What is Azure Relay?
What is Azure Relay?
Azure Relay is a service that enables secure cloud connectivity for enterprise services running on corporate networks. It eliminates the need for opening a port in the firewall or making changes to the network infrastructure. Azure Relay can be described as a short hop service.
Azure Relay supports three different scenarios, which can be described as follows:
- One-way or peer-to-peer communication
- Event distribution within the internet
- Unbuffered socket communication
Azure Relay is often confused with VPN services. While there may be some similarities, they operate on completely different principles. VPN technology allows for multiple interventions, whereas Azure Relay services have a single endpoint. Additionally, network environment changes are not possible with Azure Relay, unlike in VPN. However, Azure has an application that follows a similar structure to VPN called Azure VPN Gateway. For more detailed information on this topic, you can refer to our article titled “What is Azure VPN Gateway?”.
There are essentially two types of Azure Relay services. The first one is Hybrid Connections, which operates based on HTTP and WebSockets protocols. It utilizes these protocols for sending requests or receiving responses. The other service is called WCF Relay, which works with NET Framework or Windows Communication Foundation (WCF). This allows users to enable remote procedure calls using WCF.
One of the main reasons Azure Relay is widely preferred today is its hybrid connectivity structure. This feature allows for secure and open protocol usage during the transition. Additionally, it can be chosen in any desired language on all platforms. Furthermore, the hybrid connectivity feature of Azure Relay has replaced the previously used BizTalk Services. In other words, Azure Relay can be considered as an improved version of BizTalk Services built on top of WCF. Reference
The working principle can be summarized as follows: A service running on a corporate network connects to the Relay structure just like going out to the internet in a standard way. Then, a bi-directional socket is established. This socket is created with the consideration of being associated with a specific address. Afterwards, the client sends a request to the Relay service to reach the desired service. This is where the Azure Relay service comes into play and forwards the request to the on-premises service without the need for opening a port.
