[amuwsdv@ammvpdv amuwsrt01]$ lsnrctl status LISTENER_AMUWSDV

LSNRCTL for Linux: Version 10.1.0.5.0 - Production on 23-JAN-2008 20:50:15

Copyright (c) 1991, 2004, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ammvpdv.am.kwe.com)(PORT=1526)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER_AMUWSDV
Version                   TNSLSNR for Linux: Version 10.1.0.5.0 - Production
Start Date                23-JAN-2008 20:10:39
Uptime                    0 days 0 hr. 39 min. 36 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      ON
Listener Parameter File   /amuwsdv01/app/oracle/product/10.1.0se/network/admin/listener.ora
Listener Log File         /amuwsdv01/app/oracle/product/10.1.0se/network/log/listener_amuwsdv.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ammvpdv.am.kwe.com)(PORT=1526)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1526)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

SQL> show parameter service_

NAME                                 TYPE
------------------------------------ ---------------------------------
VALUE
------------------------------
service_names                        string
amuwsdv.am.kwe.com

AMUWSDV.AM.KWE.COM =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = ammvpdv.am.kwe.com)(PORT = 1526))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = amuwsdv)
    )
  )

SID_LIST_LISTENER_AMUWSDV =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /amuwsdv01/app/oracle/product/10.1.0se)
      (PROGRAM = extproc)
    )
  )

LISTENER_AMUWSDV =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = ammvpdv.am.kwe.com)(PORT = 1526))
      )
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1526))
      )
    )

[amuwsdv@ammvpdv admin]$ sqlplus system@amuwsdv.am.kwe.com

SQL*Plus: Release 10.1.0.5.0 - Production on Wed Jan 23 20:58:00 2008

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Enter password:
ERROR:
ORA-12514: TNS:listener does not currently know of service requested in connect
descriptor