^ Is it you or a senior who require this facility?
There is actually nothing like a a porter service at the INTL airport, even if its there, hardly you find them there to help out; provided you ask the airline that your coming in from the INTL route this is of no help!
If its you , the distance between the Intl airport and domestic isnt ay too much, you can lug a cart full of you luggage to the domestic terminal!