diff --git a/example/hfp_ag_demo.c b/example/hfp_ag_demo.c
index f628f5eb7..1707e7edd 100644
--- a/example/hfp_ag_demo.c
+++ b/example/hfp_ag_demo.c
@@ -595,7 +595,7 @@ static void send_sco_data(void){
     if ((count & SCO_REPORT_PERIOD) == 0) printf("Sent %u\n", count);
 }
 
-static void sco_packet_handler(uint8_t packet_type, uint8_t * packet, uint16_t size){
+static void sco_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){
     switch (packet_type){
         case HCI_EVENT_PACKET:
             if (packet[0] == HCI_EVENT_SCO_CAN_SEND_NOW){
diff --git a/example/hsp_ag_demo.c b/example/hsp_ag_demo.c
index 79df9d4b1..32782dc95 100644
--- a/example/hsp_ag_demo.c
+++ b/example/hsp_ag_demo.c
@@ -215,16 +215,26 @@ static void send_sco_data(void){
     hci_request_sco_can_send_now_event();
 
     static int count = 0;
-    count++;
-    if ((count & SCO_REPORT_PERIOD) == 0) printf("Sent %u\n", count);
+    if ((count & SCO_REPORT_PERIOD)) return;
+    printf("SCO packets sent: %u\n", count);
 }
 
-static void sco_packet_handler(uint8_t packet_type, uint8_t * packet, uint16_t size){
-    return;
+static void sco_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){
     static int count = 0;
-    count++;
-    if ((count & SCO_REPORT_PERIOD)) return;
-    printf("SCO packets %u\n", count);
+    switch (packet_type){
+        case HCI_EVENT_PACKET:
+            if (packet[0] == HCI_EVENT_SCO_CAN_SEND_NOW){
+                send_sco_data();
+            }
+            break;
+        case HCI_SCO_DATA_PACKET:
+            count++;
+            if ((count & SCO_REPORT_PERIOD)) return;
+            printf("SCO packets received: %u\n", count);
+            break;
+        default:
+            break;
+    }
 }
 
 static void packet_handler(uint8_t * event, uint16_t event_size){
@@ -233,9 +243,6 @@ static void packet_handler(uint8_t * event, uint16_t event_size){
             if (event[2] != HCI_STATE_WORKING) break;
             show_usage();
             break;
-        case HCI_EVENT_SCO_CAN_SEND_NOW:
-            send_sco_data();
-            break;
         case HCI_EVENT_HSP_META:
             switch (event[2]) {
                 case HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE:
diff --git a/example/hsp_hs_demo.c b/example/hsp_hs_demo.c
index f1240b943..ffa509db0 100644
--- a/example/hsp_hs_demo.c
+++ b/example/hsp_hs_demo.c
@@ -215,16 +215,24 @@ static void send_sco_data(void){
     hci_request_sco_can_send_now_event();
 
     static int count = 0;
-    count++;
-    if ((count & 15) == 0) printf("Sent %u\n", count);
+    if ((count & SCO_REPORT_PERIOD)) return;
+    printf("SCO packets sent: %u\n", count);
 }
 
-static void sco_packet_handler(uint8_t packet_type, uint8_t * packet, uint16_t size){
+static void sco_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){
     static int count = 0;
-    // hexdumpf(packet, size);
-    count++;
-    if ((count & SCO_REPORT_PERIOD)) return;
-    printf("SCO packets %u\n", count);
+    switch (packet_type){
+        case HCI_EVENT_PACKET:
+            if (packet[0] == HCI_EVENT_SCO_CAN_SEND_NOW){
+                send_sco_data();
+            }
+            break;
+        default:
+            count++;
+            if ((count & SCO_REPORT_PERIOD)) return;
+            printf("SCO packets received: %u\n", count);
+            break;
+    }
 }
 
 static void packet_handler(uint8_t * event, uint16_t event_size){
diff --git a/src/hci.c b/src/hci.c
index 99e886c4c..a59b7b576 100644
--- a/src/hci.c
+++ b/src/hci.c
@@ -1816,7 +1816,7 @@ static void event_handler(uint8_t *packet, int size){
 
 static void sco_handler(uint8_t * packet, uint16_t size){
     if (!hci_stack->sco_packet_handler) return;
-    hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, packet, size);
+    hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
 }
 
 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
@@ -1844,14 +1844,14 @@ void hci_add_event_handler(btstack_packet_callback_registration_t * callback_han
 
 
 /** Register HCI packet handlers */
-void hci_register_acl_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
+void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
     hci_stack->acl_packet_handler = handler;
 }
 
 /**
  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
  */
-void hci_register_sco_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
+void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
     hci_stack->sco_packet_handler = handler;    
 }
 
@@ -2930,7 +2930,7 @@ static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
 
 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
     if (!hci_stack->acl_packet_handler) return;
-    hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, packet, size);
+    hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
 }
 
 static void hci_notify_if_sco_can_send_now(void){
@@ -2940,7 +2940,7 @@ static void hci_notify_if_sco_can_send_now(void){
         hci_stack->sco_waiting_for_can_send_now = 0;
         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
-        hci_stack->sco_packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
+        hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
     }
 }
 
diff --git a/src/hci.h b/src/hci.h
index b5febacad..df5c2fb8b 100644
--- a/src/hci.h
+++ b/src/hci.h
@@ -519,10 +519,10 @@ typedef struct {
     btstack_linked_list_t     connections;
 
     /* callback to L2CAP layer */
-    void (*acl_packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size);
+    btstack_packet_handler_t acl_packet_handler;
 
     /* callback for SCO data */
-    void (*sco_packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size);
+    btstack_packet_handler_t sco_packet_handler;
 
     /* callbacks for events */
     btstack_linked_list_t event_handlers;
@@ -720,12 +720,12 @@ void hci_add_event_handler(btstack_packet_callback_registration_t * callback_han
 /**
  * @brief Registers a packet handler for ACL data. Used by L2CAP
  */
-void hci_register_acl_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size));
+void hci_register_acl_packet_handler(btstack_packet_handler_t handler);
 
 /**
  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
  */
-void hci_register_sco_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size));
+void hci_register_sco_packet_handler(btstack_packet_handler_t handler);
 
 
 // Sending HCI Commands
diff --git a/src/l2cap.c b/src/l2cap.c
index ddc4f9121..0efef419c 100644
--- a/src/l2cap.c
+++ b/src/l2cap.c
@@ -82,7 +82,7 @@ static void l2cap_emit_channel_closed(l2cap_channel_t *channel);
 static void l2cap_emit_connection_request(l2cap_channel_t *channel);
 static int  l2cap_channel_ready_for_open(l2cap_channel_t *channel);
 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
-static void l2cap_acl_handler(uint8_t packet_type, uint8_t *packet, uint16_t size );
+static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size );
 static void l2cap_notify_channel_can_send(void);
 
 typedef struct l2cap_fixed_channel {
@@ -1381,7 +1381,7 @@ static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t *
     }
 }
 
-static void l2cap_acl_handler(uint8_t packet_type, uint8_t *packet, uint16_t size ){
+static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){
         
     // Get Channel ID
     uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 
@@ -1487,9 +1487,9 @@ static void l2cap_acl_handler(uint8_t packet_type, uint8_t *packet, uint16_t siz
 
         default: {
             // Find channel for this channel_id and connection handle
-            l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id);
+            l2cap_channel_t * l2cap_channel = l2cap_get_channel_for_local_cid(channel_id);
             if (channel) {
-                l2cap_dispatch_to_channel(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER);
+                l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER);
             }
             break;
         }
@@ -1499,7 +1499,7 @@ static void l2cap_acl_handler(uint8_t packet_type, uint8_t *packet, uint16_t siz
 }
 
 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE
-void l2cap_finialize_channel_close(l2cap_channel_t *channel){
+void l2cap_finialize_channel_close(l2cap_channel_t * channel){
     channel->state = L2CAP_STATE_CLOSED;
     l2cap_emit_channel_closed(channel);
     // discard channel