Support of gRPC by Edge SWG (formerly ProxySG)

Products

• ProxySG Software - SGOS
• ISG Proxy

Issue/Introduction

As a proxy admin, you've been tasked with determining if gRPC services are supported through Broadcom Edge SWG (formerly ProxySG) appliances.

For background, gRPC related services are designed to function via HTTP/2, which is a major revision of the HTTP network protocol used by the World Wide Web. Despite the current limitation that gRPC services cannot be directly called via today's web browsers, two common approaches exist that allow gRPC use via browser app:

1. gRPC-Web - Allows browser apps to benefit from the high-performance and low network usage of gRPC. Not all of gRPC's features are supported by gRPC-Web. Client and bi-directional streaming isn't supported, and there is limited support for server streaming.
2. RESTful JSON Web APIs - This allows an app to support both gRPC and JSON web APIs, without duplicating effort of building separate services for both.

 

Resolution

Since gRPC simply defines a protocol over HTTP/2 via headers and data, gRPC services are expected to function on appliances running versions of SGOS that include support for HTTP/2 (SGOS 7.1.1.1 or later). This remains valid as long as the gRPC calls adhere to HTTP/2 standards appropriately. 

Additional Information

• For information on HTTP/2 support by ProxySG and Proxy ASG appliances, refer to Article 174021.
• For more information on the gRPC implementation refer to the following external vendor documentation:
  • Github - gRPC over HTTP2
  • Microsoft - Compare gRPC services with HTTP APIs