SAP Networking Explained: The Router and Gateway Magic

Not only sometimes to internal communication, also to the public. Because to be honest, for for someone who just do network stuff, SAP is really a black box. You have no understanding of the service and how should you? That's a whole business world where you have tons of different silos like and developers engineers administrators and stuff. They do only SAP. How should you as a network guy who has another silo by the way, um, take care of that SAP stuff? That's like if someone asked you to run the whole IT and you have skills of everything. That's impossible. And when you look at all those services, I just picked a few and let's grab for example that SAP router.

So, what SAP had, think about many years back when you had just a modem and you tried to reach another system over the internet. So, the problem is if you now have, I don't know, maybe 50 or 100 SAP systems, you need to expose all those ports. And they maybe collide with each other because they're the same port number. So, you cannot all expose them on the same IP address and getting an IP is a bit difficult, especially in the meantime for IPv4. So, what SAP does is say, "Hey, we have a great idea. Let's build a service which listens on one port and on client side you specify just I want to connect to the like application

gateway and this one then just redirects internally and allows you to access the other system through that single port."