this is a tipical mts configuration:

mts_dispatchers="ipc,1"
mts_dispatchers="tcp,9"
mts_max_dispatchers=30
mts_servers=9
mts_max_servers=100
mts_service=****
mts_listener_address="(ADDRESS=(PROTOCOL=ipc)(KEY=***))"
mts_listener_address="(ADDRESS=(PROTOCOL=tcp) (HOST=****) (PORT=*****))"

your listener may look like this:
LISTENER =
(ADDRESS_LIST =
(ADDRESS=
(PROTOCOL=IPC)
(KEY= ****)
)
)
(ADDRESS =
(COMMUNITY = ******)
(PROTOCOL = TCP)
(Host = smt570) #senza Keon
(Port = 1521) #senza Keon
.....etc..etc.
Your IPC protocol (in your listener, must be before the TCP specs)