hltapi: optimization to utilize similar variables for several fields, fix incorrect size from l3_length, add profiles

17 files changed, 535 insertions, 187 deletions

diff --git a/scripts/automation/regression/hltapi_example.py b/scripts/automation/regression/hltapi_playground.py
index 5695d32f..793b0282 100755
--- a/scripts/automation/regression/hltapi_example.py
+++ b/scripts/automation/regression/hltapi_playground.py
@@ -1,7 +1,8 @@
 #!/router/bin/python
 
 import outer_packages
-from trex_stl_lib.trex_stl_hltapi import CTRexHltApi, CStreamsPerPort
+#from trex_stl_lib.trex_stl_hltapi import CTRexHltApi, CStreamsPerPort
+from trex_stl_lib.trex_stl_hltapi import *
 import traceback
 import sys, time
 from pprint import pprint
@@ -53,13 +54,27 @@ if __name__ == "__main__":
         res = check_res(hlt_client.connect(device = args.device, port_list = [0, 1], username = 'danklei', break_locks = True, reset = True))
         port_handle = res['port_handle']
         print('Connected, got port handles %s' % port_handle)
-        ports_streams_dict = CStreamsPerPort(port_handle)
-
-        print('Imix should create 3 streams (forth ratio is 0)')
-        res = check_res(hlt_client.traffic_config(mode = 'create', l2_encap = 'ethernet_ii_vlan', bidirectional = True, length_mode = 'imix',
-                                                  port_handle = port_handle, save_to_yaml = '/tmp/d1.yaml'))
+        ports_streams_dict = CStreamsPerPort()
+
+        res = check_res(hlt_client.traffic_config(mode = 'create', l2_encap = 'ethernet_ii_vlan', rate_pps = 1,
+                                                  l3_protocol = 'ipv4',
+                                                  length_mode = 'imix', l3_length = 200,
+                                                  ipv6_dst_mode = 'decrement', ipv6_dst_count = 300, ipv6_dst_addr = 'fe80:0:0:0:0:0:0:000f',
+                                                  port_handle = port_handle, port_handle2 = port_handle[1], save_to_yaml = '/tmp/d1.yaml'))
+        #print res
+        #print hlt_client._streams_history
+        #print hlt_client.trex_client._STLClient__get_all_streams(port_id = port_handle[0])
+        #print hlt_client.trex_client._STLClient__get_all_streams(port_id = port_handle[1])
+        #ports_streams_dict.add_streams_from_res(res)
+        sys.exit(0)
+        res = check_res(hlt_client.traffic_config(mode = 'create', l2_encap = 'ethernet_ii_vlan', rate_pps = 1, 
+                                                  port_handle = port_handle[0], port_handle2 = port_handle[1], save_to_yaml = '/tmp/d1.yaml',
+                                                  l4_protocol = 'udp',
+                                                  #udp_src_port_mode = 'decrement',
+                                                  #udp_src_port_count = 10, udp_src_port = 5,
+                                                  ))
         ports_streams_dict.add_streams_from_res(res)
-
+        sys.exit(0)
         #print ports_streams_dict
         #print hlt_client.trex_client._STLClient__get_all_streams(port_id = port_handle[0])
         res = check_res(hlt_client.traffic_config(mode = 'modify', port_handle = port_handle[0], stream_id = ports_streams_dict[0][0],
@@ -71,7 +86,8 @@ if __name__ == "__main__":
         #print hlt_client.trex_client._STLClient__get_all_streams(port_id = port_handle[0])
         check_res(hlt_client.traffic_config(mode = 'reset', port_handle = port_handle))
 
-        res = check_res(hlt_client.traffic_config(mode = 'create', bidirectional = True, length_mode = 'fixed', port_handle = port_handle,
+        res = check_res(hlt_client.traffic_config(mode = 'create', bidirectional = True, length_mode = 'fixed',
+                                                  port_handle = port_handle[0], port_handle2 = port_handle[1],
                                                   transmit_mode = 'single_burst', pkts_per_burst = 100, rate_pps = 100,
                                                   mac_src = '1-2-3-4-5-6',
                                                   mac_dst = '6:5:4:4:5:6',
diff --git a/scripts/automation/regression/unit_tests/functional_tests/hltapi_stream_builder_test.py b/scripts/automation/regression/unit_tests/functional_tests/hltapi_stream_builder_test.py
index df93aba1..297034db 100755
--- a/scripts/automation/regression/unit_tests/functional_tests/hltapi_stream_builder_test.py
+++ b/scripts/automation/regression/unit_tests/functional_tests/hltapi_stream_builder_test.py
@@ -112,30 +112,30 @@ TBD
     self_start: true
     vm:
       instructions:
-      - init_value: 3232235777
-        max_value: 3232235781
-        min_value: 3232235777
-        name: ip_src
+      - init_value: 0
+        max_value: 4
+        min_value: 0
+        name: inc_4_4_1
         op: inc
         size: 4
         step: 1
         type: flow_var
-      - add_value: 0
+      - add_value: 3232235777
         is_big_endian: true
-        name: ip_src
+        name: inc_4_4_1
         pkt_offset: 26
         type: write_flow_var
       - init_value: 0
         max_value: 4294967295
         min_value: 0
-        name: ip_dst
+        name: ip_dst_random
         op: random
         size: 4
         step: 1
         type: flow_var
       - add_value: 0
         is_big_endian: true
-        name: ip_dst
+        name: ip_dst_random
         pkt_offset: 30
         type: write_flow_var
       - pkt_offset: 14
@@ -170,35 +170,35 @@ TBD
     self_start: true
     vm:
       instructions:
-      - init_value: 1024
-        max_value: 1024
-        min_value: 1015
-        name: tcp_src
+      - init_value: 9
+        max_value: 9
+        min_value: 0
+        name: dec_2_9_1
         op: dec
         size: 2
         step: 1
         type: flow_var
-      - add_value: 0
+      - add_value: 1015
         is_big_endian: true
-        name: tcp_src
+        name: dec_2_9_1
         pkt_offset: 34
         type: write_flow_var
       - init_value: 0
         max_value: 65535
         min_value: 0
-        name: tcp_dst
+        name: tcp_dst_random
         op: random
         size: 2
         step: 1
         type: flow_var
       - add_value: 0
         is_big_endian: true
-        name: tcp_dst
+        name: tcp_dst_random
         pkt_offset: 36
         type: write_flow_var
       - pkt_offset: 14
         type: fix_checksum_ipv4
-      split_by_var: tcp_src
+      split_by_var: dec_2_9_1
 '''
 
     # Eth / IP / UDP, udp ports are changed by VM
@@ -247,35 +247,35 @@ TBD
     self_start: true
     vm:
       instructions:
-      - init_value: 1234
-        max_value: 1234
-        min_value: 1225
-        name: udp_src
+      - init_value: 9
+        max_value: 9
+        min_value: 0
+        name: dec_2_9_1
         op: dec
         size: 2
         step: 1
         type: flow_var
-      - add_value: 0
+      - add_value: 1225
         is_big_endian: true
-        name: udp_src
+        name: dec_2_9_1
         pkt_offset: 34
         type: write_flow_var
-      - init_value: 1234
-        max_value: 1243
-        min_value: 1234
-        name: udp_dst
+      - init_value: 0
+        max_value: 9
+        min_value: 0
+        name: inc_2_9_1
         op: inc
         size: 2
         step: 1
         type: flow_var
-      - add_value: 0
+      - add_value: 1234
         is_big_endian: true
-        name: udp_dst
+        name: inc_2_9_1
         pkt_offset: 36
         type: write_flow_var
       - pkt_offset: 14
         type: fix_checksum_ipv4
-      split_by_var: udp_src
+      split_by_var: dec_2_9_1
 '''
 
     # Eth/IP/TCP, packet length is changed in VM by frame_size
@@ -543,7 +543,7 @@ TBD
       pps: 1
       type: continuous
     packet:
-      binary: AAAAAAAAAAABAAABht1gAAAAAFIGQP6AAAAAAAAAAAAAAAAAABL+gAAAAAAAAAAAAAAAAAAiBAAAUAAAAAEAAAABUAAP5Zs3AAAhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhIQ==
+      binary: AAAAAAAAAAABAAABht1gAAAAAG4GQP6AAAAAAAAAAAAAAAAAABL+gAAAAAAAAAAAAAAAAAAiBAAAUAAAAAEAAAABUAAP5ctLAAAhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISE=
       meta: ''
     rx_stats:
       enabled: false
@@ -573,40 +573,40 @@ TBD
       pps: 1
       type: continuous
     packet:
-      binary: AAAAAAAAAAABAAABht1gAAAAAFIRQBERIiIzM0REVVVmZnd3iIgRERERERERERERERERERERBAAAUABSQkIhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhIQ==
+      binary: AAAAAAAAAAABAAABht1gAAAAAG4RQBERIiIzM0REVVVmZnd3iIgRERERERERERERERERERERBAAAUABucjohISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhISE=
       meta: ''
     rx_stats:
       enabled: false
     self_start: true
     vm:
       instructions:
-      - init_value: 2004322440
-        max_value: 2004322485
-        min_value: 2004322440
-        name: ipv6_src
+      - init_value: 0
+        max_value: 45
+        min_value: 0
+        name: inc_4_9_5
         op: inc
         size: 4
         step: 5
         type: flow_var
-      - add_value: 0
+      - add_value: 2004322440
         is_big_endian: true
-        name: ipv6_src
+        name: inc_4_9_5
         pkt_offset: 34
         type: write_flow_var
-      - init_value: 286331153
-        max_value: 286331153
-        min_value: 286328620
-        name: ipv6_dst
+      - init_value: 2533
+        max_value: 2533
+        min_value: 0
+        name: dec_4_149_17
         op: dec
         size: 4
         step: 17
         type: flow_var
-      - add_value: 0
+      - add_value: 286328620
         is_big_endian: true
-        name: ipv6_dst
+        name: dec_4_149_17
         pkt_offset: 50
         type: write_flow_var
-      split_by_var: ipv6_dst
+      split_by_var: dec_4_149_17
 '''
 
 
diff --git a/scripts/automation/regression/unit_tests/functional_tests/stl_basic_tests.py b/scripts/automation/regression/unit_tests/functional_tests/stl_basic_tests.py
index e6a82cf1..0d1c9761 100644
--- a/scripts/automation/regression/unit_tests/functional_tests/stl_basic_tests.py
+++ b/scripts/automation/regression/unit_tests/functional_tests/stl_basic_tests.py
@@ -197,9 +197,14 @@ class CStlBasic_Test(functional_general_test.CGeneralFunctional_Test):
     def test_hlt_profiles (self):
         p = (
             ['hlt/hlt_udp_inc_dec_len_9k.py', '-m 1 -l 20', True],
-            ['hlt/hlt_imix_default.py', '-m 1 -l 40', True],
+            ['hlt/hlt_imix_default.py', '-m 1 -l 20', True],
+            ['hlt/hlt_imix_4rates.py', '-m 1 -l 20', True],
+            ['hlt/hlt_david1.py', '-m 1 -l 20', True],
+            ['hlt/hlt_david2.py', '-m 1 -l 20', True],
+            ['hlt/hlt_david3.py', '-m 1 -l 20', True],
+            ['hlt/hlt_david4.py', '-m 1 -l 20', True],
+            ['hlt/hlt_tcp_ranges.py', '-m 1 -l 20', True],
             )
-        
 
         for obj in p:
             self.run_py_profile_path (obj[0], obj[1], compare =obj[2], do_no_remove=True)
diff --git a/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_hltapi.py b/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_hltapi.py
index 60654f0a..581ea418 100755
--- a/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_hltapi.py
+++ b/scripts/automation/trex_control_plane/stl/trex_stl_lib/trex_stl_hltapi.py
@@ -212,7 +212,7 @@ def correct_macs(kwargs):
     list_of_mac_steps = ['mac_src_step', 'mac_dst_step', 'mac_src2_step', 'mac_dst2_step']
     for mac_arg in list_of_mac_args + list_of_mac_steps:
         if mac_arg in kwargs:
-            if type(kwargs[mac_arg]) in (int, long) and kwargs[mac_arg] in list_of_mac_steps: # step can be number
+            if type(kwargs[mac_arg]) in (int, long) and mac_arg in list_of_mac_steps: # step can be number
                 continue
             if type(kwargs[mac_arg]) is not str: raise STLError('Argument %s should be str' % mac_arg)
             kwargs[mac_arg] = kwargs[mac_arg].replace('{', '').replace('}', '').strip().replace('-', ' ').replace(':', ' ').replace('.', ' ')
@@ -483,7 +483,7 @@ class CTRexHltApi(object):
         if mode == 'create' or mode == 'modify':
             # create a new stream with desired attributes, starting by creating packet
             streams_per_port = CStreamsPerPort()
-            if kwargs['bidirectional']: # two streams with opposite directions
+            if is_true(kwargs['bidirectional']): # two streams with opposite directions
                 del user_kwargs['bidirectional']
                 save_to_yaml = user_kwargs.get('save_to_yaml')
                 bidirect_err = 'When using bidirectional flag, '
@@ -502,8 +502,6 @@ class CTRexHltApi(object):
                     streams_per_port.add_streams_from_res(res1)
                     kwargs['direction'] = 1 - kwargs['direction'] # not
                     correct_direction(user_kwargs, kwargs)
-                    user_kwargs['mac_src'] = kwargs['mac_src2']
-                    user_kwargs['mac_dst'] = kwargs['mac_dst2']
                     if save_to_yaml and type(save_to_yaml) is str:
                         user_kwargs['save_to_yaml'] = save_to_yaml.replace('.yaml', '_bi2.yaml')
                     user_kwargs['port_handle'] = port_handle2
@@ -713,7 +711,7 @@ def STLHltStream(**user_kwargs):
             transmit_mode_class = STLTXSingleBurst(pps = rate_pps, total_pkts = pkts_per_burst)
         elif transmit_mode == 'multi_burst':
             transmit_mode_class = STLTXMultiBurst(pps = rate_pps, total_pkts = pkts_per_burst,
-                                                  count = kwargs['burst_loop_count'], ibg = kwargs['inter_burst_gap'])
+                                                  count = int(kwargs['burst_loop_count']), ibg = kwargs['inter_burst_gap'])
         else:
             raise STLError('transmit_mode %s not supported/implemented')
     except Exception as e:
@@ -744,6 +742,7 @@ def generate_packet(**user_kwargs):
     correct_direction(kwargs, kwargs)
 
     vm_cmds = []
+    vm_variables_cache = {} # we will keep in cache same variables (inc/dec, var size in bytes, number of steps, step)
     fix_ipv4_checksum = False
 
     ### L2 ###
@@ -754,27 +753,39 @@ def generate_packet(**user_kwargs):
         l2_layer = Ether(src = kwargs['mac_src'], dst = kwargs['mac_dst'])
 
         # Eth VM
-        # WIP!!! Need 8 bytes mask and vars
+        # !!!! Need 8 bytes mask and vars !!!! for now will change only 32 lsb
         if kwargs['mac_src_mode'] != 'fixed':
-            mac_src_count = kwargs['mac_src_count'] - 1
-            if mac_src_count < 0:
+            count = int(kwargs['mac_src_count']) - 1
+            if count < 0:
                 raise STLError('mac_src_count has to be at least 1')
-            if mac_src_count > 0:
+            if count > 0:
                 mac_src = mac_str_to_num(mac2str(kwargs['mac_src']))
+                step = kwargs['mac_src_step']
+                if step < 1:
+                    raise STLError('mac_src_step has to be at least 1')
+                if type(step) is str:
+                    step = mac_str_to_num(mac2str(step))
+                add_val = 0
                 if kwargs['mac_src_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'mac_src', size = 4, op = 'inc', step = kwargs['mac_src_step'],
-                                                      min_value = mac_src,
-                                                      max_value = mac_src + mac_src_count * kwargs['mac_src_step']))
+                    add_val = mac_src
+                    var_name = '%s_%s_%s_%s' % ('inc', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['mac_src_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'mac_src', size = 4, op = 'dec', step = kwargs['mac_src_step'],
-                                                       min_value = mac_src - mac_src_count * kwargs['mac_src_step'],
-                                                       max_value = mac_src))
+                    add_val = mac_src - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = 'mac_src', size = 4, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['mac_src_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'mac_src', size = 4, op = 'random', min_value = 0, max_value = 0xffffffffffffffff))
+                    var_name = 'mac_src_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'random', max_value = 0xffffffffffff))
                 else:
                     raise STLError('mac_src_mode %s is not supported' % kwargs['mac_src_mode'])
-                vm_cmds.append(STLVmWrMaskFlowVar(fv_name = 'mac_src', pkt_offset = 'Ethernet.src', pkt_cast_size = 4, mask = 0xffffffff))
-
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'Ethernet.src', offset_fixup = 2, add_val = add_val))
         
         if kwargs['l2_encap'] == 'ethernet_ii_vlan' or (kwargs['l2_encap'] == 'ethernet_ii' and vlan_in_args(user_kwargs)):
                 #fields_desc =  [ BitField("prio", 0, 3),
@@ -783,9 +794,9 @@ def generate_packet(**user_kwargs):
                 #                 XShortEnumField("type", 0x0000, ETHER_TYPES) ]
             for i, vlan_kwargs in enumerate(split_vlan_args(kwargs)):
                 vlan_id = int(vlan_kwargs['vlan_id'])
-                dot1q_kwargs = {'prio': vlan_kwargs['vlan_user_priority'],
+                dot1q_kwargs = {'prio': int(vlan_kwargs['vlan_user_priority']),
                                 'vlan': vlan_id,
-                                'id':   vlan_kwargs['vlan_cfi']}
+                                'id':   int(vlan_kwargs['vlan_cfi'])}
                 vlan_protocol_tag_id = vlan_kwargs['vlan_protocol_tag_id']
                 if vlan_protocol_tag_id is not None:
                     if type(vlan_protocol_tag_id) is str:
@@ -796,19 +807,21 @@ def generate_packet(**user_kwargs):
                 # vlan VM
                 vlan_id_mode = vlan_kwargs['vlan_id_mode']
                 if vlan_id_mode != 'fixed':
-                    vlan_id_count = int(vlan_kwargs['vlan_id_count']) - 1
-                    if vlan_id_count < 0:
+                    count = int(vlan_kwargs['vlan_id_count']) - 1
+                    if count < 0:
                         raise STLError('vlan_id_count has to be at least 1')
-                    if vlan_id_count > 0 or vlan_id_mode == 'random':
+                    if count > 0 or vlan_id_mode == 'random':
                         var_name = 'vlan_id%s' % i
                         step = int(vlan_kwargs['vlan_id_step'])
+                        if step < 1:
+                            raise STLError('vlan_id_step has to be at least 1')
                         if vlan_id_mode == 'increment':
                             vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'inc', step = step,
                                                               min_value = vlan_id,
-                                                              max_value = vlan_id + vlan_id_count * step))
+                                                              max_value = vlan_id + count * step))
                         elif vlan_id_mode == 'decrement':
                             vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'dec', step = step,
-                                                               min_value = vlan_id - vlan_id_count * step,
+                                                               min_value = vlan_id - count * step,
                                                                max_value = vlan_id))
                         elif vlan_id_mode == 'random':
                             vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'random', min_value = 0, max_value = 0xffff))
@@ -850,56 +863,77 @@ def generate_packet(**user_kwargs):
                       )
         # IPv4 VM
         if kwargs['ip_src_mode'] != 'fixed':
-            ip_src_count = kwargs['ip_src_count'] - 1
-            if ip_src_count < 0:
+            count = int(kwargs['ip_src_count']) - 1
+            if count < 0:
                 raise STLError('ip_src_count has to be at least 1')
-            if ip_src_count > 0:
+            if count > 0:
                 fix_ipv4_checksum = True
+                add_val = 0
                 ip_src_addr = kwargs['ip_src_addr']
                 if type(ip_src_addr) is str:
                     ip_src_addr = ipv4_str_to_num(is_valid_ipv4(ip_src_addr))
-                ip_src_step = kwargs['ip_src_step']
-                if type(ip_src_step) is str:
-                    ip_src_step = ipv4_str_to_num(is_valid_ipv4(ip_src_step))
+                step = kwargs['ip_src_step']
+                if step < 1:
+                    raise STLError('ip_src_step has to be at least 1')
+                if type(step) is str:
+                    step = ipv4_str_to_num(is_valid_ipv4(step))
                 if kwargs['ip_src_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ip_src', size = 4, op = 'inc', step = ip_src_step,
-                                                      min_value = ip_src_addr,
-                                                      max_value = ip_src_addr + ip_src_count * ip_src_step))
+                    add_val = ip_src_addr
+                    var_name = '%s_%s_%s_%s' % ('inc', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ip_src_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ip_src', size = 4, op = 'dec', step = ip_src_step,
-                                                       min_value = ip_src_addr - ip_src_count * ip_src_step,
-                                                       max_value = ip_src_addr))
+                    add_val = ip_src_addr - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ip_src_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ip_src', size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
+                    var_name = 'ip_src_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
                 else:
                     raise STLError('ip_src_mode %s is not supported' % kwargs['ip_src_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='ip_src', pkt_offset = 'IP.src'))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'IP.src', add_val = add_val))
 
         if kwargs['ip_dst_mode'] != 'fixed':
-            ip_dst_count = kwargs['ip_dst_count'] - 1
-            if ip_dst_count < 0:
+            count = int(kwargs['ip_dst_count']) - 1
+            if count < 0:
                 raise STLError('ip_dst_count has to be at least 1')
-            if ip_dst_count > 0:
+            if count > 0:
                 fix_ipv4_checksum = True
+                add_val = 0
                 ip_dst_addr = kwargs['ip_dst_addr']
                 if type(ip_dst_addr) is str:
                     ip_dst_addr = ipv4_str_to_num(is_valid_ipv4(ip_dst_addr))
-                ip_dst_step = kwargs['ip_dst_step']
-                if type(ip_dst_step) is str:
-                    ip_dst_step = ipv4_str_to_num(is_valid_ipv4(ip_dst_step))
+                step = kwargs['ip_dst_step']
+                if step < 1:
+                    raise STLError('ip_dst_step has to be at least 1')
+                if type(step) is str:
+                    step = ipv4_str_to_num(is_valid_ipv4(step))
                 if kwargs['ip_dst_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ip_dst', size = 4, op = 'inc', step = ip_dst_step,
-                                                       min_value = ip_dst_addr,
-                                                       max_value = ip_dst_addr + ip_dst_count * ip_dst_step))
+                    add_val = ip_dst_addr
+                    var_name = '%s_%s_%s_%s' % ('inc', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ip_dst_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ip_dst', size = 4, op = 'dec', step = ip_dst_step,
-                                                       min_value = ip_dst_addr - ip_dst_count * ip_dst_step,
-                                                       max_value = ip_dst_addr))
+                    add_val = ip_dst_addr - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ip_dst_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ip_dst', size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
+                    var_name = 'ip_dst_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
                 else:
                     raise STLError('ip_dst_mode %s is not supported' % kwargs['ip_dst_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='ip_dst', pkt_offset = 'IP.dst'))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'IP.dst', add_val = add_val))
+
     elif kwargs['l3_protocol'] == 'ipv6':
                 #fields_desc = [ BitField("version" , 6 , 4),
                 #                BitField("tc", 0, 8), #TODO: IPv6, ByteField ?
@@ -922,50 +956,70 @@ def generate_packet(**user_kwargs):
 
         # IPv6 VM
         if kwargs['ipv6_src_mode'] != 'fixed':
-            ipv6_src_count = kwargs['ipv6_src_count'] - 1
-            if ipv6_src_count < 0:
+            count = int(kwargs['ipv6_src_count']) - 1
+            if count < 0:
                 raise STLError('ipv6_src_count has to be at least 1')
-            if ipv6_src_count > 0:
+            if count > 0:
+                add_val = 0
                 ipv6_src_addr_num = ipv4_str_to_num(is_valid_ipv6(kwargs['ipv6_src_addr'])[-4:])
-                ipv6_src_step = kwargs['ipv6_src_step']
-                if type(ipv6_src_step) is str: # convert ipv6 step to number
-                    ipv6_src_step = ipv4_str_to_num(is_valid_ipv6(ipv6_src_step)[-4:])
+                step = kwargs['ipv6_src_step']
+                if step < 1:
+                    raise STLError('ipv6_src_step has to be at least 1')
+                if type(step) is str: # convert ipv6 step to number
+                    step = ipv4_str_to_num(is_valid_ipv6(step)[-4:])
                 if kwargs['ipv6_src_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ipv6_src', size = 4, op = 'inc', step = ipv6_src_step,
-                                                      min_value = ipv6_src_addr_num,
-                                                      max_value = ipv6_src_addr_num + ipv6_src_count * ipv6_src_step))
+                    add_val = ipv6_src_addr_num
+                    var_name = '%s_%s_%s_%s' % ('inc', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ipv6_src_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ipv6_src', size = 4, op = 'dec', step = ipv6_src_step,
-                                                       min_value = ipv6_src_addr_num - ipv6_src_count * ipv6_src_step,
-                                                       max_value = ipv6_src_addr_num))
+                    add_val = ipv6_src_addr_num - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ipv6_src_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ipv6_src', size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
+                    var_name = 'ipv6_src_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
                 else:
                     raise STLError('ipv6_src_mode %s is not supported' % kwargs['ipv6_src_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='ipv6_src', pkt_offset = 'IPv6.src', offset_fixup = 12))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'IPv6.src', offset_fixup = 12, add_val = add_val))
 
         if kwargs['ipv6_dst_mode'] != 'fixed':
-            ipv6_dst_count = kwargs['ipv6_dst_count'] - 1
-            if ipv6_dst_count < 0:
+            count = int(kwargs['ipv6_dst_count']) - 1
+            if count < 0:
                 raise STLError('ipv6_dst_count has to be at least 1')
-            if ipv6_dst_count > 0:
+            if count > 0:
+                add_val = 0
                 ipv6_dst_addr_num = ipv4_str_to_num(is_valid_ipv6(kwargs['ipv6_dst_addr'])[-4:])
-                ipv6_dst_step = kwargs['ipv6_dst_step']
-                if type(ipv6_dst_step) is str: # convert ipv6 step to number
-                    ipv6_dst_step = ipv4_str_to_num(is_valid_ipv6(ipv6_dst_step)[-4:])
+                step = kwargs['ipv6_dst_step']
+                if step < 1:
+                    raise STLError('ipv6_dst_step has to be at least 1')
+                if type(step) is str: # convert ipv6 step to number
+                    step = ipv4_str_to_num(is_valid_ipv6(step)[-4:])
                 if kwargs['ipv6_dst_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ipv6_dst', size = 4, op = 'inc', step = ipv6_dst_step,
-                                                      min_value = ipv6_dst_addr_num,
-                                                      max_value = ipv6_dst_addr_num + ipv6_dst_count * ipv6_dst_step))
+                    add_val = ipv6_dst_addr_num
+                    var_name = '%s_%s_%s_%s' % ('inc', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ipv6_dst_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ipv6_dst', size = 4, op = 'dec', step = ipv6_dst_step,
-                                                       min_value = ipv6_dst_addr_num - ipv6_dst_count * ipv6_dst_step,
-                                                       max_value = ipv6_dst_addr_num))
+                    add_val = ipv6_dst_addr_num - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 4, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['ipv6_dst_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'ipv6_dst', size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
+                    var_name = 'ipv6_dst_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 4, op = 'random', min_value = 0, max_value = 0xffffffff))
                 else:
                     raise STLError('ipv6_dst_mode %s is not supported' % kwargs['ipv6_dst_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='ipv6_dst', pkt_offset = 'IPv6.dst', offset_fixup = 12))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'IPv6.dst', offset_fixup = 12, add_val = add_val))
 
     else:
         raise NotImplementedError("l3_protocol '%s' is not supported by TRex yet." % kwargs['l3_protocol'])
@@ -1003,44 +1057,66 @@ def generate_packet(**user_kwargs):
                        )
         # TCP VM
         if kwargs['tcp_src_port_mode'] != 'fixed':
-            tcp_src_port_count = kwargs['tcp_src_port_count'] - 1
-            if tcp_src_port_count < 0:
+            count = int(kwargs['tcp_src_port_count']) - 1
+            if count < 0:
                 raise STLError('tcp_src_port_count has to be at least 1')
-            if tcp_src_port_count > 0:
+            if count > 0:
                 fix_ipv4_checksum = True
+                add_val = 0
+                step = kwargs['tcp_src_port_step']
+                if step < 1:
+                    raise STLError('tcp_src_port_step has to be at least 1')
                 if kwargs['tcp_src_port_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'tcp_src', size = 2, op = 'inc', step = kwargs['tcp_src_port_step'],
-                                                      min_value = kwargs['tcp_src_port'],
-                                                      max_value = kwargs['tcp_src_port'] + tcp_src_port_count * kwargs['tcp_src_port_step']))
+                    add_val = kwargs['tcp_src_port']
+                    var_name = '%s_%s_%s_%s' % ('inc', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['tcp_src_port_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'tcp_src', size = 2, op = 'dec', step = kwargs['tcp_src_port_step'],
-                                                      min_value = kwargs['tcp_src_port'] - tcp_src_port_count * kwargs['tcp_src_port_step'],
-                                                      max_value = kwargs['tcp_src_port']))
+                    add_val = kwargs['tcp_src_port'] - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['tcp_src_port_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'tcp_src', size = 2, op = 'random', min_value = 0, max_value = 0xffff))
+                    var_name = 'tcp_src_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'random', min_value = 0, max_value = 0xffff))
                 else:
                     raise STLError('tcp_src_port_mode %s is not supported' % kwargs['tcp_src_port_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='tcp_src', pkt_offset = 'TCP.sport'))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'TCP.sport', add_val = add_val))
 
         if kwargs['tcp_dst_port_mode'] != 'fixed':
-            tcp_dst_port_count = kwargs['tcp_dst_port_count'] - 1
-            if tcp_dst_port_count < 0:
+            count = int(kwargs['tcp_dst_port_count']) - 1
+            if count < 0:
                 raise STLError('tcp_dst_port_count has to be at least 1')
-            if tcp_dst_port_count > 0:
+            if count > 0:
                 fix_ipv4_checksum = True
+                add_val = 0
+                step = kwargs['tcp_dst_port_step']
+                if step < 1:
+                    raise STLError('tcp_dst_port_step has to be at least 1')
                 if kwargs['tcp_dst_port_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'tcp_dst', size = 2, op = 'inc', step = kwargs['tcp_dst_port_step'],
-                                                      min_value = kwargs['tcp_dst_port'],
-                                                      max_value = kwargs['tcp_dst_port'] + tcp_dst_port_count * kwargs['tcp_dst_port_step']))
+                    add_val = kwargs['tcp_dst_port']
+                    var_name = '%s_%s_%s_%s' % ('inc', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['tcp_dst_port_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'tcp_dst', size = 2, op = 'dec', step = kwargs['tcp_dst_port_step'],
-                                                      min_value = kwargs['tcp_dst_port'] - tcp_dst_port_count * kwargs['tcp_dst_port_step'],
-                                                      max_value = kwargs['tcp_dst_port']))
+                    add_val = kwargs['tcp_dst_port'] - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['tcp_dst_port_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'tcp_dst', size = 2, op = 'random', min_value = 0, max_value = 0xffff))
+                    var_name = 'tcp_dst_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'random', min_value = 0, max_value = 0xffff))
                 else:
                     raise STLError('tcp_dst_port_mode %s is not supported' % kwargs['tcp_dst_port_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='tcp_dst', pkt_offset = 'TCP.dport'))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'TCP.dport', add_val = add_val))
 
     elif kwargs['l4_protocol'] == 'udp':
                 #fields_desc = [ ShortEnumField("sport", 53, UDP_SERVICES),
@@ -1052,44 +1128,64 @@ def generate_packet(**user_kwargs):
                        len    = kwargs['udp_length'], chksum = None)
         # UDP VM
         if kwargs['udp_src_port_mode'] != 'fixed':
-            udp_src_port_count = kwargs['udp_src_port_count'] - 1
-            if udp_src_port_count < 0:
+            count = int(kwargs['udp_src_port_count']) - 1
+            if count < 0:
                 raise STLError('udp_src_port_count has to be at least 1')
-            if udp_src_port_count > 0:
+            if count > 0:
                 fix_ipv4_checksum = True
+                add_val = 0
+                step = kwargs['udp_src_port_step']
+                if step < 1:
+                    raise STLError('udp_src_port_step has to be at least 1')
                 if kwargs['udp_src_port_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'udp_src', size = 2, op = 'inc', step = kwargs['udp_src_port_step'],
-                                                      min_value = kwargs['udp_src_port'],
-                                                      max_value = kwargs['udp_src_port'] + udp_src_port_count * kwargs['udp_src_port_step']))
+                    add_val = kwargs['udp_src_port']
+                    var_name = '%s_%s_%s_%s' % ('inc', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'inc', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['udp_src_port_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'udp_src', size = 2, op = 'dec', step = kwargs['udp_src_port_step'],
-                                                      min_value = kwargs['udp_src_port'] - udp_src_port_count * kwargs['udp_src_port_step'],
-                                                      max_value = kwargs['udp_src_port']))
+                    add_val = kwargs['udp_src_port'] - count * step
+                    var_name = '%s_%s_%s_%s' % ('dec', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'dec', step = step,
+                                                          max_value = count * step))
+                        vm_variables_cache[var_name] = True
                 elif kwargs['udp_src_port_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'udp_src', size = 2, op = 'random', min_value = 0, max_value = 0xffff))
+                    var_name = 'udp_src_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'random', min_value = 0, max_value = 0xffff))
                 else:
                     raise STLError('udp_src_port_mode %s is not supported' % kwargs['udp_src_port_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='udp_src', pkt_offset = 'UDP.sport'))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'UDP.sport', add_val = add_val))
 
         if kwargs['udp_dst_port_mode'] != 'fixed':
-            udp_dst_port_count = kwargs['udp_dst_port_count'] - 1
-            if udp_dst_port_count < 0:
+            count = int(kwargs['udp_dst_port_count']) - 1
+            if count < 0:
                 raise STLError('udp_dst_port_count has to be at least 1')
-            if udp_dst_port_count > 0:
+            if count > 0:
                 fix_ipv4_checksum = True
+                add_val = 0
+                step = kwargs['udp_dst_port_step']
+                if step < 1:
+                    raise STLError('udp_dst_port_step has to be at least 1')
                 if kwargs['udp_dst_port_mode'] == 'increment':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'udp_dst', size = 2, op = 'inc', step = kwargs['udp_dst_port_step'],
-                                                      min_value = kwargs['udp_dst_port'],
-                                                      max_value = kwargs['udp_dst_port'] + udp_dst_port_count * kwargs['udp_dst_port_step']))
+                    add_val = kwargs['udp_dst_port']
+                    var_name = '%s_%s_%s_%s' % ('inc', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'inc', step = step,
+                                                          max_value = count * step))
                 elif kwargs['udp_dst_port_mode'] == 'decrement':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'udp_dst', size = 2, op = 'dec', step = kwargs['udp_dst_port_step'],
-                                                      min_value = kwargs['udp_dst_port'] - udp_dst_port_count * kwargs['udp_dst_port_step'],
-                                                      max_value = kwargs['udp_dst_port']))
+                    add_val = kwargs['udp_dst_port']
+                    var_name = '%s_%s_%s_%s' % ('dec', 2, count, step)
+                    if var_name not in vm_variables_cache:
+                        vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'dec', step = step,
+                                                          max_value = count * step))
                 elif kwargs['udp_dst_port_mode'] == 'random':
-                    vm_cmds.append(CTRexVmDescFlowVar(name = 'udp_dst', size = 2, op = 'random', min_value = 0, max_value = 0xffff))
+                    var_name = 'udp_dst_random'
+                    vm_cmds.append(CTRexVmDescFlowVar(name = var_name, size = 2, op = 'random', min_value = 0, max_value = 0xffff))
                 else:
                     raise STLError('udp_dst_port_mode %s is not supported' % kwargs['udp_dst_port_mode'])
-                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name='udp_dst', pkt_offset = 'UDP.dport'))
+                vm_cmds.append(CTRexVmDescWrFlowVar(fv_name = var_name, pkt_offset = 'UDP.dport', add_val = add_val))
     else:
         raise NotImplementedError("l4_protocol '%s' is not supported by TRex yet." % kwargs['l3_protocol'])
     base_pkt /= l4_layer
@@ -1099,10 +1195,10 @@ def generate_packet(**user_kwargs):
     if length_mode == 'auto':
         payload_len = 0
     elif length_mode == 'fixed':
-        if 'frame_size' in user_kwargs:
+        if 'frame_size' in user_kwargs: # L2 has higher priority over L3
             payload_len = kwargs['frame_size'] - len(base_pkt)
         elif 'l3_length' in user_kwargs:
-            payload_len = kwargs['l3_length'] - len(base_pkt) - len(l2_layer)
+            payload_len = kwargs['l3_length'] - (len(base_pkt) - len(l2_layer))
         else: # default
             payload_len = kwargs['frame_size'] - len(base_pkt)
     elif length_mode == 'imix':
@@ -1151,9 +1247,7 @@ def generate_packet(**user_kwargs):
         vm_cmds.append(CTRexVmDescFixIpv4(offset = 'IP'))
     if vm_cmds:
         split_by_field = None
-        if kwargs['split_by_cores'] == 'single':
-            raise STLError("split_by_cores 'single' not implemented yet")
-        elif kwargs['split_by_cores'] == 'split':
+        if kwargs['split_by_cores'] == 'split':
             max_length = 0
             for cmd in vm_cmds:
                 if isinstance(cmd, CTRexVmDescFlowVar):
@@ -1166,8 +1260,10 @@ def generate_packet(**user_kwargs):
                     if length > max_length:
                         max_length = length
                         split_by_field = cmd.name
+        elif kwargs['split_by_cores'] == 'single':
+            raise STLError("split_by_cores 'single' not implemented yet")
         elif kwargs['split_by_cores'] != 'duplicate':
-            raise STLError("split_by_cores '%s' not supported" % kwargs['split_by_cores'])
+            raise STLError("split_by_cores '%s' is not supported" % kwargs['split_by_cores'])
         pkt.add_command(CTRexScRaw(vm_cmds, split_by_field))
 
     # debug (only the base packet, without VM)
@@ -1226,7 +1322,8 @@ def split_vlan_args(kwargs):
 def correct_direction(user_kwargs, kwargs):
     if kwargs['direction'] == 0:
         return
-    user_kwargs['mac_src'], user_kwargs['mac_dst'] = kwargs['mac_dst'], kwargs['mac_src']
+    user_kwargs['mac_src'] = kwargs['mac_src2']
+    user_kwargs['mac_dst'] = kwargs['mac_dst2']
     if kwargs['l3_protocol'] == 'ipv4':
         for arg in kwargs.keys():
             if 'ip_src_' in arg:
diff --git a/scripts/exp/hlt_david1.pcap b/scripts/exp/hlt_david1.pcap
new file mode 100644
index 00000000..54013ae8
--- /dev/null
+++ b/scripts/exp/hlt_david1.pcap
diff --git a/scripts/exp/hlt_david2.pcap b/scripts/exp/hlt_david2.pcap
new file mode 100644
index 00000000..8a75dd01
--- /dev/null
+++ b/scripts/exp/hlt_david2.pcap
diff --git a/scripts/exp/hlt_david3.pcap b/scripts/exp/hlt_david3.pcap
new file mode 100644
index 00000000..2044d2f3
--- /dev/null
+++ b/scripts/exp/hlt_david3.pcap
diff --git a/scripts/exp/hlt_david4.pcap b/scripts/exp/hlt_david4.pcap
new file mode 100644
index 00000000..46995494
--- /dev/null
+++ b/scripts/exp/hlt_david4.pcap
diff --git a/scripts/exp/hlt_imix_4rates.pcap b/scripts/exp/hlt_imix_4rates.pcap
new file mode 100644
index 00000000..e5b355ae
--- /dev/null
+++ b/scripts/exp/hlt_imix_4rates.pcap
diff --git a/scripts/exp/hlt_imix_default.pcap b/scripts/exp/hlt_imix_default.pcap
index eb124acb..aaba789c 100644
--- a/scripts/exp/hlt_imix_default.pcap
+++ b/scripts/exp/hlt_imix_default.pcap
diff --git a/scripts/exp/hlt_tcp_ranges.pcap b/scripts/exp/hlt_tcp_ranges.pcap
new file mode 100644
index 00000000..0dd0d83a
--- /dev/null
+++ b/scripts/exp/hlt_tcp_ranges.pcap
diff --git a/scripts/stl/hlt/hlt_david1.py b/scripts/stl/hlt/hlt_david1.py
new file mode 100755
index 00000000..879ea527
--- /dev/null
+++ b/scripts/stl/hlt/hlt_david1.py
@@ -0,0 +1,43 @@
+from trex_stl_lib.trex_stl_hltapi import STLHltStream
+
+
+class STLS1(object):
+
+    def create_streams (self, direction = 0):
+        return STLHltStream(
+                #enable_auto_detect_instrumentation = '1', # not supported yet
+                ip_dst_addr = '192.168.1.3',
+                ip_dst_count = '1',
+                ip_dst_mode = 'increment',
+                ip_dst_step = '0.0.0.1',
+                ip_src_addr = '192.168.0.3',
+                ip_src_count = '1',
+                ip_src_mode = 'increment',
+                ip_src_step = '0.0.0.1',
+                l3_imix1_ratio = 7,
+                l3_imix1_size = 70,
+                l3_imix2_ratio = 4,
+                l3_imix2_size = 570,
+                l3_imix3_ratio = 1,
+                l3_imix3_size = 1518,
+                l3_protocol = 'ipv4',
+                length_mode = 'imix',
+                #mac_dst_mode = 'discovery', # not supported yet
+                mac_src = '00.00.c0.a8.00.03',
+                mac_src2 = '00.00.c0.a8.01.03',
+                pkts_per_burst = '200000',
+                #rate_percent = '0.4', # not supported yet
+                transmit_mode = 'continuous',
+                vlan_id = '1',
+                direction = direction,
+                )
+
+    def get_streams (self, direction = 0):
+        return self.create_streams(direction)
+
+# dynamic load - used for trex console or simulator
+def register():
+    return STLS1()
+
+
+
diff --git a/scripts/stl/hlt/hlt_david2.py b/scripts/stl/hlt/hlt_david2.py
new file mode 100755
index 00000000..be21c93d
--- /dev/null
+++ b/scripts/stl/hlt/hlt_david2.py
@@ -0,0 +1,42 @@
+from trex_stl_lib.trex_stl_hltapi import STLHltStream
+
+
+class STLS1(object):
+
+    def create_streams (self, direction = 0):
+        return STLHltStream(
+                #enable_auto_detect_instrumentation = '1', # not supported yet
+                ip_dst_addr = '192.168.3.3',
+                ip_dst_count = '1',
+                ip_dst_mode = 'increment',
+                ip_dst_step = '0.0.0.1',
+                ip_src_addr = '192.168.2.3',
+                ip_src_count = '1',
+                ip_src_step = '0.0.0.1',
+                l3_imix1_ratio = 7,
+                l3_imix1_size = 68,
+                l3_imix2_ratio = 4,
+                l3_imix2_size = 570,
+                l3_imix3_ratio = 1,
+                l3_imix3_size = 1518,
+                l3_protocol = 'ipv4',
+                length_mode = 'imix',
+                #mac_dst_mode = 'discovery', # not supported yet
+                mac_src = '00.00.c0.a8.02.03',
+                mac_src2 = '00.00.c0.a8.03.03',
+                pkts_per_burst = '200000',
+                rate_percent = '0.75',
+                transmit_mode = 'continuous',
+                vlan_id = '2',
+                direction = direction,
+                )
+
+    def get_streams (self, direction = 0):
+        return self.create_streams(direction)
+
+# dynamic load - used for trex console or simulator
+def register():
+    return STLS1()
+
+
+
diff --git a/scripts/stl/hlt/hlt_david3.py b/scripts/stl/hlt/hlt_david3.py
new file mode 100755
index 00000000..01bf2431
--- /dev/null
+++ b/scripts/stl/hlt/hlt_david3.py
@@ -0,0 +1,47 @@
+from trex_stl_lib.trex_stl_hltapi import STLHltStream
+
+
+class STLS1(object):
+
+    def create_streams (self, direction = 0):
+        return STLHltStream(
+                l3_protocol = 'ipv4',
+                ip_src_addr = '100.1.1.1',
+                ip_src_mode = 'fixed',
+                ip_src_count = 1,
+                ip_src_step = '0.0.0.1',
+                ip_dst_addr = '200.1.1.1',
+                ip_dst_mode = 'fixed',
+                ip_dst_step = '0.1.0.0',
+                ip_dst_count = 1,
+                l3_length = 474,
+                ip_dscp = 10,
+                #rate_bps = 256000000, # not supported yet
+                mac_src_mode = 'fixed',
+                mac_src_step = 1,
+                mac_src_count = 1,
+                #mac_dst_mode = discovery  # not supported yet,
+                mac_dst_step = 1,
+                mac_dst_count = 1,
+                #mac_src = [ip_to_mac 200.1.1.1] # not supported yet,
+                #mac_src2 = [ip_to_mac = 100.1.1.1] # not supported yet,
+                #mac_dst = [ip_to_mac 100.1.1.1] # not supported yet,
+                #mac_dst2 = [ip_to_mac = 200.1.1.1] # not supported yet,
+                vlan_id_mode = 'fixed fixed',
+                vlan_id = '200 100',
+                vlan_id_count = '1 1',
+                vlan_id_step = '1 1',
+                vlan_user_priority = '3 0',
+                vlan_cfi = '1 1',
+                direction = direction,
+                )
+
+    def get_streams (self, direction = 0):
+        return self.create_streams(direction)
+
+# dynamic load  used for trex console or simulator
+def register():
+    return STLS1()
+
+
+
diff --git a/scripts/stl/hlt/hlt_david4.py b/scripts/stl/hlt/hlt_david4.py
new file mode 100755
index 00000000..9624c0bb
--- /dev/null
+++ b/scripts/stl/hlt/hlt_david4.py
@@ -0,0 +1,49 @@
+from trex_stl_lib.trex_stl_hltapi import STLHltStream
+
+
+class STLS1(object):
+
+    def create_streams (self, direction = 0):
+        mac_dst_count = 10
+        mac_src_count = 10
+        pkts_per_burst = 10
+        intf_traffic_dst_ip = '48.0.0.1'
+        intf_traffic_src_ip = '16.0.0.1'
+
+        return STLHltStream(
+                #enable_auto_detect_instrumentation = 1, # not supported
+                ip_dst_addr = intf_traffic_dst_ip,
+                ip_dst_count = mac_src_count,
+                ip_dst_mode = 'increment',
+                ip_dst_step = '0.0.1.0',
+                ip_src_addr = intf_traffic_src_ip,
+                ip_src_count = mac_src_count,
+                ip_src_mode = 'increment',
+                ip_src_step = '0.0.1.0',
+                l3_protocol = 'ipv4',
+                mac_dst_count = mac_dst_count,
+                #mac_dst_mode = 'discovery', # not supported
+                mac_dst_mode = 'increment',
+                mac_dst_step = 1,
+                mac_src_count = mac_src_count,
+                mac_src_mode = 'increment',
+                mac_src_step = 1,
+                pkts_per_burst = pkts_per_burst,
+                transmit_mode = 'continuous',
+                vlan_id = '50 50',
+                vlan_id_count = '2 2',
+                vlan_id_mode = 'increment fixed',
+                vlan_id_step = '1 1',
+                vlan_protocol_tag_ids = '{8100 8100}',
+                direction = direction,
+                )
+
+    def get_streams (self, direction = 0):
+        return self.create_streams(direction)
+
+# dynamic load  used for trex console or simulator
+def register():
+    return STLS1()
+
+
+
diff --git a/scripts/stl/hlt/hlt_imix_4rates.py b/scripts/stl/hlt/hlt_imix_4rates.py
new file mode 100755
index 00000000..653c3876
--- /dev/null
+++ b/scripts/stl/hlt/hlt_imix_4rates.py
@@ -0,0 +1,23 @@
+from trex_stl_lib.trex_stl_hltapi import STLHltStream
+
+
+class STLS1(object):
+
+    def create_streams (self, direction = 0):
+        return STLHltStream(length_mode = 'imix', rate_pps = 2,
+                            l3_imix1_size = 60, l3_imix1_ratio = 4,
+                            l3_imix2_size = 400, l3_imix2_ratio = 3,
+                            l3_imix3_size = 2000, l3_imix3_ratio = 2,
+                            l3_imix4_size = 8000, l3_imix4_ratio = 1,
+                            l4_protocol = 'udp', direction = direction,
+                            )
+
+    def get_streams (self, direction = 0):
+        return self.create_streams(direction)
+
+# dynamic load - used for trex console or simulator
+def register():
+    return STLS1()
+
+
+
diff --git a/scripts/stl/hlt/hlt_tcp_ranges.py b/scripts/stl/hlt/hlt_tcp_ranges.py
new file mode 100755
index 00000000..31edc61a
--- /dev/null
+++ b/scripts/stl/hlt/hlt_tcp_ranges.py
@@ -0,0 +1,26 @@
+from trex_stl_lib.trex_stl_hltapi import STLHltStream
+
+
+class STLS1(object):
+
+    def create_streams (self, direction = 0):
+        return [STLHltStream(tcp_src_port_mode = 'decrement',
+                             tcp_src_port_count = 10,
+                             tcp_src_port = 1234,
+                             tcp_dst_port_mode = 'increment',
+                             tcp_dst_port_count = 10,
+                             tcp_dst_port = 1234,
+                             name = 'test_tcp_ranges',
+                             direction = direction,
+                             ),
+               ]
+
+    def get_streams (self, direction = 0):
+        return self.create_streams(direction)
+
+# dynamic load - used for trex console or simulator
+def register():
+    return STLS1()
+
+
+