-- works as of Wireshark v0.99.7
do
        local pdm_proto = Proto("PDM", "PDM protocol");
        -- (to confirm this worked, check that this protocol appears at the bottom of the "Filter Expression" dialog)
        -- our new fields
        local tb = ProtoField.string("pdm.tb", "Time Base (Granularity of Time)")
        local scaledtlr = ProtoField.uint16("pdm.scaledtlr", "Scale of Delta Time Last Received", base.HEX, nil, 0x3f80)
        local scaledtls = ProtoField.uint16("pdm.scaledtls", "Scale of Delta Time Last Sent", base.HEX, nil, 0x007f)
        local psntp = ProtoField.uint16("pdm.psntp", "Packet Sequence Number This Packet", base.DEC)
        local psnlr = ProtoField.uint16("pdm.psnlr", "Packet Sequence Number Last Received", base.DEC)
        local deltatlr = ProtoField.uint16("pdm.deltatlr", "Delta Time Last Received", base.HEX)
        local deltatls = ProtoField.uint16("pdm.deltatls", "Delta Time Last Sent", base.HEX)
        -- add the fields to the protocol
        -- (to confirm this worked, check that these fields appeared in the "Filter Expression" dialog)
        pdm_proto.fields = {tb, scaledtlr, scaledtls, psntp, psnlr, deltatlr, deltatls}

        -- declare the fields we need to read
        local original_dstopt_dissector
        function pdm_proto.dissector(tvbuffer, pinfo, treeitem)

                original_dstopt_dissector:call(tvbuffer, pinfo, treeitem)
		local subtreeitem = treeitem:add(pdm_proto, tvbuffer)
		local tb_int = tvbuffer(4,2):uint()/16384
		if tb_int == 0 then
			subtreeitem:add(tb, tvbuffer(), "Timebase: milliseconds")
		elseif tb_int == 1 then
			subtreeitem:add(tb, tvbuffer(), "Timebase: microseconds")
		elseif tb_int == 2 then
			subtreeitem:add(tb, tvbuffer(), "Timebase: nanoseconds")
		else
			subtreeitem:add(tb, tvbuffer(), "Timebase: picoseconds")
		end
			
		subtreeitem:add(scaledtlr, tvbuffer(), "Scale of Delta Time Last Received:", tvbuffer(4,2):uint())
		subtreeitem:add(scaledtls, tvbuffer(), "Scale of Delta Time Last Sent:", tvbuffer(4,2):uint())
		subtreeitem:add(psntp, tvbuffer(), "Packet Sequence Number This Packet:", tvbuffer(6,2):uint())
		subtreeitem:add(psnlr, tvbuffer(), "Packet Sequence Number Last Received:", tvbuffer(8,2):uint())
		subtreeitem:add(deltatlr, tvbuffer(), "Delta Time Last Received:", tvbuffer(10,2):uint())
		subtreeitem:add(deltatls, tvbuffer(), "Delta Time Last Sent:", tvbuffer(12,2):uint())

        end
        local ipv6_nxt_table = DissectorTable.get("ipv6.nxt")
        original_dstopt_dissector = ipv6_nxt_table:get_dissector(60) -- save the original dissector so we can still get to it
        ipv6_nxt_table:add(60, pdm_proto)                 -- and take its place in the dissector table
end