1 2 3 4 5 6 7 8  1 2 3 4 5 6 7 8  1 2 3 4 5 6 7 8  1 2 3 4 5 6 7 8 
+----------------+----------------+----------------+----------------+
|  authen_method |    priv_lvl    |  authen_type   | authen_service |
+----------------+----------------+----------------+----------------+
|    user_len    |    port_len    |  rem_addr_len  |    arg_cnt     |
+----------------+----------------+----------------+----------------+
|   arg_1_len    |   arg_2_len    |      ...       |   arg_N_len    |
+----------------+----------------+----------------+----------------+
|   user ...
+----------------+----------------+----------------+----------------+
|   port ...
+----------------+----------------+----------------+----------------+
|   rem_addr ...
+----------------+----------------+----------------+----------------+
|   arg_1 ...
+----------------+----------------+----------------+----------------+
|   arg_2 ...
+----------------+----------------+----------------+----------------+
|   ...
+----------------+----------------+----------------+----------------+
|   arg_N ...
+----------------+----------------+----------------+----------------+