How to track recieved SMS?

[Praveen .K.R]

Hi all

   I am able to send and recieve sms through gateway which is working
fine. But, the problem i was facing is the to which the reply(recieved
sms) was. Like 1:1 mapping. Is there any functionality like id for
each sms that i send and the reply should be done through that id
which is invisible for end user.