[Dev] Re: Free/busy idea

[Lisa Dusseault]

Although there isn't a standard for sharing free-busy, CalDAV is a 
proposed standard and it does have a way to solve this.  If the client 
decides to upload a calendar to the CalDAV server, then the server is 
responsible for aggregating all the events and providing a freebusy 
"report" to authorized users.

There's even a way for users to put blocks of free-busy time into this 
system that don't correspond to events (or that correspond to private 
events that the user does not wish to share):  The client can upload 
"blank" events (these are called VFREEBUSY components) to the CalDAV 
server, and these are included in the report.

One of the benefits of the server generating the report is that it can 
do so for only a day or a week period under examination.  A 
peer-to-peer or dumb-storage solution (without server logic) requires 
the clients to upload and download larger chunks of  free-busy 
information (although I'm not sure there's sufficient evidence of real 
performance problems in that depending on how clever we make the 
publish algorithm).

Another benefit is that in the long run there are good signs that this 
will be the standard solution, workable not just for Chandler <--> 
Chandler but also to get free-busy information for Sunbird users with 
known CalDAV server locations, or to use a CalDAV gateway that extracts 
free-busy information out of an Exchange system.

I believe this is a pretty expedient thing for us to do even in 0.6 -- 
it makes free-busy information available for download with little more 
upload work than we already do, and it does require some server support 
but I think we can do that.  There are certainly arguments against 
relying on server logic -- the added dependency for the schedule in 0.6 
for example -- and we can well hash those out as well as the benefits.

http://ietf.webdav.org/caldav/

Thx,
Lisa

On Feb 11, 2005, at 11:58 AM, Bryan Stearns wrote:

> After a brief conversation with Mimi and Sheila this morning about 
> free/busy, I had an idea and wrote it up here:
>
> http://wiki.osafoundation.org/bin/view/Journal/FreeBusyStrawMan
>
> Comments welcome.
>
> ...Bryan
>