diff --git a/contrib/simtrace.lua b/contrib/simtrace.lua
new file mode 100644
index 00000000..68eb9610
--- /dev/null
+++ b/contrib/simtrace.lua
@@ -0,0 +1,67 @@
+usb_simtrace_protocol = Proto("USB_simtrace",  "USB simtrace protocol")
+
+
+local control_commands = {
+-- /* SIMTRACE_MSGC_GENERIC */
+[0x0000] = "SIMTRACE_CMD_DO_ERROR",
+[0x0001] = "SIMTRACE_CMD_BD_BOARD_INFO",
+
+-- /* SIMTRACE_MSGC_CARDEM */
+[0x0101] = "SIMTRACE_MSGT_DT_CEMU_TX_DATA",
+[0x0102] = "SIMTRACE_MSGT_DT_CEMU_SET_ATR",
+[0x0103] = "SIMTRACE_MSGT_BD_CEMU_STATS",
+[0x0104] = "SIMTRACE_MSGT_BD_CEMU_STATUS",
+[0x0105] = "SIMTRACE_MSGT_DT_CEMU_CARDINSERT",
+[0x0106] = "SIMTRACE_MSGT_DO_CEMU_RX_DATA",
+[0x0107] = "SIMTRACE_MSGT_DO_CEMU_PTS",
+[0x0108] = "SIMTRACE_MSGT_BD_CEMU_CONFIG",
+
+-- /* SIMTRACE_MSGC_MODEM */
+[0x0201] = "SIMTRACE_MSGT_DT_MODEM_RESET",
+[0x0202] = "SIMTRACE_MSGT_DT_MODEM_SIM_SELECT",
+[0x0203] = "SIMTRACE_MSGT_BD_MODEM_STATUS",
+
+-- /* SIMTRACE_MSGC_SNIFF */
+[0x0300] = "SIMTRACE_MSGT_SNIFF_CHANGE",
+[0x0301] = "SIMTRACE_MSGT_SNIFF_FIDI",
+[0x0302] = "SIMTRACE_MSGT_SNIFF_ATR",
+[0x0304] = "SIMTRACE_MSGT_SNIFF_TPDU",
+[0x0303] = "SIMTRACE_MSGT_SNIFF_PPS"
+}
+
+local msgtype  = ProtoField.uint16("usb_simtrace.msgtype", "Message Type", base.HEX_DEC, control_commands)
+local seqnr  = ProtoField.uint8("usb_simtrace.seqnr", "Sequence Number", base.HEX_DEC)
+local slotnr  = ProtoField.uint8("usb_simtrace.slotnr", "Slot Number", base.HEX_DEC)
+local reserved  = ProtoField.uint16("usb_simtrace.reserved", "reserved", base.HEX_DEC)
+local payloadlen  = ProtoField.uint16("usb_simtrace.length", "length", base.HEX_DEC)
+local payload  = ProtoField.bytes("usb_simtrace.payload", "Data")
+
+usb_simtrace_protocol.fields = {
+  msgtype, seqnr, slotnr, reserved, payloadlen, payload
+}
+
+function usb_simtrace_protocol.dissector(buffer, pinfo, tree)
+  length = buffer:len()
+  if length == 0 then return end
+
+  pinfo.cols.protocol = usb_simtrace_protocol.name
+
+  local subtree = tree:add(usb_simtrace_protocol, buffer(), "USB simtrace Data")
+  local command = buffer(0,2):uint()
+
+  subtree:add(msgtype, command):set_generated()
+  subtree:add(seqnr, buffer(2,1))
+  subtree:add(slotnr, buffer(3,1))
+  subtree:add_le(payloadlen, buffer(6,2))
+  pinfo.cols.info = string.format("Cmd 0x%04X : %s", command, control_commands[command])
+  subtree:add(payload, buffer(8,length-8))
+
+end
+
+
+function usb_simtrace_protocol.init()
+local usb_product_dissectors = DissectorTable.get("usb.product")
+usb_product_dissectors:add(0x1d50616d, usb_simtrace_protocol)
+
+-- DissectorTable.get("usb.bulk"):add(0xffff, usb_simtrace_protocol)
+end