diff --git a/openair2/LAYER2/PROTO_AGENT/proto_agent_defs.h b/openair2/LAYER2/PROTO_AGENT/proto_agent_defs.h
index 0e0302002c..8857a498ef 100644
--- a/openair2/LAYER2/PROTO_AGENT/proto_agent_defs.h
+++ b/openair2/LAYER2/PROTO_AGENT/proto_agent_defs.h
@@ -100,8 +100,6 @@ typedef uint8_t mod_id_t;  // module or enb id
 typedef uint8_t lcid_t;
 typedef int32_t err_code_t;
 
-#define CHANNEL_UDP 1
-
 typedef struct {
   /* general info */ 
  
diff --git a/openair2/UTIL/ASYNC_IF/link_manager.c b/openair2/UTIL/ASYNC_IF/link_manager.c
index 82fe142237..f355e79dd9 100644
--- a/openair2/UTIL/ASYNC_IF/link_manager.c
+++ b/openair2/UTIL/ASYNC_IF/link_manager.c
@@ -47,7 +47,7 @@ static void *link_manager_sender_thread(void *_manager)
 
   while (manager->run) {
     while (message_get(manager->send_queue, &data, &size, &priority) == 0) {
-      link_send_packet(manager->socket_link, data, size, manager->type, manager->peer_addr, manager->port);
+      link_send_packet(manager->socket_link, data, size, manager->peer_addr, manager->port);
       free(data);
     }
     //    if (message_get(manager->send_queue, &data, &size, &priority))
@@ -76,7 +76,7 @@ static void *link_manager_receiver_thread(void *_manager)
   LOG_D(MAC, "starting link manager receiver thread\n");
 
   while (manager->run) {
-    if (link_receive_packet(manager->socket_link, &data, &size, manager->type))
+    if (link_receive_packet(manager->socket_link, &data, &size))
       goto error;
     /* todo: priority */
     if (message_put(manager->receive_queue, data, size, 0))
diff --git a/openair2/UTIL/ASYNC_IF/socket_link.c b/openair2/UTIL/ASYNC_IF/socket_link.c
index d8dcb764e9..7bd5d4eea9 100644
--- a/openair2/UTIL/ASYNC_IF/socket_link.c
+++ b/openair2/UTIL/ASYNC_IF/socket_link.c
@@ -68,6 +68,7 @@ socket_link_t *new_link_server(int port)
     LOG_E(MAC, "%s:%d: socket: %s\n", __FILE__, __LINE__, strerror(errno));
     goto error;
   }
+  ret->type = SOCK_STREAM;
 
   reuse = 1;
   if (setsockopt(socket_server, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) == -1) {
@@ -135,6 +136,7 @@ socket_link_t *new_link_client(const char *server, int port)
     LOG_E(MAC, "%s:%d: socket: %s\n", __FILE__, __LINE__, strerror(errno));
     goto error;
   }
+  ret->type = SOCK_STREAM;
 
   no_delay = 1;
   if (setsockopt(ret->socket_fd, SOL_TCP, TCP_NODELAY, &no_delay, sizeof(no_delay)) == -1) {
@@ -183,6 +185,7 @@ socket_link_t *new_link_udp_server(const char *bind_addr, int bind_port)
   if ((socket_server=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
     goto error;
   }
+  ret->type = SOCK_DGRAM;
 
   // zero out the structure
   memset((char *) &si_me, 0, sizeof(si_me));
@@ -231,6 +234,7 @@ socket_link_t *new_link_udp_client(const char *server, int port){
   if ( (s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1){
         goto error;
   }
+  ret->type = SOCK_DGRAM;
  
   memset((char *) &si_other, 0, sizeof(si_other));
   si_other.sin_family = AF_INET;
@@ -302,6 +306,7 @@ socket_link_t *new_link_sctp_server(int port)
   ret->socket_fd = -1;
 
   ret->socket_fd = accept (listenSock, NULL, NULL);
+  ret->type = SOCK_STREAM;
   
   return ret;
 
@@ -334,6 +339,7 @@ socket_link_t *new_link_sctp_client(const char *server, int port)
       perror("socket()");
       exit(1);
   }
+  ret->type = SOCK_STREAM;
  
   bzero ((void *) &servaddr, sizeof (servaddr));
   servaddr.sin_family = AF_INET;
@@ -469,57 +475,54 @@ socket_closed:
 /*
  * return -1 on error and 0 if the sending was fine
  */
-int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_type, const char *peer_addr, int peer_port)
+int link_send_packet(socket_link_t *link, void *data, int size, const char *peer_addr, int peer_port)
 {
   char sizebuf[4];
   int32_t s = size;
-
-  if ((proto_type == 0) || (proto_type == 2))
-  {
+  switch (link->type) {
+  case SOCK_STREAM:
     /* send the size first, maximum is 2^31 bytes */
     sizebuf[0] = (s >> 24) & 255;
     sizebuf[1] = (s >> 16) & 255;
     sizebuf[2] = (s >> 8) & 255;
     sizebuf[3] = s & 255;
     if (socket_send(link->socket_fd, sizebuf, 4) == -1)
-      goto error;
+      return -1;
 
     link->bytes_sent += 4;
 
     if (socket_send(link->socket_fd, data, size) == -1)
-      goto error;
-
-  }
-  else if (proto_type == 1 )
-  {
+      return -1;
+    break;
+  case SOCK_DGRAM:
     /* UDP is connectionless -> only send the data */
     if (socket_udp_send(link->socket_fd, data, size, peer_addr, peer_port) == -1)
-      goto error;
-
+      return -1;
+    break;
+  default:
+    LOG_E(MAC, "unknown socket type %d\n", link->type);
+    return -1;
   }
 
   link->bytes_sent += size;
   link->packets_sent++;
 
   return 0;
-
-error:
-  return -1;
 }
 
 /*
  * return -1 on error and 0 if the sending was fine
  */
 
-int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size, uint16_t proto_type)
+int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size)
 {
   unsigned char sizebuf[4];
   int32_t       size = 0;
   void          *data = NULL;
   
   /* received the size first, maximum is 2^31 bytes */
-  if ((proto_type == 0) || (proto_type == 2))
-  {
+  switch (link->type) {
+  case SOCK_STREAM:
     if (socket_receive(link->socket_fd, sizebuf, 4) == -1)
       goto error;
 
@@ -538,9 +541,8 @@ int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size, uin
 
     if (socket_receive(link->socket_fd, data, size) == -1)
       goto error;
-  }
-  else if (proto_type == 1)
-  {
+    break;
+  case SOCK_DGRAM:
     /* we get a single packet (no size, UDP could lose it). Therefore, prepare
      * for the maximum UDP packet size */
     size = 65535;
@@ -553,6 +555,10 @@ int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size, uin
     size = socket_udp_receive(link->socket_fd, data, size);
     if (size < 0)
       goto error;
+    break;
+  default:
+    LOG_E(MAC, "unknown socket type %d\n", link->type);
+    goto error;
   }
 
   link->bytes_received += size;
diff --git a/openair2/UTIL/ASYNC_IF/socket_link.h b/openair2/UTIL/ASYNC_IF/socket_link.h
index a7a83f66c6..b466721e08 100644
--- a/openair2/UTIL/ASYNC_IF/socket_link.h
+++ b/openair2/UTIL/ASYNC_IF/socket_link.h
@@ -37,9 +37,10 @@
 extern "C" {
 #endif
 
+
 typedef struct {
   int      socket_fd;
-  int      peer_port;
+  int      type;
   uint64_t bytes_sent;
   uint64_t packets_sent;
   uint64_t bytes_received;
@@ -53,8 +54,8 @@ socket_link_t *new_link_udp_server(const char *bind_addr, int bind_port);
 socket_link_t *new_link_udp_client(const char *server, int port);
 socket_link_t *new_link_sctp_server(int port);
 socket_link_t *new_link_sctp_client(const char *server, int port);
-int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_type, const char *peer_addr, int port);
-int link_receive_packet(socket_link_t *link, void **data, int *size, uint16_t proto_type);
+int link_send_packet(socket_link_t *link, void *data, int size, const char *peer_addr, int port);
+int link_receive_packet(socket_link_t *link, void **data, int *size);
 int close_link(socket_link_t *link);