diff --git a/src/classic/avdtp.c b/src/classic/avdtp.c
index d06e3d5ca..b298e6346 100644
--- a/src/classic/avdtp.c
+++ b/src/classic/avdtp.c
@@ -190,14 +190,6 @@ avdtp_connection_t * avdtp_create_connection(bd_addr_t remote_addr, avdtp_contex
     return connection;
 }
 
-void avdtp_init_audio_buffer(avdtp_stream_endpoint_t * stream_endpoint, uint8_t * storage, int storage_size){
-    if (!stream_endpoint){
-        printf("cannot init audio buffer, no stream_endpoint\n");
-        return;
-    }
-    btstack_ring_buffer_init(&stream_endpoint->audio_ring_buffer, storage, storage_size);
-}
-
 void avdtp_init_sbc_buffer(avdtp_stream_endpoint_t * stream_endpoint, uint8_t * storage, int storage_size){
     if (!stream_endpoint){
         printf("cannot init audio buffer, no stream_endpoint\n");
diff --git a/src/classic/avdtp.h b/src/classic/avdtp.h
index d669bd492..e9c92160f 100644
--- a/src/classic/avdtp.h
+++ b/src/classic/avdtp.h
@@ -454,9 +454,7 @@ typedef struct avdtp_stream_endpoint {
     uint32_t acc_num_missed_samples;
     btstack_sbc_encoder_state_t sbc_encoder_state;
     uint16_t sequence_number;
-    uint32_t fill_audio_ring_buffer_timeout_ms;
     
-    btstack_ring_buffer_t audio_ring_buffer;
     btstack_ring_buffer_t sbc_ring_buffer;
 } avdtp_stream_endpoint_t;
 
@@ -496,9 +494,7 @@ void avdtp_set_configuration(uint16_t con_handle, uint8_t int_seid, uint8_t acp_
 void avdtp_reconfigure(uint16_t con_handle, uint8_t acp_seid, uint16_t configured_services_bitmap, avdtp_capabilities_t configuration, avdtp_context_t * context);
 void avdtp_suspend(uint16_t con_handle, uint8_t acp_seid, avdtp_context_t * context);
 
-void avdtp_init_audio_buffer(avdtp_stream_endpoint_t * stream_endpoint, uint8_t * storage, int storage_size);
 void avdtp_init_sbc_buffer(avdtp_stream_endpoint_t * stream_endpoint, uint8_t * storage, int storage_size);
-
 #if defined __cplusplus
 }
 #endif
diff --git a/test/avdtp/Makefile b/test/avdtp/Makefile
index 5b38c4d8f..0ad70e693 100644
--- a/test/avdtp/Makefile
+++ b/test/avdtp/Makefile
@@ -71,7 +71,8 @@ AVDTP += \
 	avdtp_sink.c  		\
 	btstack_ring_buffer.c \
 
-AVDTP_TESTS = avdtp_source_demo avdtp_sink_test portaudio_test sine_encode_decode_ring_buffer_test sine_encode_decode_test sine_encode_decode_performance_test
+AVDTP_TESTS = avdtp_source_demo avdtp_sink_test portaudio_test
+#sine_encode_decode_ring_buffer_test sine_encode_decode_test sine_encode_decode_performance_test
 
 CORE_OBJ    = $(CORE:.c=.o)
 COMMON_OBJ  = $(COMMON:.c=.o) 
diff --git a/test/avdtp/avdtp_source_demo.c b/test/avdtp/avdtp_source_demo.c
index 9851884a8..103065cfb 100644
--- a/test/avdtp/avdtp_source_demo.c
+++ b/test/avdtp/avdtp_source_demo.c
@@ -468,8 +468,10 @@ typedef struct {
     int right_phase;
 } paTestData;
 
+static uint32_t fill_audio_ring_buffer_timeout_ms = 50;
+
 static uint8_t audio_samples_storage[44100*4]; // 1s buffer
-// static btstack_ring_buffer_t audio_ring_buffer;
+static btstack_ring_buffer_t audio_ring_buffer;
 
 static uint8_t sbc_samples_storage[44100*4];
 // static btstack_ring_buffer_t sbc_ring_buffer;
@@ -493,15 +495,15 @@ static void avdtp_source_stream_endpoint_run(avdtp_stream_endpoint_t * stream_en
     int audio_bytes_to_read = num_audio_samples_to_read * BYTES_PER_AUDIO_SAMPLE; 
 
     // printf("run: audio_bytes_to_read:        %d\n", audio_bytes_to_read);
-    // printf("     audio buf, bytes available: %d\n", btstack_ring_buffer_bytes_available(&stream_endpoint->audio_ring_buffer));
+    // printf("     audio buf, bytes available: %d\n", btstack_ring_buffer_bytes_available(&audio_ring_buffer));
     // printf("     sbc buf,   bytes free:      %d\n", btstack_ring_buffer_bytes_free(&stream_endpoint->sbc_ring_buffer));
 
-    while (btstack_ring_buffer_bytes_available(&stream_endpoint->audio_ring_buffer) >= audio_bytes_to_read
+    while (btstack_ring_buffer_bytes_available(&audio_ring_buffer) >= audio_bytes_to_read
         && btstack_ring_buffer_bytes_free(&stream_endpoint->sbc_ring_buffer) >= 120){ // TODO use real value
         
         uint32_t number_of_bytes_read = 0;
         uint8_t pcm_frame[256*BYTES_PER_AUDIO_SAMPLE];
-        btstack_ring_buffer_read(&stream_endpoint->audio_ring_buffer, pcm_frame, audio_bytes_to_read, &number_of_bytes_read); 
+        btstack_ring_buffer_read(&audio_ring_buffer, pcm_frame, audio_bytes_to_read, &number_of_bytes_read); 
         // printf("     num audio bytes read %d\n", number_of_bytes_read);
         btstack_sbc_encoder_process_data((int16_t *) pcm_frame);
         
@@ -517,15 +519,15 @@ static void avdtp_source_stream_endpoint_run(avdtp_stream_endpoint_t * stream_en
     }
 }
 
-static void fill_audio_ring_buffer(void *userData, int num_samples_to_write, avdtp_stream_endpoint_t * stream_endpoint){
+static void fill_audio_ring_buffer(void *userData, int num_samples_to_write){
     paTestData *data = (paTestData*)userData;
     int count = 0;
-    while (btstack_ring_buffer_bytes_free(&stream_endpoint->audio_ring_buffer) >= BYTES_PER_AUDIO_SAMPLE && count < num_samples_to_write){
+    while (btstack_ring_buffer_bytes_free(&audio_ring_buffer) >= BYTES_PER_AUDIO_SAMPLE && count < num_samples_to_write){
         uint8_t write_data[BYTES_PER_AUDIO_SAMPLE];
         *(int16_t*)&write_data[0] = data->source[data->left_phase];
         *(int16_t*)&write_data[2] = data->source[data->right_phase];
         
-        btstack_ring_buffer_write(&stream_endpoint->audio_ring_buffer, write_data, BYTES_PER_AUDIO_SAMPLE);
+        btstack_ring_buffer_write(&audio_ring_buffer, write_data, BYTES_PER_AUDIO_SAMPLE);
         count++;
 
         data->left_phase += 1;
@@ -541,11 +543,11 @@ static void fill_audio_ring_buffer(void *userData, int num_samples_to_write, avd
 
 static void avdtp_fill_audio_ring_buffer_timeout_handler(btstack_timer_source_t * timer){
     avdtp_stream_endpoint_t * stream_endpoint = btstack_run_loop_get_timer_context(timer);
-    btstack_run_loop_set_timer(&stream_endpoint->fill_audio_ring_buffer_timer, stream_endpoint->fill_audio_ring_buffer_timeout_ms); // 2 seconds timeout
+    btstack_run_loop_set_timer(&stream_endpoint->fill_audio_ring_buffer_timer, fill_audio_ring_buffer_timeout_ms); // 2 seconds timeout
     btstack_run_loop_add_timer(&stream_endpoint->fill_audio_ring_buffer_timer);
     uint32_t now = btstack_run_loop_get_time_ms();
 
-    uint32_t update_period_ms = stream_endpoint->fill_audio_ring_buffer_timeout_ms;
+    uint32_t update_period_ms = fill_audio_ring_buffer_timeout_ms;
     if (stream_endpoint->time_audio_data_sent > 0){
         update_period_ms = now - stream_endpoint->time_audio_data_sent;
     } 
@@ -557,7 +559,7 @@ static void avdtp_fill_audio_ring_buffer_timeout_handler(btstack_timer_source_t
         stream_endpoint->acc_num_missed_samples -= 1000;
     }
 
-    fill_audio_ring_buffer(&sin_data, num_samples, stream_endpoint);
+    fill_audio_ring_buffer(&sin_data, num_samples);
     stream_endpoint->time_audio_data_sent = now;
 
     avdtp_source_stream_endpoint_run(stream_endpoint);
@@ -568,7 +570,7 @@ static void avdtp_fill_audio_ring_buffer_timer_start(avdtp_stream_endpoint_t * s
     btstack_run_loop_remove_timer(&stream_endpoint->fill_audio_ring_buffer_timer);
     btstack_run_loop_set_timer_handler(&stream_endpoint->fill_audio_ring_buffer_timer, avdtp_fill_audio_ring_buffer_timeout_handler);
     btstack_run_loop_set_timer_context(&stream_endpoint->fill_audio_ring_buffer_timer, stream_endpoint);
-    btstack_run_loop_set_timer(&stream_endpoint->fill_audio_ring_buffer_timer, stream_endpoint->fill_audio_ring_buffer_timeout_ms); // 50 ms timeout
+    btstack_run_loop_set_timer(&stream_endpoint->fill_audio_ring_buffer_timer, fill_audio_ring_buffer_timeout_ms); // 50 ms timeout
     btstack_run_loop_add_timer(&stream_endpoint->fill_audio_ring_buffer_timer);
 }
 
@@ -593,13 +595,19 @@ static void avdtp_source_stream_data_stop(avdtp_stream_endpoint_t * stream_endpo
         log_error("no stream_endpoint found");
         return;
     }
-    if (stream_endpoint->state != AVDTP_STREAM_ENDPOINT_STREAMING) {
-        printf("stream_endpoint in wrong state %d\n", stream_endpoint->state);
-        return;
+    switch (stream_endpoint->state){
+        case AVDTP_STREAM_ENDPOINT_STREAMING_W2_SEND:
+        case AVDTP_STREAM_ENDPOINT_STREAMING:
+            // TODO: initialize randomly sequence number
+            stream_endpoint->sequence_number = 0;
+            stream_endpoint->state = AVDTP_STREAM_ENDPOINT_STREAMING;
+            avdtp_fill_audio_ring_buffer_timer_stop(stream_endpoint);
+            break;
+        default:
+            printf("stream_endpoint in wrong state %d\n", stream_endpoint->state);
+            return;
     } 
-    // TODO: initialize randomly sequence number
-    stream_endpoint->sequence_number = 0;
-    avdtp_fill_audio_ring_buffer_timer_stop(stream_endpoint);
+
 }
 
 static void stdin_process(btstack_data_source_t *ds, btstack_data_source_callback_type_t callback_type){
@@ -707,7 +715,7 @@ int btstack_main(int argc, const char * argv[]){
     memset(audio_samples_storage, 0, sizeof(audio_samples_storage));
     memset(sbc_samples_storage, 0, sizeof(sbc_samples_storage));
     
-    avdtp_init_audio_buffer(local_stream_endpoint, audio_samples_storage, sizeof(audio_samples_storage));
+    btstack_ring_buffer_init(&audio_ring_buffer, audio_samples_storage, sizeof(audio_samples_storage));
     avdtp_init_sbc_buffer(local_stream_endpoint, sbc_samples_storage, sizeof(sbc_samples_storage));
         
     /* initialise sinusoidal wavetable */