V$MTS

Columns
   ___________________________
 
   SERVERS_HIGHWATER
   MAXIMUM_SESSIONS
   MAXIMUM_CONNECTIONS
   SERVERS_TERMINATED
   SERVERS_STARTED

Related Views:

V$CIRCUIT 
V$DISPATCHER 
V$DISPATCHER_RATE 
V$QUEUE 
V$REQDIST 
V$SHARED_SERVER 
V$THREAD