So this is more about ports and communication with respect to a ABAP NETWEAVER SETUP and these are pretty basic things that we would be discussing. This is for complete beginners who have no clue about networking.
As a BASIS Consultant you will encounter this multiple times in your life that you need to raise a ticket to your OS Team or SM Team to assign a port to a service or to open a port.
Ever wondered what this port is and what is its need ?
Do this before reading forward ,
Open command prompt in your windows as an administrator and get result of netstat -ab , you will get a list like this (Google your option if using any other user)
I highlighted the port number, things that comes after the IP, you can notice that we have the same IP and different port numbers for different services . Understand this like IP is your building (SAP SYSTEM) with multiple flats in which different flats , different services reside.
Let's understand using this figure : (Click on Image)
Now I would like to add one small point. We have two types of ports : Internal and External.
As the name suggests, Internal ports are used when processes are having communication internally like Dispatcher connecting with the Gateway.
The following ports are used internally on the AS for ABAP.