Como usar o parâmetro Array/Table para Oracle (ODP.NET 10g) via ADO.NET/C#?

CREATE OR REPLACE package SOME_PACKAGE as
  ...
  type t_number_tab is table of number index by pls_integer;
  ...
  procedure ins_test(i_id_tab in t_number_tab, o_inserted out number);

end SOME_PACKAGE;


CREATE OR REPLACE package body SOME_PACKAGE as

    procedure ins_test(i_id_tab in t_number_tab, o_inserted out number) is
    begin
        -- inserts all records to test table based on incoming table of ids
        forall i in i_id_tab.first .. i_id_tab.last
            insert into TEST_TAB
            (id, val1, val2)
            select id,val1,val2
            from main_tab
            where id = i_id_tab(i);

        o_inserted := SQL%ROWCOUNT;

        commit;
    exception
        when others then
            rollback;
            raise;
    end ins_test;
...
end SOME_PACKAGE;

string connStr = "User Id=xxx;Password=xxxx;Data Source=xxxxx;";
OracleConnection _conn = new OracleConnection(connStr);
_conn.Open();

OracleCommand cmd = _conn.CreateCommand();
cmd.CommandText = "some_package.ins_test";
cmd.CommandType = CommandType.StoredProcedure;

OracleParameter p1 = new OracleParameter();
OracleParameter p2 = new OracleParameter();

p1.OracleDbType = OracleDbType.Decimal;
p1.Direction = ParameterDirection.Input;
p2.OracleDbType = OracleDbType.Decimal;
p2.Direction = ParameterDirection.Output;

p1.CollectionType = OracleCollectionType.PLSQLAssociativeArray;
p1.Value = new int[3] { 1, 2, 3 };
p1.Size = 3;

cmd.Parameters.Add(p1);
cmd.Parameters.Add(p2);

cmd.ExecuteNonQuery();