6.1 Introduction

The WebSocket protocol enables two-way communication between client and server even when a firewall and/or NAT are present between them. This means, once a WebSocket connection is established, request (and response) primitives can be exchanged in both directions, from the client to the server and vice versa. However, AEs may be capable of handling Notification request primitives only, or no request primitives at all.

WebSocket binding applied by oneM2M entities/nodes shall be fully compliant with IETF RFC 6455 [1]. After establishment of a WebSocket connection between two nodes, at the transmitter side each individual request and response primitive is mapped into one or several WebSocket frames.