response_code)
+		request.insert(1, str(response_code))
+
+		# Optionally append command specific parameters
+		if params is not None:
+			request += params
+
 		# Add the response signature, and join back to string
 		response = "RSP " + " ".join(request) + "\0"
 		# Now we have something like "RSP TXTUNE 0 941600"
 		self.send(response)
+
+	def parse_cmd(self, request):
+		raise NotImplementedError