diff --git a/sys/net/sixlowpan/Jamfile b/sys/net/sixlowpan/Jamfile
index ea75100514..0304f037e7 100644
--- a/sys/net/sixlowpan/Jamfile
+++ b/sys/net/sixlowpan/Jamfile
@@ -2,7 +2,7 @@ SubDir TOP sys net sixlowpan ;
 
 # HDRS += $(TOP)/sys/net/sixlowpan/ ;
 
-Module 6lowpan : sixlowpan.c sixlowip.c sixlowmac.c sixlownd.c sixlowborder.c ieee802154_frame.c serialnumber.c semaphore.c ;
+Module 6lowpan : sixlowpan.c sixlowip.c sixlowmac.c sixlownd.c sixlowborder.c ieee802154_frame.c serialnumber.c semaphore.c flowcontrol.c ;
 
 UseModule vtimer ;
 UseModule transceiver ;
diff --git a/sys/net/sixlowpan/flowcontrol.c b/sys/net/sixlowpan/flowcontrol.c
new file mode 100644
index 0000000000..9e28ea7050
--- /dev/null
+++ b/sys/net/sixlowpan/flowcontrol.c
@@ -0,0 +1,157 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <vtimer.h>
+
+#include "semaphore.h"
+#include "bordermultiplex.h"
+
+flowcontrol_stat_t slwin_stat;
+sem_t connection_established;
+int16_t synack_seqnum = -1;
+
+
+ipv6_addr_t init_threeway_handshake() {
+    border_syn_packet_t *syn;
+    msg_t m;
+    m.content.ptr = NULL;
+    msg_send(&m,border_get_serial_reader(),1);
+    while(1) {
+        msg_receive(&m);
+        
+        syn = (border_syn_packet_t *)m.content.ptr;
+        border_conf_header_t *synack = (border_conf_header_t *)get_serial_out_buffer(0);
+        ipv6_addr_t addr;
+        memcpy(&addr, &(syn->addr), sizeof (ipv6_addr_t));
+        
+        slwin_stat.next_exp = syn->next_seq_num;
+        slwin_stat.last_frame = syn->next_exp - 1;
+        slwin_stat.last_ack = slwin_stat.last_frame;
+        
+        synack->reserved = 0;
+        synack->type = BORDER_PACKET_CONF_TYPE;
+        synack->conftype = BORDER_CONF_SYNACK;
+        
+        flowcontrol_send_over_uart((border_packet_t *)synack,sizeof (border_conf_header_t));
+        
+        synack_seqnum = synack->seq_num;
+        
+        return addr;
+    }
+}
+
+ipv6_addr_t flowcontrol_init() {
+    int i;
+    
+    slwin_stat.send_win_not_full = sem_init(BORDER_SWS);
+    for(i = 0; i < BORDER_SWS; i++) {
+        slwin_stat.send_win[i].frame_len = 0;
+    }
+    memset(&slwin_stat.send_win,0, sizeof(struct send_slot) * BORDER_SWS);
+        
+    for(i = 0; i < BORDER_RWS; i++) {
+        slwin_stat.recv_win[i].received = 0;
+        slwin_stat.recv_win[i].frame_len = 0;
+    }
+    memset(&slwin_stat.recv_win,0, sizeof(struct recv_slot) * BORDER_RWS);
+    
+    return init_threeway_handshake();
+}
+
+int set_timeout(vtimer_t *timeout, long useconds, void *args);
+
+void timeout_callback (void *args) {
+    uint8_t seq_num = *((uint8_t *)args);
+    struct send_slot *slot = &(slwin_stat.send_win[seq_num % BORDER_SWS]);
+    
+    if (seq_num == ((border_packet_t *)(slot->frame))->seq_num) {
+        writepacket(slot->frame,slot->frame_len);
+        
+        if (set_timeout(&slot->timeout, BORDER_SL_TIMEOUT, args) != 0) {
+            printf("ERROR: Error invoking timeout timer\n");
+            return;
+        }
+    } else {
+        return;
+    }
+}
+
+int set_timeout(vtimer_t *timeout, long useconds, void *args) {
+    timex_t interval;
+    interval.seconds = useconds / 1000000;
+    interval.nanoseconds = (useconds % 1000000) * 1000;
+    
+    return vtimer_set_cb(timeout, interval, timeout_callback, args);
+}
+
+static int in_window(uint8_t seq_num, uint8_t min, uint8_t max) {
+    uint8_t pos = seq_num - min;
+    uint8_t maxpos = max - min + 1;
+    return pos < maxpos;
+}
+
+void flowcontrol_send_over_uart(border_packet_t *packet, int len) {
+    struct send_slot *slot;
+    uint8_t args[] = {packet->seq_num};
+    
+    sem_wait(&(slwin_stat.send_win_not_full));
+    packet->seq_num = ++slwin_stat.last_frame;
+    slot = &(slwin_stat.send_win[packet->seq_num % BORDER_SWS]);
+    memcpy(slot->frame, (uint8_t *)packet, len);
+    slot->frame_len = len;
+    if (set_timeout(&slot->timeout, BORDER_SL_TIMEOUT, (void *)args) != 0) {
+        printf("ERROR: Error invoking timeout timer\n");
+        return;
+    }
+    writepacket((uint8_t *)packet, len);
+}
+
+void send_ack(uint8_t seq_num) {
+    border_packet_t *packet = (border_packet_t *)get_serial_out_buffer(0);
+    packet->reserved = 0;
+    packet->type = BORDER_PACKET_ACK_TYPE;
+    packet->seq_num = seq_num;
+    writepacket((uint8_t *)packet, sizeof (border_packet_t));
+}
+
+void flowcontrol_deliver_from_uart(border_packet_t *packet, int len) {
+    if (packet->type == BORDER_PACKET_ACK_TYPE) {
+        if (in_window(packet->seq_num, slwin_stat.last_ack+1, slwin_stat.last_frame)) {
+            if (synack_seqnum == packet->seq_num) {
+                synack_seqnum = -1;
+                sem_signal(&connection_established);
+            }
+            do {
+                struct send_slot *slot;
+                slot = &(slwin_stat.send_win[++slwin_stat.last_ack % BORDER_SWS]);
+                vtimer_remove(&slot->timeout);
+                memset(&slot->frame,0,BORDER_BUFFER_SIZE);
+                sem_signal(&slwin_stat.send_win_not_full);
+            } while (slwin_stat.last_ack != packet->seq_num);
+        }
+    } else {
+        struct recv_slot *slot;
+        
+        slot = &(slwin_stat.recv_win[packet->seq_num % BORDER_RWS]);
+        if (    !in_window(packet->seq_num, 
+                slwin_stat.next_exp, 
+                slwin_stat.next_exp + BORDER_RWS - 1)) {
+            return;
+        }
+        
+        memcpy(slot->frame, (uint8_t *)packet, len);
+        slot->received = 1;
+        
+        if (packet->seq_num == slwin_stat.next_exp) {
+            while (slot->received) {
+                demultiplex((border_packet_t *)slot->frame, slot->frame_len);
+                memset(&slot->frame,0,BORDER_BUFFER_SIZE);
+                slot->received = 0;
+                slot = &slwin_stat.recv_win[++(slwin_stat.next_exp) % BORDER_RWS];
+            }
+        }
+        
+        send_ack(slwin_stat.next_exp - 1);
+    }
+}
diff --git a/sys/net/sixlowpan/flowcontrol.h b/sys/net/sixlowpan/flowcontrol.h
new file mode 100644
index 0000000000..a016268992
--- /dev/null
+++ b/sys/net/sixlowpan/flowcontrol.h
@@ -0,0 +1,55 @@
+#ifndef FLOWCONTROL_H
+#define FLOWCONTROL_H
+
+#include <stdint.h>
+#include <vtimer.h>
+
+#include "semaphore.h"
+#include "sixlowip.h"
+#include "bordermultiplex.h"
+
+/* packet types for flowcontrol */
+#define BORDER_PACKET_ACK_TYPE    1
+
+/* configuration types for flowcontrol */
+#define BORDER_CONF_SYN           0
+#define BORDER_CONF_SYNACK        1
+
+#define BORDER_SWS                8
+#define BORDER_RWS                8
+#define BORDER_SL_TIMEOUT         500 // microseconds, maybe smaller
+
+typedef struct flowcontrol_stat_t {
+    /* Sender state */
+    uint8_t last_ack;
+    uint8_t last_frame;
+    sem_t send_win_not_full;
+    struct send_slot {
+        vtimer_t timeout; 
+        uint8_t frame[BORDER_BUFFER_SIZE];
+        size_t frame_len;
+    } send_win[BORDER_SWS];
+    
+    /* Receiver state */
+    uint8_t next_exp;
+    struct recv_slot {
+        int8_t received;
+        uint8_t frame[BORDER_BUFFER_SIZE];
+        size_t frame_len;
+    } recv_win[BORDER_RWS];
+} flowcontrol_stat_t;
+
+typedef struct __attribute__ ((packed)) border_syn_packet_t {
+    uint8_t reserved;
+    uint8_t type;
+    uint8_t next_seq_num;
+    uint8_t conftype;
+    uint8_t next_exp;
+    ipv6_addr_t addr;
+} border_syn_packet_t;
+
+ipv6_addr_t flowcontrol_init();
+void flowcontrol_send_over_uart(border_packet_t *packet, int len);
+void flowcontrol_deliver_from_uart(border_packet_t *packet, int len);
+
+#endif /* FLOWCONTROL_H*/
diff --git a/sys/net/sixlowpan/sixlowborder.c b/sys/net/sixlowpan/sixlowborder.c
index d8526e48af..d20c22a20e 100644
--- a/sys/net/sixlowpan/sixlowborder.c
+++ b/sys/net/sixlowpan/sixlowborder.c
@@ -1,7 +1,6 @@
 #include <stdint.h>
 #include <string.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <mutex.h>
 #include <thread.h>
 #include <msg.h>
@@ -9,6 +8,7 @@
 #include <posix_io.h>
 #include <board_uart0.h>
 #include "ieee802154_frame.h"
+#include "flowcontrol.h"
 #include "sixlowborder.h"
 #include "sixlowip.h"
 #include "sixlownd.h"
@@ -30,64 +30,11 @@ uint16_t serial_reader_pid;
 uint8_t serial_out_buf[BORDER_BUFFER_SIZE];
 uint8_t serial_in_buf[BORDER_BUFFER_SIZE];
 
-flowcontrol_stat_t slwin_stat;
-sem_t connection_established;
-int16_t synack_seqnum = -1;
-int readpacket(uint8_t *packet_buf, int size);
-
 void serial_reader_f(void);
-void flowcontrol_deliver_from_uart(border_packet_t *packet, int len);
-
-void slwin_init() {
-    int i;
-    
-    slwin_stat.send_win_not_full = sem_init(BORDER_SWS);
-    for(i = 0; i < BORDER_SWS; i++) {
-        slwin_stat.send_win[i].frame_len = 0;
-    }
-    memset(&slwin_stat.send_win,0, sizeof(struct send_slot) * BORDER_SWS);
-        
-    for(i = 0; i < BORDER_RWS; i++) {
-        slwin_stat.recv_win[i].received = 0;
-        slwin_stat.recv_win[i].frame_len = 0;
-    }
-    memset(&slwin_stat.recv_win,0, sizeof(struct recv_slot) * BORDER_RWS);
-}
-
-ipv6_addr_t init_threeway_handshake() {
-    border_syn_packet_t *syn;
-    msg_t m;
-    m.content.ptr = NULL;
-    msg_send(&m,serial_reader_pid,1);
-    while(1) {
-        msg_receive(&m);
-        
-        syn = (border_syn_packet_t *)m.content.ptr;
-        border_conf_header_t *synack = (border_conf_header_t *)get_serial_out_buffer(0);
-        ipv6_addr_t addr;
-        memcpy(&addr, &(syn->addr), sizeof (ipv6_addr_t));
-        
-        slwin_stat.next_exp = syn->next_seq_num;
-        slwin_stat.last_frame = syn->next_exp - 1;
-        slwin_stat.last_ack = slwin_stat.last_frame;
-        
-        synack->reserved = 0;
-        synack->type = BORDER_PACKET_CONF_TYPE;
-        synack->conftype = BORDER_CONF_SYNACK;
-        
-        flowcontrol_send_over_uart((border_packet_t *)synack,sizeof (border_conf_header_t));
-        
-        synack_seqnum = synack->seq_num;
-        
-        return addr;
-    }
-}
 
 uint8_t border_initialize(transceiver_type_t trans,ipv6_addr_t *border_router_addr) {
     ipv6_addr_t addr;
     
-    slwin_init();
-    
     serial_reader_pid = thread_create(
             serial_reader_stack, READER_STACK_SIZE,
             PRIORITY_MAIN-1, CREATE_STACKTEST,
@@ -96,7 +43,7 @@ uint8_t border_initialize(transceiver_type_t trans,ipv6_addr_t *border_router_ad
     if (border_router_addr == NULL) {
         border_router_addr = &addr;
         
-        addr = init_threeway_handshake();
+        addr = flowcontrol_init();
     }
     
     /* only allow addresses generated accoding to 
@@ -270,38 +217,6 @@ void serial_reader_f(void) {
     }
 }
 
-int set_timeout(vtimer_t *timeout, long useconds, void *args);
-
-void timeout_callback (void *args) {
-    uint8_t seq_num = *((uint8_t *)args);
-    struct send_slot *slot = &(slwin_stat.send_win[seq_num % BORDER_SWS]);
-    
-    if (seq_num == ((border_packet_t *)(slot->frame))->seq_num) {
-        writepacket(slot->frame,slot->frame_len);
-        
-        if (set_timeout(&slot->timeout, BORDER_SL_TIMEOUT, args) != 0) {
-            printf("ERROR: Error invoking timeout timer\n");
-            return;
-        }
-    } else {
-        return;
-    }
-}
-
-int set_timeout(vtimer_t *timeout, long useconds, void *args) {
-    timex_t interval;
-    interval.seconds = useconds / 1000000;
-    interval.nanoseconds = (useconds % 1000000) * 1000;
-    
-    return vtimer_set_cb(timeout, interval, timeout_callback, args);
-}
-
-static int in_window(uint8_t seq_num, uint8_t min, uint8_t max) {
-    uint8_t pos = seq_num - min;
-    uint8_t maxpos = max - min + 1;
-    return pos < maxpos;
-}
-
 void demultiplex(border_packet_t *packet, int len) {
     switch (packet->type) {
         case (BORDER_PACKET_RAW_TYPE):{
@@ -359,71 +274,6 @@ void demultiplex(border_packet_t *packet, int len) {
     }
 }
 
-void border_send_ack(uint8_t seq_num) {
-    border_packet_t *packet = (border_packet_t *)get_serial_out_buffer(0);
-    packet->reserved = 0;
-    packet->type = BORDER_PACKET_ACK_TYPE;
-    packet->seq_num = seq_num;
-    writepacket((uint8_t *)packet, sizeof (border_packet_t));
-}
-
-void flowcontrol_deliver_from_uart(border_packet_t *packet, int len) {
-    if (packet->type == BORDER_PACKET_ACK_TYPE) {
-        if (in_window(packet->seq_num, slwin_stat.last_ack+1, slwin_stat.last_frame)) {
-            if (synack_seqnum == packet->seq_num) {
-                synack_seqnum = -1;
-                sem_signal(&connection_established);
-            }
-            do {
-                struct send_slot *slot;
-                slot = &(slwin_stat.send_win[++slwin_stat.last_ack % BORDER_SWS]);
-                vtimer_remove(&slot->timeout);
-                memset(&slot->frame,0,BORDER_BUFFER_SIZE);
-                sem_signal(&slwin_stat.send_win_not_full);
-            } while (slwin_stat.last_ack != packet->seq_num);
-        }
-    } else {
-        struct recv_slot *slot;
-        
-        slot = &(slwin_stat.recv_win[packet->seq_num % BORDER_RWS]);
-        if (    !in_window(packet->seq_num, 
-                slwin_stat.next_exp, 
-                slwin_stat.next_exp + BORDER_RWS - 1)) {
-            return;
-        }
-        
-        memcpy(slot->frame, (uint8_t *)packet, len);
-        slot->received = 1;
-        
-        if (packet->seq_num == slwin_stat.next_exp) {
-            while (slot->received) {
-                demultiplex((border_packet_t *)slot->frame, slot->frame_len);
-                memset(&slot->frame,0,BORDER_BUFFER_SIZE);
-                slot->received = 0;
-                slot = &slwin_stat.recv_win[++(slwin_stat.next_exp) % BORDER_RWS];
-            }
-        }
-        
-        border_send_ack(slwin_stat.next_exp - 1);
-    }
-}
-
-void flowcontrol_send_over_uart(border_packet_t *packet, int len) {
-    struct send_slot *slot;
-    uint8_t args[] = {packet->seq_num};
-    
-    sem_wait(&(slwin_stat.send_win_not_full));
-    packet->seq_num = ++slwin_stat.last_frame;
-    slot = &(slwin_stat.send_win[packet->seq_num % BORDER_SWS]);
-    memcpy(slot->frame, (uint8_t *)packet, len);
-    slot->frame_len = len;
-    if (set_timeout(&slot->timeout, BORDER_SL_TIMEOUT, (void *)args) != 0) {
-        printf("ERROR: Error invoking timeout timer\n");
-        return;
-    }
-    writepacket((uint8_t *)packet, len);
-}
-
 void multiplex_send_ipv6_over_uart(struct ipv6_hdr_t *packet) {
     border_l3_header_t *serial_buf;
     
diff --git a/sys/net/sixlowpan/sixlowborder.h b/sys/net/sixlowpan/sixlowborder.h
index 8e93072835..353c90a801 100644
--- a/sys/net/sixlowpan/sixlowborder.h
+++ b/sys/net/sixlowpan/sixlowborder.h
@@ -5,27 +5,17 @@
 
 #include <stdint.h>
 #include <mutex.h>
-#include <vtimer.h>
 #include "sixlowip.h"
 #include "sixlowpan.h"
 #include "sixlownd.h"
 #include "semaphore.h"
 
-#define BORDER_SWS                8
-#define BORDER_RWS                8
-#define BORDER_SL_TIMEOUT         500 // microseconds, maybe smaller
-
-#define BORDER_HEADER_LENGTH      2
-
 /* packet types of uart-packets */
 #define BORDER_PACKET_RAW_TYPE    0
-#define BORDER_PACKET_ACK_TYPE    1
 #define BORDER_PACKET_CONF_TYPE   2
 #define BORDER_PACKET_L3_TYPE     3
 
 /* configuration types */
-#define BORDER_CONF_SYN           0
-#define BORDER_CONF_SYNACK        1
 #define BORDER_CONF_CONTEXT       2
 #define BORDER_CONF_IPADDR        3
 
@@ -52,15 +42,6 @@ typedef struct __attribute__ ((packed)) border_conf_header_t {
     uint8_t conftype;
 } border_conf_header_t;
 
-typedef struct __attribute__ ((packed)) border_syn_packet_t {
-    uint8_t reserved;
-    uint8_t type;
-    uint8_t next_seq_num;
-    uint8_t conftype;
-    uint8_t next_exp;
-    ipv6_addr_t addr;
-} border_syn_packet_t;
-
 typedef struct __attribute__ ((packed)) border_addr_packet_t {
     uint8_t reserved;
     uint8_t type;
@@ -85,34 +66,18 @@ typedef struct __attribute__ ((packed)) border_context_packet_t {
 
 #define BORDER_BUFFER_SIZE (sizeof (border_l3_header_t) + MTU)
 
-typedef struct flowcontrol_stat_t {
-    /* Sender state */
-    uint8_t last_ack;
-    uint8_t last_frame;
-    sem_t send_win_not_full;
-    struct send_slot {
-        vtimer_t timeout; 
-        uint8_t frame[BORDER_BUFFER_SIZE];
-        size_t frame_len;
-    } send_win[BORDER_SWS];
-    
-    /* Receiver state */
-    uint8_t next_exp;
-    struct recv_slot {
-        int8_t received;
-        uint8_t frame[BORDER_BUFFER_SIZE];
-        size_t frame_len;
-    } recv_win[BORDER_RWS];
-} flowcontrol_stat_t;
 uint16_t border_get_serial_reader();
 uint8_t *get_serial_out_buffer(int offset);
 uint8_t *get_serial_in_buffer(int offset);
 
 uint8_t border_initialize(transceiver_type_t trans,ipv6_addr_t *border_router_addr);
+void demultiplex(border_packet_t *packet, int len);
 void multiplex_send_ipv6_over_uart(struct ipv6_hdr_t *packet);
 void multiplex_send_addr_over_uart(ipv6_addr_t *addr);
-void flowcontrol_send_over_uart(border_packet_t *packet, int len);
 void border_send_ipv6_over_lowpan(struct ipv6_hdr_t *packet, uint8_t aro_flag, uint8_t sixco_flag);
 void border_process_lowpan(void);
 
+int readpacket(uint8_t *packet_buf, int size);
+int writepacket(uint8_t *packet_buf, size_t size);
+
 #endif /* SIXLOWBORDER_H*/