Let's Trouble Shoot Dedicate Server Problem !!!

Dear Sir:

    Our system is OpenVMS 7.1, Oracle 7.3.3.4. We don't use MTS, we only have didicate server because our system is only for Fab server operation and for performace issue.

    We have met a problem these days about dedicated server. We found some times
system increasing to 300 dedicate servers. And these server did not disappear,
CPU time usage is zero. But these server really consume system memory resource.
I must manual kill such processes. I think It is not a normal case. I am crazy
for such condition!!

    I had query v$session, v$process, I found only 20 processes, but I found there are double count or more dedicate server (sometimes to 300) processes in system. I don't know why??

    By the way, I do some test about db-link. If I use db-link to access this database. System will fork one dedicate server to service this connection.
But I query v$dblink, there is no any record in this table??? But when I leave from SQL*Plus, this dedicate server process will automatic exit. I think it is normal!!

    How can I trouble shoot it!! is this a db-link problem?? or some parameter
must be set (I had set sqlnet.ora expiretime parameter to 10)??? please tell me, If you have such experience, thanks a lot!!!

Regards,

                                Roger Li