SMPP keep alive.

hi all,
i am connected to a ericsson SMPP server, when a message is sent to my box from a mobile phone it take a long time for my box to receive it. when i look at the SMSC's error log i see where my service is logged off ever 60 seconds for about 20 seconds long. when i reconnects my server finally gets the message. i have my keep alive to 20 seconds  but the connection still disconnects. no matter what i set the keep alive to the server still goes down. however is the service say disconnected and i send a PUSH sms, the messages leaves my server immediately, and the server still does not say connected for another 30 seconds.
anyone knows why this is happening? is it possible to remove the timeout from the SMSC?