What is Azure Relay?
The Azure Relay service enables you to securely expose services that run in your corporate network to the public cloud, without opening a port on your firewall or making intrusive changes to your corporate network infrastructure. The service supports traditional one-way, request/response and peer-to-peer communication, event distribution at internet scope for publish/subscribe scenarios, and bi-directional, unbuffered socket communication across network boundaries.
Azure Relay differs from network-level integration technologies such as VPN. A relay can be scoped to a single application endpoint on a single machine, whereas Microsoft describes VPN technology as far more intrusive because it alters the network environment.
Core Features
Hybrid Connections: The secure, open-protocol evolution of the earlier relay features. Hybrid Connections are based on HTTP and WebSockets, work on any platform and in any language, and are compatible with the WebSocket API in common web browsers.
WCF Relays: The legacy offering for WCF programming models. A suite of WCF relay bindings creates the connection between the on-premises service and the relay service.
Outbound connection instead of open ports: The on-premises service connects to the relay service through an outbound port and creates a bi-directional socket, through which the relay service forwards client data.
Shared gateway: Hybrid Connections and WCF Relay exist side by side in the Azure Relay service, share a common gateway and are otherwise different implementations.
Typical Use Cases
Hybrid applications: A cloud application reaches a service that still runs in the datacenter, such as a legacy system, without opening inbound ports.
Modernization with a WCF estate: Existing WCF services stay on premises and become reachable for clients outside the network through WCF relay bindings.
Event distribution: Publish/subscribe scenarios with event distribution at internet scope.
Cross-platform integration: Hybrid Connections work with any WebSocket library in .NET, Node.js or Java.
Benefits
- No inbound firewall ports and no intrusive changes to network infrastructure
- Scoping to a single application endpoint instead of network-wide coupling as with VPN
- Open protocols in Hybrid Connections and therefore broad platform and language support
- Continued operation of existing WCF programming models through WCF Relays
- The client needs neither a direct connection nor knowledge of the on-premises service location
Integration with innFactory
As a Microsoft Solutions Partner, innFactory supports you with hybrid integration scenarios using Azure Relay: choosing between Hybrid Connections and WCF Relay, securing endpoints, defining an operating model, and comparing alternatives such as Private Link, VPN Gateway or ExpressRoute.
Contact us for a no-obligation consultation on Azure Relay.
Typical Use Cases
Technical Specifications
Frequently Asked Questions
What is Azure Relay used for?
Azure Relay securely exposes services that run in your corporate network to the public cloud, without opening a port on your firewall or making intrusive changes to your corporate network infrastructure.
What is the difference between Hybrid Connections and WCF Relay?
Hybrid Connections are based on open standards, use HTTP and WebSockets, and work on any platform and in any language, including .NET Core, .NET Framework and JavaScript/Node.js. WCF Relay is the legacy offering for the full .NET Framework and WCF programming models and uses a suite of WCF relay bindings.
How does Azure Relay differ from a VPN?
Azure Relay operates at the application level: a relay can be scoped to a single application endpoint on a single machine. According to Microsoft, VPN technology is far more intrusive because it relies on altering the network environment.
Do inbound firewall ports need to be opened?
No. The on-premises service establishes an outbound connection to the relay service. The client sends traffic to the relay service, which relays data to the on-premises service through the bi-directional socket. The client needs neither a direct connection nor knowledge of the service location.
Does Azure Relay replace BizTalk Services Hybrid Connections?
Yes. According to Microsoft, Hybrid Connections of Azure Relay replaces the old Hybrid Connections feature of BizTalk Services, which was built on the Azure Service Bus WCF Relay.
Note: All product information on this page has been compiled with care, but is provided without guarantee and may be outdated or incomplete. Cloud services evolve rapidly — features, pricing, SLAs, and availability change frequently. Authoritative and up-to-date information can only be found on the official product page of Azure (official documentation). This page does not represent an offer by Azure.
