VISSv2

VISSv2

This page highlights the major differences between VISS version 1 (v1) and version 2 (v2).

see also "Gen2" roadmap (VISSv2 had operational name of Gen2 for second generation)

Specifications

• VISS v1 as published at W3C
• VISS v1 Editor's draft, no major changes

• VISS v2 Core Editor's draft
• VISS v2 Transport Editor's draft

The underlying data model VSS was also refactored for its second major version, primarily for representing multiple instances of eg wheel, door with additional improvements such as array support. @@get summary of major changes.

• VSS

Access Control

While VISS v1 included wording on requiring access control for safety and security consideration, it was deemed out of scope and implementation specific.

v2 has defined Access Control as there are clear benefits for consistency in various aspects such as authentication methods and behavior to be able to create cross-vehicle applications.

Subscription

Several improvements were made to the subscription service filtering capabilities in v2 as there were rather rudimentary in v1.

• History
• Curve logging
• further path (tree) based filtering
• adding metadata

v1 filtering defines:

• time interval
• delta change

Protocols

HTTP

A HTTP (REST interface) was desirable as often a client may only needs to access specific signals once or infrequently which is facilitated with a REST interface instead of opening a WebSocket and making a subscription. Specifically protocol used is HTTPS for TLS protection.

HTTP section of VISSv2

MQTT

MQTT - VISS over MQTT experimental support is operational in open source version but we are not settled on architecture for including MQTT, want to learn from industry trend before adding to specification.