iCalendar Transport-Independent Interoperability Protocol (iTIP) deprecated
General
What's this about
This article will describe how the iTIP protocol was realized, which parts of the protocol are missing and where the implementation differs from the standard.
iTIP
iTIP is a standard. It defines "how calendaring systems use iCalendar RFC5545 objects to interoperate with other calendaring systems"1. So basically it's about how to organize and maintain calendar events across multiple systems.
Transport
The RFC does explicit not mention a specific transport mechanism for iTIP. The provider implementing the RFC is free to choose. Open-Xchange uses mail to realize the iTIP protocol, efficiently implementing iMIP too.
Handled components
The iTIP protocol allows to synchronize following components
- VEVENT
- VFREEBUSY
- VTODO
- VJOURNAL
Currently the Open-Xchange Server will only handle the VEVENT component.
Methods
PUBLISH
The PUBLISH method isn't treated in any special way. A VENENT posted over PUBLISH is handled the same way as a REQUEST.
REQUEST
With the REQUEST method initial invites, updates, rescheduling and more is realized. Many of the functionality mentioned in the RFC is build. Not supported is delegating an event to another CU or forwarding to an uninvited CU.
REPLY
A REPLY normally should only transmit the replying attendee status. Nevertheless some calendaring systems edit other properties too. To avoid, e.g. a changed event title, the server will silently drop all changed properties.
However changed parameters on the attendee object itself will be taken over. As long as the URI of the attendee doesn't change all other parameters can be edited.
ADD
The ADD method is implemented as recommended by the RFC.
CANCEL
The CANCEL method is implemented as recommended by the RFC.
REFRESH
The REFRESH method is implemented as recommended by the RFC.
COUNTER
The COUNTER method is implemented as recommended by the RFC.
DECLINECOUNTER
The DECLINECOUNTER method is implemented as recommended by the RFC.