How to configure IDOCs between 2 servers

Hi,i am an ABAP consultant and for some reason i was charged with configuring IDOCs between 2 different servers, i have been trying all tutorials that i could find for the past 2 weeks but i always get stuck in creating the partner profile step, most of the time i get an error "port could not be opened", also the tutorials i tried were never crystal clear about which steps to be configured on the sender server and which steps to be done on the receiver server, plus all the tutorials i tried never said the possible issues that could occur during configuration or how to fix them, so my question is could someone direct me to a comprehensive tutorial that is clear enough to be followed and also has tips on how to handle the possible issues that could happen during configuration i would be so thankful