Where can I find SCTP Data Chunk in Dissector Table?

Dear all!

I would like to write a chained dissector for SCTP Data Chunk but I don't know how can I reach it in the Dissector Table. I know I can do this with SCTP like this:

first: ether_table = DissectorTable.get ("ethertype") original_dissector = ether_table:get_dissector(0x84)

then in the definition my dissector:

original_dissector:call( buffer, pinfo, tree )

finally:

ether_table:add (0x84, mydiss)

But I cannot dissect an SCTP Data Chunk in a way like this. The Data Chunk looks in wireshark like a different protocol with its own grey trail and treeview. The payload protocol identifier of sctp finds out the real protocol of the data chunk.