Load balancers. These are used to distribute traffic to virtual machines in the application-tier subnet. For high availability, use the built-in SAP Web Dispatcher, Azure Load Balancer, or network appliances, depending on the traffic type (such as HTTP or SAPGUI) or the required network services, such as Secure Sockets Layer (SSL) termination.
Reference:
https://docs.microsoft.com/en-us/azure/architecture/reference-architectures/sap/sap-netweaver