diff --git a/audio-linux.go b/audio-linux.go
index f6256ee..4ef25ad 100644
--- a/audio-linux.go
+++ b/audio-linux.go
@@ -11,6 +11,8 @@ import (
 	"github.com/akosmarton/papipes"
 )
 
+const audioSampleRate = 48000
+
 type audioStruct struct {
 	source papipes.Source
 	sink   papipes.Sink
@@ -154,18 +156,18 @@ func (a *audioStruct) loop() {
 func (a *audioStruct) init(devName string) error {
 	a.source.Name = "kappanhang-" + devName
 	a.source.Filename = "/tmp/kappanhang-" + devName + ".source"
-	a.source.Rate = 48000
+	a.source.Rate = audioSampleRate
 	a.source.Format = "s16le"
 	a.source.Channels = 1
-	a.source.SetProperty("device.buffering.buffer_size", (48000*16)/10) // 100 ms
+	a.source.SetProperty("device.buffering.buffer_size", (audioSampleRate*16)/10) // 100 ms
 	a.source.SetProperty("device.description", "kappanhang: "+devName)
 
 	a.sink.Name = "kappanhang-" + devName
 	a.sink.Filename = "/tmp/kappanhang-" + devName + ".sink"
-	a.sink.Rate = 48000
+	a.sink.Rate = audioSampleRate
 	a.sink.Format = "s16le"
 	a.sink.Channels = 1
-	a.sink.SetProperty("device.buffering.buffer_size", (48000*16)/10)
+	a.sink.SetProperty("device.buffering.buffer_size", (audioSampleRate*16)/10)
 	a.sink.SetProperty("device.description", "kappanhang: "+devName)
 
 	if err := a.source.Open(); err != nil {
diff --git a/audiostream.go b/audiostream.go
index 2b39c41..d642006 100644
--- a/audiostream.go
+++ b/audiostream.go
@@ -128,7 +128,7 @@ func (s *audioStream) loop() {
 }
 
 func (s *audioStream) init(devName string) error {
-	if err := s.common.init("audio", 50003); err != nil {
+	if err := s.common.init("audio", audioStreamPort); err != nil {
 		return err
 	}
 
diff --git a/controlstream.go b/controlstream.go
index 96f92b6..a1df500 100644
--- a/controlstream.go
+++ b/controlstream.go
@@ -8,6 +8,10 @@ import (
 	"time"
 )
 
+const controlStreamPort = 50001
+const serialStreamPort = 50002
+const audioStreamPort = 50003
+
 type controlStream struct {
 	common streamCommon
 	serial serialStream
@@ -91,6 +95,7 @@ func (s *controlStream) sendPktAuth(magic byte) error {
 
 func (s *controlStream) sendRequestSerialAndAudio() error {
 	log.Debug("requesting serial and audio stream")
+
 	p := []byte{0x90, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 		byte(s.common.localSID >> 24), byte(s.common.localSID >> 16), byte(s.common.localSID >> 8), byte(s.common.localSID),
 		byte(s.common.remoteSID >> 24), byte(s.common.remoteSID >> 16), byte(s.common.remoteSID >> 8), byte(s.common.remoteSID),
@@ -106,9 +111,10 @@ func (s *controlStream) sendRequestSerialAndAudio() error {
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 		0x2b, 0x3f, 0x55, 0x5c, 0x00, 0x00, 0x00, 0x00, // username: beer
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-		0x01, 0x01, 0x04, 0x04, 0x00, 0x00, 0xbb, 0x80,
-		0x00, 0x00, 0xbb, 0x80, 0x00, 0x00, 0xc3, 0x52,
-		0x00, 0x00, 0xc3, 0x53, 0x00, 0x00, 0x00, 0xa0,
+		0x01, 0x01, 0x04, 0x04, 0x00, 0x00, byte(audioSampleRate >> 8), byte(audioSampleRate & 0xff),
+		0x00, 0x00, byte(audioSampleRate >> 8), byte(audioSampleRate & 0xff),
+		0x00, 0x00, byte(serialStreamPort >> 8), byte(serialStreamPort & 0xff),
+		0x00, 0x00, byte(audioStreamPort >> 8), byte(audioStreamPort & 0xff), 0x00, 0x00, 0x00, 0xa0,
 		0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 	if err := s.common.pkt0.sendTrackedPacket(&s.common, p); err != nil {
 		return err
@@ -181,7 +187,7 @@ func (s *controlStream) handleRead(r []byte) error {
 			// 0x80, 0x00, 0x00, 0x90, 0xc7, 0x0e, 0x86, 0x01,
 			// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 			// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-			// 0x49, 0x43, 0x2d, 0x37, 0x30, 0x35, 0x00, 0x00,
+			// 0x49, 0x43, 0x2d, 0x37, 0x30, 0x35, 0x00, 0x00, // IC-705 in plain text
 			// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 			// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 			// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -257,7 +263,7 @@ func (s *controlStream) loop() {
 func (s *controlStream) init() error {
 	log.Debug("init")
 
-	if err := s.common.init("control", 50001); err != nil {
+	if err := s.common.init("control", controlStreamPort); err != nil {
 		return err
 	}
 
diff --git a/serialstream.go b/serialstream.go
index 477e9e6..e57a4cd 100644
--- a/serialstream.go
+++ b/serialstream.go
@@ -210,7 +210,7 @@ func (s *serialStream) loop() {
 }
 
 func (s *serialStream) init(devName string) error {
-	if err := s.common.init("serial", 50002); err != nil {
+	if err := s.common.init("serial", serialStreamPort); err != nil {
 		return err
 	}