diff --git a/scapy/contrib/cansocket_native.uts b/scapy/contrib/cansocket_native.uts
index 3c422a52392..482c27f4745 100644
--- a/scapy/contrib/cansocket_native.uts
+++ b/scapy/contrib/cansocket_native.uts
@@ -59,6 +59,7 @@ thread = threading.Thread(target=sender)
 thread.start()
 rx = sock1.recv()
 rx == CAN(identifier=0x7ff,length=1,data=b'\x01')
+thread.join()
 
 = CAN Socket send recv
 ~ needs_root linux
@@ -73,6 +74,7 @@ thread = threading.Thread(target=sender)
 thread.start()
 rx = sock1.recv()
 rx == CAN(identifier=0x7ff,length=8,data=b'\x01\x02\x03\x04\x05\x06\x07\x08')
+thread.join()
 
 = CAN Socket basecls test
 ~ needs_root linux
@@ -89,6 +91,7 @@ thread.start()
 rx = sock1.recv()
 rx == Raw(bytes(CAN(identifier=0x7ff,length=8,data=b'\x01\x02\x03\x04\x05\x06\x07\x08')))
 sock1.basecls = CAN
+thread.join()
 
 + Advanced Socket Tests()
 = CAN Socket sr1
@@ -114,6 +117,7 @@ rx = sock1.sr1(tx)
 rx == tx
 
 sock1.close()
+thread.join()
 
 = CAN Socket sr1 time check
 ~ needs_root linux
@@ -142,7 +146,7 @@ rx = None
 rx = srcan(tx, "vcan0", timeout=1)
 rx = rx[0][0][1]
 tx == rx
-
+thread.join()
 
 = srcan check init time basecls
 ~ needs_root linux
@@ -159,6 +163,7 @@ rx = None
 rx = srcan(tx, "vcan0", timeout=1, basecls=Raw)
 rx = rx[0][0][1]
 Raw(bytes(tx)) == rx
+thread.join()
 
 = srcan check rx and tx
 ~ needs_root linux
@@ -171,7 +176,6 @@ tx.sent_time > 0 and rx.time > 0 and tx.sent_time < rx.time
 sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x200, 'can_mask': 0x7ff}])
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface="vcan0")
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x300, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -182,11 +186,11 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
 len(packets) == 3
 
 sock1.close()
+thread.join()
 
 = sniff with filtermask 0x700
 ~ needs_root linux
@@ -194,7 +198,6 @@ sock1.close()
 sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x200, 'can_mask': 0x700}])
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface="vcan0")
     sock2.send(CAN(identifier=0x212, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x300, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -205,11 +208,11 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
+thread.join()
 
 = sniff with filtermask 0x0ff
 ~ needs_root linux
@@ -217,7 +220,6 @@ sock1.close()
 sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x200, 'can_mask': 0x0ff}])
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface="vcan0")
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x301, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -228,11 +230,11 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
+thread.join()
 
 = sniff with multiple filters
 ~ needs_root linux
@@ -240,7 +242,6 @@ sock1.close()
 sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x200, 'can_mask': 0x7ff}, {'can_id': 0x400, 'can_mask': 0x7ff}, {'can_id': 0x600, 'can_mask': 0x7ff},  {'can_id': 0x7ff, 'can_mask': 0x7ff}])
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface="vcan0")
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x300, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -252,11 +253,11 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
+thread.join()
 
 = sniff with filtermask 0x7ff and inverse filter
 ~ needs_root linux
@@ -264,7 +265,6 @@ sock1.close()
 sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x200 | CAN_INV_FILTER, 'can_mask': 0x7ff}])
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface="vcan0")
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -275,11 +275,11 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
 len(packets) == 2
 
 sock1.close()
+thread.join()
 
 = sniff with filtermask 0x1FFFFFFF
 ~ needs_root linux
@@ -287,7 +287,6 @@ sock1.close()
 sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x10000000, 'can_mask': 0x1fffffff}])
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface="vcan0")
     sock2.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -298,11 +297,11 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
 len(packets) == 2
 
 sock1.close()
+thread.join()
 
 = sniff with filtermask 0x1FFFFFFF and inverse filter
 ~ needs_root linux
@@ -311,8 +310,7 @@ sock1 = CANSocket(iface='vcan0', can_filters=[{'can_id': 0x10000000 | CAN_INV_FI
 
 if six.PY3:
     thread = threading.Thread(target=sender)
-    thread.start()
-    packets = sock1.sniff(timeout=0.3)
+    packets = sock1.sniff(timeout=0.2, started_callback=thread.start)
     len(packets) == 4
 
 sock1.close()
@@ -349,7 +347,6 @@ sock0 = CANSocket(iface='vcan0')
 sock1 = CANSocket(iface='vcan1')
 
 def senderVCan0():
-    sleep(0.1)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -357,25 +354,30 @@ def senderVCan0():
     sock0.send(CAN(flags='extended', identifier=0x10040000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
 
+bridgeStarted = threading.Event()
+
 def bridge():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface='vcan1')
     def pnr(pkt):
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
 threadSender = threading.Thread(target=senderVCan0)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
-len(packetsVCan0) == 0
+packetsVCan1 = sock1.sniff(timeout=0.2, started_callback=threadSender.start)
 len(packetsVCan1) == 6
 
+threadSender.join()
+threadBridge.join()
+
 sock1.close()
 sock0.close()
 
@@ -386,36 +388,38 @@ sock0 = CANSocket(iface='vcan0')
 sock1 = CANSocket(iface='vcan1')
 
 def senderVCan1():
-    sleep(0.1)
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x80, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
+
 def bridge():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface='vcan1')
     def pnr(pkt):
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan1)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.2, started_callback=threadSender.start)
 len(packetsVCan0) == 4
-len(packetsVCan1) == 0
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan0 vcan1 package forwarding both directions
 ~ needs_root linux
 
@@ -423,7 +427,6 @@ sock0 = CANSocket(iface='vcan0')
 sock1 = CANSocket(iface='vcan1')
 
 def senderBothVCans():
-    sleep(0.2)
     sock0.send(CAN(flags='extended', identifier=0x25, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x20, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x25, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -435,30 +438,37 @@ def senderBothVCans():
     sock1.send(CAN(flags='extended', identifier=0x80, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x40, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
+
 def bridge():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface='vcan1')
     def pnr(pkt):
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderBothVCans)
-threadSender.start()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+bridgeStarted.wait()
+
+packetsVCan0 = sock0.sniff(timeout=0.1, count=6, started_callback=threadSender.start)
+packetsVCan1 = sock1.sniff(timeout=0.1)
+
 len(packetsVCan0) == 4
 len(packetsVCan1) == 6
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan1 package change
 ~ needs_root linux
 
@@ -474,32 +484,36 @@ def senderVCan0():
     sock0.send(CAN(flags='extended', identifier=0x10040000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
 
+bridgeStarted = threading.Event()
+
 def bridgeWithPackageChangeVCan0ToVCan1():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface="vcan1")
     def pnr(pkt):
         pkt.data = b'\x08\x07\x06\x05\x04\x03\x02\x01'
         pkt.identifier = 0x10010000
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithPackageChangeVCan0ToVCan1)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan0)
-threadSender.start()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
-len(packetsVCan0) == 0
+bridgeStarted.wait()
+
+packetsVCan1 = sock1.sniff(timeout=0.2,  started_callback=threadSender.start)
 len(packetsVCan1) == 6
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan0 package change
 ~ needs_root linux
 
@@ -513,32 +527,36 @@ def senderVCan1():
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
+
 def bridgeWithPackageChangeVCan1ToVCan0():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface="vcan1")
     def pnr(pkt):
         pkt.data = b'\x08\x07\x06\x05\x04\x03\x02\x01'
         pkt.identifier = 0x10010000
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithPackageChangeVCan1ToVCan0)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan1)
-threadSender.start()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+bridgeStarted.wait()
+
+packetsVCan0 = sock0.sniff(timeout=0.2,  started_callback=threadSender.start)
 len(packetsVCan0) == 4
-len(packetsVCan1) == 0
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan0 and vcan1 package change in both directions
 ~ needs_root linux
 
@@ -546,7 +564,6 @@ sock0 = CANSocket(iface='vcan0',  can_filters=[{'can_id': 0x10010000, 'can_mask'
 sock1 = CANSocket(iface='vcan1', can_filters=[{'can_id': 0x10010000, 'can_mask': 0x1fffffff}])
 
 def senderBothVCans():
-    sleep(0.2)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -558,32 +575,39 @@ def senderBothVCans():
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
+
 def bridgeWithPackageChangeBothDirections():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface="vcan1")
     def pnr(pkt):
         pkt.data = b'\x08\x07\x06\x05\x04\x03\x02\x01'
         pkt.identifier = 0x10010000
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithPackageChangeBothDirections)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderBothVCans)
+
+bridgeStarted.wait()
 threadSender.start()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.1)
+packetsVCan1 = sock1.sniff(timeout=0.1)
 len(packetsVCan0) == 4
 len(packetsVCan1) == 6
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan0 package remove
 ~ needs_root linux
 
@@ -591,7 +615,6 @@ sock0 = CANSocket(iface='vcan0')
 sock1 = CANSocket(iface='vcan1')
 
 def senderVCan0():
-    sleep(0.1)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -599,7 +622,10 @@ def senderVCan0():
     sock0.send(CAN(flags='extended', identifier=0x10040000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
 
+bridgeStarted = threading.Event()
+
 def bridgeWithRemovePackageFromVCan0ToVCan1():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface="vcan1")
     def pnr(pkt):
@@ -608,26 +634,28 @@ def bridgeWithRemovePackageFromVCan0ToVCan1():
         else:
             pkt = pkt
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithRemovePackageFromVCan0ToVCan1)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan0)
-threadSender.start()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+bridgeStarted.wait()
 
-len(packetsVCan0) == 0
+threadSender.start()
+
+packetsVCan1 = sock1.sniff(timeout=0.2)
 len(packetsVCan1) == 5
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan1 package remove
 ~ needs_root linux
 
@@ -635,13 +663,15 @@ sock0 = CANSocket(iface='vcan0')
 sock1 = CANSocket(iface='vcan1')
 
 def senderVCan1():
-    sleep(0.1)
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
+
 def bridgeWithRemovePackageFromVCan1ToVCan0():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface="vcan1")
     def pnr(pkt):
@@ -650,26 +680,27 @@ def bridgeWithRemovePackageFromVCan1ToVCan0():
         else:
             pkt = pkt
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithRemovePackageFromVCan1ToVCan0)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan1)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+threadSender.start()
 
+packetsVCan0 = sock0.sniff(timeout=0.2)
 len(packetsVCan0) == 3
-len(packetsVCan1) == 0
 
 sock0.close()
 sock1.close()
 
+threadSender.join()
+threadBridge.join()
+
 =bridge and sniff setup vcan0 and vcan1 package remove both directions
 ~ needs_root linux
 
@@ -677,7 +708,6 @@ sock0 = CANSocket(iface="vcan0")
 sock1 = CANSocket(iface="vcan1")
 
 def senderBothVCans():
-    sleep(0.2)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -689,7 +719,10 @@ def senderBothVCans():
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
+
 def bridgeWithRemovePackageInBothDirections():
+    global bridgeStarted
     bSock0 = CANSocket(iface="vcan0")
     bSock1 = CANSocket(iface="vcan1")
     def pnrA(pkt):
@@ -704,22 +737,25 @@ def bridgeWithRemovePackageInBothDirections():
         else:
             pkt = pkt
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnrA, xfrm21=pnrB, timeout=0.5)
+    bridgeStarted.set()
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnrA, xfrm21=pnrB, timeout=0.2)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithRemovePackageInBothDirections)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderBothVCans)
-threadSender.start()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+bridgeStarted.wait()
+
+packetsVCan0 = sock0.sniff(timeout=0.1, started_callback=threadSender.start)
+packetsVCan1 = sock1.sniff(timeout=0.1)
 
 len(packetsVCan0) == 3
 len(packetsVCan1) == 5
 
 sock0.close()
-sock1.close()
\ No newline at end of file
+sock1.close()
+
+threadSender.join()
+threadBridge.join()
\ No newline at end of file
diff --git a/scapy/contrib/cansocket_python_can.uts b/scapy/contrib/cansocket_python_can.uts
index 88f403e2995..8ff1a472816 100644
--- a/scapy/contrib/cansocket_python_can.uts
+++ b/scapy/contrib/cansocket_python_can.uts
@@ -59,7 +59,6 @@ sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
 ~ linux
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x7ff,length=1,data=b'\x01'))
     sock2.close()
@@ -76,7 +75,6 @@ rx == CAN(identifier=0x7ff,length=1,data=b'\x01')
 ~ needs_root linux
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x7ff,length=8,data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.close()
@@ -93,7 +91,6 @@ sock1.basecls = CAN
 ~ linux
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x7ff,length=8,data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.close()
@@ -113,7 +110,6 @@ sock1.close()
 sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000, can_filters=[{'can_id': 0x200, 'can_mask': 0x7ff}]))
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x300, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -124,9 +120,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 3
 
 sock1.close()
@@ -138,7 +133,6 @@ sock1.close()
 sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000, can_filters=[{'can_id': 0x200, 'can_mask': 0x700}]))
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x212, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x300, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -149,9 +143,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
@@ -163,7 +156,6 @@ sock1.close()
 sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000, can_filters=[{'can_id': 0x200, 'can_mask': 0xff}]))
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x301, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -174,9 +166,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
@@ -192,7 +183,6 @@ sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                                      {'can_id': 0x7ff, 'can_mask': 0x7ff}]))
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x300, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -204,9 +194,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
@@ -219,7 +208,6 @@ sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                           can_filters=[{'can_id': 0x200 | CAN_INV_FILTER, 'can_mask': 0x7ff}]))
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(identifier=0x200, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -230,9 +218,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 2
 
 sock1.close()
@@ -245,7 +232,6 @@ sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                           can_filters=[{'can_id': 0x10000000, 'can_mask': 0x1fffffff}]))
 
 def sender():
-    sleep(0.1)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -256,9 +242,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 2
 
 sock1.close()
@@ -271,7 +256,6 @@ sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                           can_filters=[{'can_id': 0x10000000 | CAN_INV_FILTER, 'can_mask': 0x1fffffff}]))
 
 def sender():
-    sleep(0.2)
     sock2 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0', bitrate=250000))
     sock2.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock2.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -282,9 +266,8 @@ def sender():
     sock2.close()
 
 thread = threading.Thread(target=sender)
-thread.start()
 
-packets = sock1.sniff(timeout=0.3)
+packets = sock1.sniff(timeout=0.1, started_callback=thread.start)
 len(packets) == 4
 
 sock1.close()
@@ -334,7 +317,6 @@ sock0 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
 sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan1', bitrate=250000))
 
 def senderVCan0():
-    sleep(0.1)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -342,7 +324,9 @@ def senderVCan0():
     sock0.send(CAN(flags='extended', identifier=0x10040000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -351,23 +335,26 @@ def bridge():
                                 bitrate=250000))
     def pnr(pkt):
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
 threadSender = threading.Thread(target=senderVCan0)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
-len(packetsVCan0) == 0
+packetsVCan1 = sock1.sniff(timeout=0.3, started_callback=threadSender.start)
 len(packetsVCan1) == 6
 
 sock1.close()
 sock0.close()
 
+threadBridge.join()
+threadSender.join()
+
 = bridge and sniff setup vcan0 package forwarding
 ~ needs_root linux
 
@@ -375,13 +362,14 @@ sock0 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
 sock1 = CANSocket(iface=can.interface.Bus(bustype='socketcan', channel='vcan1', bitrate=250000))
 
 def senderVCan1():
-    sleep(0.1)
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x80, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -390,25 +378,26 @@ def bridge():
                                 bitrate=250000))
     def pnr(pkt):
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan1)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.3, started_callback=threadSender.start)
 len(packetsVCan0) == 4
-len(packetsVCan1) == 0
 
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
 =bridge and sniff setup vcan0 vcan1 package forwarding both directions
 ~ needs_root linux
 
@@ -421,7 +410,6 @@ sock1 = CANSocket(
 
 
 def senderBothVCans():
-    sleep(0.2)
     sock0.send(CAN(flags='extended', identifier=0x25, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x20, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x25, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -433,7 +421,9 @@ def senderBothVCans():
     sock1.send(CAN(flags='extended', identifier=0x80, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x40, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -442,18 +432,18 @@ def bridge():
                                 bitrate=250000))
     def pnr(pkt):
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderBothVCans)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.3, started_callback=threadSender.start)
 packetsVCan1 = sock1.sniff(timeout=0.3)
 len(packetsVCan0) == 4
 len(packetsVCan1) == 6
@@ -461,6 +451,9 @@ len(packetsVCan1) == 6
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
 =bridge and sniff setup vcan1 package change
 ~ needs_root linux
 
@@ -472,7 +465,6 @@ sock1 = CANSocket(
                                 bitrate=250000, can_filters=[{'can_id': 0x10010000, 'can_mask': 0x1fffffff}]))
 
 def senderVCan0():
-    sleep(0.1)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -480,7 +472,9 @@ def senderVCan0():
     sock0.send(CAN(flags='extended', identifier=0x10040000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
 
+bridgeStarted = threading.Event()
 def bridgeWithPackageChangeVCan0ToVCan1():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -491,25 +485,26 @@ def bridgeWithPackageChangeVCan0ToVCan1():
         pkt.data = b'\x08\x07\x06\x05\x04\x03\x02\x01'
         pkt.identifier = 0x10010000
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithPackageChangeVCan0ToVCan1)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan0)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
-len(packetsVCan0) == 0
+packetsVCan1 = sock1.sniff(timeout=0.3, started_callback=threadSender.start)
 len(packetsVCan1) == 6
 
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
 =bridge and sniff setup vcan0 package change
 ~ needs_root linux
 
@@ -521,13 +516,14 @@ sock0 = CANSocket(
                                 bitrate=250000, can_filters=[{'can_id': 0x10010000, 'can_mask': 0x1fffffff}]))
 
 def senderVCan1():
-    sleep(0.1)
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
 def bridgeWithPackageChangeVCan1ToVCan0():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -538,25 +534,26 @@ def bridgeWithPackageChangeVCan1ToVCan0():
         pkt.data = b'\x08\x07\x06\x05\x04\x03\x02\x01'
         pkt.identifier = 0x10010000
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithPackageChangeVCan1ToVCan0)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan1)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.3, started_callback=threadSender.start)
 len(packetsVCan0) == 4
-len(packetsVCan1) == 0
 
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
 =bridge and sniff setup vcan0 and vcan1 package change in both directions
 ~ needs_root linux
 
@@ -568,7 +565,6 @@ sock1 = CANSocket(
                                 bitrate=250000, can_filters=[{'can_id': 0x10010000, 'can_mask': 0x1fffffff}]))
 
 def senderBothVCans():
-    sleep(0.2)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -580,7 +576,9 @@ def senderBothVCans():
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
 def bridgeWithPackageChangeBothDirections():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -591,18 +589,18 @@ def bridgeWithPackageChangeBothDirections():
         pkt.data = b'\x08\x07\x06\x05\x04\x03\x02\x01'
         pkt.identifier = 0x10010000
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, xfrm21=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithPackageChangeBothDirections)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderBothVCans)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.3, started_callback=threadSender.start)
 packetsVCan1 = sock1.sniff(timeout=0.3)
 len(packetsVCan0) == 4
 len(packetsVCan1) == 6
@@ -610,6 +608,9 @@ len(packetsVCan1) == 6
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
 =bridge and sniff setup vcan0 package remove
 ~ needs_root linux
 
@@ -621,7 +622,6 @@ sock1 = CANSocket(
                                 bitrate=250000))
 
 def senderVCan0():
-    sleep(0.1)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -629,7 +629,9 @@ def senderVCan0():
     sock0.send(CAN(flags='extended', identifier=0x10040000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
 
+bridgeStarted = threading.Event()
 def bridgeWithRemovePackageFromVCan0ToVCan1():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -642,26 +644,27 @@ def bridgeWithRemovePackageFromVCan0ToVCan1():
         else:
             pkt = pkt
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithRemovePackageFromVCan0ToVCan1)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan0)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+packetsVCan1 = sock1.sniff(timeout=0.3, started_callback=threadSender.start)
 
-len(packetsVCan0) == 0
 len(packetsVCan1) == 5
 
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
 =bridge and sniff setup vcan1 package remove
 ~ needs_root linux
 
@@ -673,13 +676,14 @@ sock1 = CANSocket(
                                 bitrate=250000))
 
 def senderVCan1():
-    sleep(0.1)
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
 def bridgeWithRemovePackageFromVCan1ToVCan0():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -692,26 +696,28 @@ def bridgeWithRemovePackageFromVCan1ToVCan0():
         else:
             pkt = pkt
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm21=pnr, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithRemovePackageFromVCan1ToVCan0)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderVCan1)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
-packetsVCan1 = sock1.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.3, started_callback=threadSender.start)
 
 len(packetsVCan0) == 3
-len(packetsVCan1) == 0
 
 sock0.close()
 sock1.close()
 
+threadBridge.join()
+threadSender.join()
+
+
 =bridge and sniff setup vcan0 and vcan1 package remove both directions
 ~ needs_root linux
 
@@ -723,7 +729,6 @@ sock1 = CANSocket(
                                 bitrate=250000))
 
 def senderBothVCans():
-    sleep(0.2)
     sock0.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10020000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
     sock0.send(CAN(flags='extended', identifier=0x10000000, length=8, data=b'\x01\x02\x03\x04\x05\x06\x07\x08'))
@@ -735,7 +740,9 @@ def senderBothVCans():
     sock1.send(CAN(flags='extended', identifier=0x10050000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
     sock1.send(CAN(flags='extended', identifier=0x10010000, length=8, data=b'\x01\x02\x03\x04\x05\x04\x05\x06'))
 
+bridgeStarted = threading.Event()
 def bridgeWithRemovePackageInBothDirections():
+    global bridgeStarted
     bSock0 = CANSocket(
         iface=can.interface.Bus(bustype='socketcan', channel='vcan0',
                                 bitrate=250000))
@@ -754,18 +761,18 @@ def bridgeWithRemovePackageInBothDirections():
         else:
             pkt = pkt
         return pkt
-    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnrA, xfrm21=pnrB, timeout=0.5)
+    bSock0.timeout = 0.01
+    bSock1.timeout = 0.01
+    bridge_and_sniff(if1=bSock0, if2=bSock1, xfrm12=pnrA, xfrm21=pnrB, timeout=0.5, started_callback=bridgeStarted.set)
     bSock0.close()
     bSock1.close()
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridgeWithRemovePackageInBothDirections)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=senderBothVCans)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = sock0.sniff(timeout=0.3)
+packetsVCan0 = sock0.sniff(timeout=0.3, started_callback=threadSender.start)
 packetsVCan1 = sock1.sniff(timeout=0.3)
 
 len(packetsVCan0) == 3
diff --git a/scapy/contrib/isotp.uts b/scapy/contrib/isotp.uts
index 8696a2c7cd3..53d2502ce59 100644
--- a/scapy/contrib/isotp.uts
+++ b/scapy/contrib/isotp.uts
@@ -108,8 +108,8 @@ else:
 if "python_can" in CANSocket.__module__:
     import can as python_can
     new_can_socket = lambda iface: CANSocket(iface=python_can.interface.Bus(bustype='socketcan', channel=iface, bitrate=250000))
-    new_can_socket0 = lambda: CANSocket(iface=python_can.interface.Bus(bustype='socketcan', channel=iface0, bitrate=250000))
-    new_can_socket1 = lambda: CANSocket(iface=python_can.interface.Bus(bustype='socketcan', channel=iface1, bitrate=250000))
+    new_can_socket0 = lambda: CANSocket(iface=python_can.interface.Bus(bustype='socketcan', channel=iface0, bitrate=250000), timeout=0.01)
+    new_can_socket1 = lambda: CANSocket(iface=python_can.interface.Bus(bustype='socketcan', channel=iface1, bitrate=250000), timeout=0.01)
 else:
     new_can_socket = lambda iface: CANSocket(iface)
     new_can_socket0 = lambda: CANSocket(iface0)
@@ -128,7 +128,7 @@ print("CAN sockets should work now")
 
 # Verify that a CAN socket can be created and closed
 ~ conf linux needs_root
-s = new_can_socket0()
+s = new_can_socket(iface0)
 s.close()
 
 
@@ -643,7 +643,7 @@ def sender(args=None):
     global succ
     succ = True
 
-s = new_can_socket0()
+s = new_can_socket(iface0)
 thread = threading.Thread(target=sender)
 sniffed = ISOTPSniffer.sniff(s, timeout=1, count=1, prn=lambda x: x.show2(), started_callback=thread.start)
 sniffed[0]['ISOTP'].data == bytearray(range(1, 0x29))
@@ -843,8 +843,8 @@ with ISOTPSocket(cans, sid=0x641, did=0x241) as s:
 = Verify that packets are not lost if they arrive before the sniff() is called
 ~ linux needs_root
 
-ss = new_can_socket0()
-sr = new_can_socket0()
+ss = new_can_socket(iface0)
+sr = new_can_socket(iface0)
 print("socket open")
 ss.send(CAN(identifier=0x111, data=b"\x01\x23\x45\x67"))
 time.sleep(0.02)
@@ -860,8 +860,8 @@ del sr
 
 = Send single frame ISOTP message, using begin_send
 ~ linux needs_root
-cans = new_can_socket0()
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+cans = new_can_socket(iface0)
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     s.begin_send(ISOTP(data=dhex("01 02 03 04 05")))
     can = cans.recv()
     assert(can.identifier == 0x641)
@@ -870,8 +870,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 
 = Send many single frame ISOTP messages, using begin_send
 ~ linux needs_root
-cans = new_can_socket0()
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+cans = new_can_socket(iface0)
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     for i in range(100):
         data = dhex("01 02 03 04 05") + struct.pack("B", i)
         expected = struct.pack("B", len(data)) + data
@@ -884,8 +884,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 
 = Send two-frame ISOTP message, using begin_send
 ~ linux needs_root
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
+    cans = new_can_socket(iface0)
     s.begin_send(ISOTP(data=dhex("01 02 03 04 05 06 07 08")))
     can = cans.recv()
     assert can.identifier == 0x641
@@ -899,8 +899,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 = Send single frame ISOTP message
 ~ linux needs_root
 
-cans = new_can_socket0()
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+cans = new_can_socket(iface0)
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     s.send(ISOTP(data=dhex("01 02 03 04 05")))
     can = cans.recv()
     assert(can.identifier == 0x641)
@@ -910,17 +910,17 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 = Send two-frame ISOTP message
 ~ linux needs_root
 
-cans = new_can_socket0()
+cans = new_can_socket(iface0)
 acker_ready = threading.Event()
 def acker():
-    acks = new_can_socket0()
+    acks = new_can_socket(iface0)
     acker_ready.set()
     can = acks.recv()
     acks.send(CAN(identifier = 0x241, data=dhex("30 00 00")))
 
 Thread(target=acker).start()
 acker_ready.wait()
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     s.send(ISOTP(data=dhex("01 02 03 04 05 06 07 08")))
     can = cans.recv()
     assert(can.identifier == 0x641)
@@ -936,8 +936,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 = Receive a single frame ISOTP message
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier = 0x241, data = dhex("05 01 02 03 04 05")))
     isotp = s.recv()
     assert(isotp.data == dhex("01 02 03 04 05"))
@@ -950,8 +950,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 = Receive a single frame ISOTP message, with extended addressing
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, extended_addr=0xc0, extended_rx_addr=0xea) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241, extended_addr=0xc0, extended_rx_addr=0xea) as s:
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier = 0x241, data = dhex("EA 05 01 02 03 04 05")))
     isotp = s.recv()
     assert(isotp.data == dhex("01 02 03 04 05"))
@@ -964,8 +964,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, extended_addr=0xc0, ex
 = Receive a two-frame ISOTP message
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier = 0x241, data = dhex("10 0B 01 02 03 04 05 06")))
     cans.send(CAN(identifier = 0x241, data = dhex("21 07 08 09 10 11")))
     isotp = s.recv()
@@ -975,8 +975,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 = Check what happens when a CAN frame with wrong identifier gets received
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier = 0x141, data = dhex("05 01 02 03 04 05")))
     assert(s.ins.rx_queue.empty())
 
@@ -987,8 +987,8 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
 = Check if not sending the last CF will make the socket timeout
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier = 0x241, data = dhex("10 11 01 02 03 04 05 06")))
     cans.send(CAN(identifier = 0x241, data = dhex("21 07 08 09 0A 0B 0C 0D")))
     isotp = s.sniff(timeout=1)
@@ -1000,8 +1000,8 @@ assert(len(isotp) == 0)
 = Check if not sending the first CF will make the socket timeout
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
-    cans = new_can_socket0()
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier = 0x241, data = dhex("10 11 01 02 03 04 05 06")))
     isotp = s.sniff(timeout=1)
 
@@ -1014,7 +1014,7 @@ assert(len(isotp) == 0)
 exception = None
 isotp = ISOTP(data=dhex("01 02 03 04 05 06 07 08 09 0A"))
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     try:
         s.send(isotp)
         assert(False)
@@ -1034,7 +1034,7 @@ test_sem = threading.Semaphore(0)
 evt = threading.Event()
 
 def acker():
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     evt.set()
     can = cans.recv()
     cans.send(CAN(identifier = 0x241, data=dhex("30 04 00")))
@@ -1043,7 +1043,7 @@ thread = Thread(target=acker)
 thread.start()
 evt.wait()
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     try:
         s.send(isotp)
     except Scapy_Exception as ex:
@@ -1065,7 +1065,7 @@ test_sem = threading.Semaphore(0)
 evt = threading.Event()
 
 def acker():
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     evt.set()
     can = cans.recv()
     cans.send(CAN(identifier = 0x241, data=dhex("32 00 00")))
@@ -1074,7 +1074,7 @@ thread = Thread(target=acker)
 thread.start()
 evt.wait()
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     try:
         s.send(isotp)
     except Scapy_Exception as ex:
@@ -1090,7 +1090,7 @@ assert(str(exception) == "Overflow happened at the receiver side")
 = Close the Socket
 ~ linux needs_root
 
-with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s:
+with ISOTPSocket(new_can_socket(iface0), sid=0x641, did=0x241) as s:
     s.close()
 
 + More complex operations
@@ -1104,14 +1104,14 @@ rx2 = None
 
 def sender():
     global evt, rx2, msg
-    with ISOTPSoftSocket(new_can_socket0(), 0x123, 0x321) as sock:
+    with ISOTPSoftSocket(new_can_socket(iface0), 0x123, 0x321) as sock:
         evt.wait()
         rx2 = sock.sr1(msg, timeout=1, verbose=True)
 
 txThread = threading.Thread(target=sender)
 txThread.start()
 
-with ISOTPSoftSocket(new_can_socket0(), 0x321, 0x123) as sock:
+with ISOTPSoftSocket(new_can_socket(iface0), 0x321, 0x123) as sock:
     evt.set()
     rx = sock.recv()
     sock.send(msg)
@@ -1351,7 +1351,7 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241) as s1, \
 ~ linux needs_root
 
 with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     s.send(ISOTP(data=dhex("01")))
     res = cans.recv()
     assert(res.length == 8)
@@ -1360,10 +1360,10 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
 = Send a two-frame ISOTP message with padding
 ~ linux needs_root
 
-cans = new_can_socket0()
+cans = new_can_socket(iface0)
 acker_ready = threading.Event()
 def acker():
-    acks = new_can_socket0()
+    acks = new_can_socket(iface0)
     acker_ready.set()
     can = acks.recv()
     acks.send(CAN(identifier = 0x241, data=dhex("30 00 00")))
@@ -1388,7 +1388,7 @@ assert(can.data == dhex("21 07 08 00 00 00 00 00"))
 ~ linux needs_root
 
 with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=False) as s:
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier=0x241, data=dhex("02 05 06 00 00 00 00 00")))
     res = s.recv()
     assert(res.data == dhex("05 06"))
@@ -1398,7 +1398,7 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=False) as s:
 ~ linux needs_root
 
 with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier=0x241, data=dhex("02 05 06 00 00 00 00 00")))
     res = s.recv()
     assert(res.data == dhex("05 06"))
@@ -1408,7 +1408,7 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
 ~ linux needs_root
 
 with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier=0x241, data=dhex("02 05 06")))
     res = s.recv()
     assert(res.data == dhex("05 06"))
@@ -1418,7 +1418,7 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
 ~ linux needs_root
 
 with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier=0x241, data=dhex("10 09 01 02 03 04 05 06")))
     cans.send(CAN(identifier=0x241, data=dhex("21 07 08 09 00 00 00 00")))
     res = s.recv()
@@ -1429,7 +1429,7 @@ with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=True) as s:
 ~ linux needs_root
 
 with ISOTPSocket(new_can_socket0(), sid=0x641, did=0x241, padding=False) as s:
-    cans = new_can_socket0()
+    cans = new_can_socket(iface0)
     cans.send(CAN(identifier=0x241, data=dhex("10 09 01 02 03 04 05 06")))
     cans.send(CAN(identifier=0x241, data=dhex("21 07 08 09 00 00 00 00")))
     res = s.recv()
@@ -1594,7 +1594,7 @@ exit_if_no_isotp_module()
 cans = CANSocket(iface0)
 acker_ready = threading.Event()
 def acker():
-    acks = new_can_socket0()
+    acks = new_can_socket(iface0)
     acker_ready.set()
     can = acks.recv()
     acks.send(CAN(identifier = 0x241, data=dhex("30 00 00")))
@@ -1852,10 +1852,12 @@ isoTpSocket1 = ISOTPNativeSocket(iface1, sid=0x641, did=0x241)
 bSocket0 = ISOTPNativeSocket(iface0, sid=0x641, did=0x241)
 bSocket1 = ISOTPNativeSocket(iface1, sid=0x241, did=0x641)
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     def forwarding(pkt):
         return pkt
-    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=2, count=1)
+    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=2, count=1, started_callback=bridgeStarted.set)
     bSocket0.close()
     bSocket1.close()
     global bSucc
@@ -1874,15 +1876,18 @@ rSucc = False
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
 threadSender = threading.Thread(target=RequestOnBus0)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan1 = isoTpSocket1.sniff(timeout=0.5)
+packetsVCan1 = isoTpSocket1.sniff(timeout=0.5, started_callback=threadSender.start)
 
 len(packetsVCan1) == 1
 
 isoTpSocket0.close()
 isoTpSocket1.close()
 
+threadSender.join()
+threadBridge.join()
+
 assert(bSucc)
 assert(rSucc)
 
@@ -1898,12 +1903,14 @@ bSocket1 = ISOTPNativeSocket(iface1, sid=0x241, did=0x641)
 bSucc = False
 rSucc = False
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     global bSucc
     def forwarding(pkt):
         pkt.data = 'changed'
         return pkt
-    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=0.5)
+    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=0.5, started_callback=bridgeStarted.set)
     bSocket0.close()
     bSocket1.close()
     bSucc = True
@@ -1915,14 +1922,11 @@ def RequestOnBus0():
     isoTpSocket0.send(packet)
     rSucc = True
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=RequestOnBus0)
-threadSender.start()
-
-packetsVCan1 = isoTpSocket1.sniff(timeout=0.5)
+bridgeStarted.wait()
+packetsVCan1 = isoTpSocket1.sniff(timeout=0.5, started_callback=threadSender.start)
 
 packetsVCan1[0].data = b'changed'
 len(packetsVCan1) == 1
@@ -1930,6 +1934,9 @@ len(packetsVCan1) == 1
 isoTpSocket0.close()
 isoTpSocket1.close()
 
+threadSender.join()
+threadBridge.join()
+
 assert(bSucc)
 assert(rSucc)
 
@@ -1945,11 +1952,13 @@ isoTpSocket1 = ISOTPNativeSocket(iface1, sid=0x641, did=0x241)
 bSocket0 = ISOTPNativeSocket(iface0, sid=0x641, did=0x241)
 bSocket1 = ISOTPNativeSocket(iface1, sid=0x241, did=0x641)
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     global bSucc
     def forwarding(pkt):
         return pkt
-    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=0.5)
+    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=0.5, started_callback=bridgeStarted.set)
     bSocket0.close()
     bSocket1.close()
     bSucc = True
@@ -1963,14 +1972,12 @@ def RequestBothVCans():
     isoTpSocket1.send(packetVcan1)
     rSucc = True
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=RequestOnBus0)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = isoTpSocket0.sniff(timeout=0.5)
+packetsVCan0 = isoTpSocket0.sniff(timeout=0.5, started_callback=threadSender.start)
 packetsVCan1 = isoTpSocket1.sniff(timeout=0.5)
 
 len(packetsVCan0) == 1
@@ -1979,6 +1986,9 @@ len(packetsVCan1) == 1
 isoTpSocket0.close()
 isoTpSocket1.close()
 
+threadSender.join()
+threadBridge.join()
+
 assert(bSucc)
 assert(rSucc)
 
@@ -1994,12 +2004,14 @@ isoTpSocket1 = ISOTPNativeSocket(iface1, sid=0x641, did=0x241)
 bSocket0 = ISOTPNativeSocket(iface0, sid=0x641, did=0x241)
 bSocket1 = ISOTPNativeSocket(iface1, sid=0x241, did=0x641)
 
+bridgeStarted = threading.Event()
 def bridge():
+    global bridgeStarted
     global bSucc
     def forwarding(pkt):
         pkt.data = 'changed'
         return pkt
-    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=0.5)
+    bridge_and_sniff(if1=bSocket0, if2=bSocket1, xfrm12=forwarding, xfrm21=forwarding, timeout=0.5, started_callback=bridgeStarted.set)
     bSocket0.close()
     bSocket1.close()
     bSucc = True
@@ -2013,14 +2025,12 @@ def RequestBothVCans():
     isoTpSocket1.send(packetVcan1)
     rSucc = True
 
-threadBridge.join()
 threadBridge = threading.Thread(target=bridge)
 threadBridge.start()
-threadSender.join()
 threadSender = threading.Thread(target=RequestBothVCans)
-threadSender.start()
+bridgeStarted.wait()
 
-packetsVCan0 = isoTpSocket0.sniff(timeout=0.5)
+packetsVCan0 = isoTpSocket0.sniff(timeout=0.5, started_callback=threadSender.start)
 packetsVCan1 = isoTpSocket1.sniff(timeout=0.5)
 
 packetsVCan0[0].data = b'changed'
@@ -2031,6 +2041,9 @@ len(packetsVCan1) == 1
 isoTpSocket0.close()
 isoTpSocket1.close()
 
+threadSender.join()
+threadBridge.join()
+
 assert(bSucc)
 assert(rSucc)