ATM Interface problem (TCServer+Listener)

We have got a problem with our system where the transaction time is on an average 15 sec, where the default time should be less 2 seconds. We are using 8583 message format at the ATM switch end and at the t24 end using listener & tcserver as part of the t24 ATM interface.

I am new here so might ask as a dump.

Thanks in advance.

There are many things which you need to check
1. Server Specs
2. Total Number of Transactions
3. ATM Interface Tuning
4. Involvement of Third party solutions between interbank transactions

etc

T24 ATM interface for our bank has been fixed many times by t24.