SIMPLE Drafts

1
SIMPLE Drafts

• Jonathan Rosenberg
• dynamicsoft

2
Presence List Changes

• Terminology change
• Presence List Information Data Format
• Provides version, full/partial flag
• Lists can contain lists
• List server subscribes to list package for each
  entry, since it doesnt know whether its a list

3
Issue 1 Template or not?

• Template Package
• Collection
• Represents a list of elements for a package
• Might be useful for mwi multiple inboxes
• Would a new body type be needed for each
  templated package?
• Seems wasteful

• Proposal
• Make it a template class
• Mandate multipart/mixed base class mandatory
  type
• Define headers/body type that JUST conveys
  version/partial information
• Dont munge original document
• Specify requirements on packages that can be
  templated
• Must provide URI for element about which document
  contains state

4
Example Message
NOTIFY sipsubscriber_at_example.com
SIP/2.0 Content-Type multipart/mixedboundary---
Content-Length --- Content-Type
application/versioninfo Content-Length
Version 1 State partial --- Content-Type
application/cpim-pidfxml Content-Length
ltPIDFgt
5
Issue 2 Too Many Choices

• Current Draft allows
• PIDF
• Can just pass on content received from downstream
  PA
• Versioning issues
• PLIDF
• Versioning/state flags there
• Requires munging XML breaks signatures
• Multipart Mixed
• Multiple documents unmodified
• Versioning issues
• Partial/full flag missing

• Collection Template Proposal Solves this
• Only mixed
• Define a new type (listinfo) that conveys state
  and version

6
Issue 3 State of subscriptions

• PLS passes state of subscribed entities to
  subscriber
• What about state of those subscriptions?
• Would like to know that a buddy on the list has
  rejected the subscription
• Normally contained in Subscription-State header
• Cant use that

• Proposal
• Place information is listinfo format!
• Listinfo can contain an entry for each element in
  the list
• For each entry, it indicates state of
  subscription to that entry
• Support partial updates for that list

7
Issue 4 Sharing of versions

• Current draft shares version numbers across
  PIDF/PLIDF
• Seems wrong
• This is fixed with listinfo proposal

8
Issue 5 Which package does PLS Use?

• How does PLS know whether to use presence or
  presence.collection for each list entry?
• Solutions
• 1 Try presence.collection, fallback to presence

• 2 List URIs have syntactic sugar to indicate
  that they are lists
• 3 User has to know that they are lists
• 4 Server OPTIONS the URI once, then uses
  appropriate package
• Assumes it cant change roles
• Proposal
• Not 2

9
Data Requirements
10
Problem Statement

• Presence and IM Systems make use of several data
  elements
• Buddy list
• Authorization Datum
• Allow list
• Deny list
• Logic
• Need to manipulate these, interact with them

11
Buddy List Model
SUBSCRIBE --------

---------------gt Read
PA
lt-- //----\\
lt---------------
NOTIFY
-------- --- \\----//


Storage


--------
Server ------gt

Write \ /

\------/
--------



BL

Manipulations



V

--------
Client




--------

12
BL Requirements

• Write Manipulations
• Create, add user, delete user, modify user, clear
  all, delete list
• Read Manipulations
• Read list
• Caching
• Client can store copy
• Modify while offline
• Resync with master copy in network
• Security
• Authentication, privacy, integrity

13
Authorization Model
List2
PA
List1
Logic Script
Data Manipulations
14
Auth Requirements

• Write Manipulations
• Create, add user, delete user, modify user, clear
  all, delete list
• Create/modify/delete logic
• Read Manipulations
• Read list/logic
• Caching
• Client can store copy
• Modify while offline
• Resync with master copy in network
• Security
• Authentication, privacy, integrity

15
General Problem Here

• Application has a number of data elements
• Each has a name
• Each has a type
• List
• Blob
• Client needs to manipulate data elements
• Type specific write/read operations
• Caching
• Security, etc.
• Client binds app data elements to instances of
  the appropriate types

16
Model
Example Application
--------------------------------
---



baz
-


foo bar

-- ----


---- /------ --- ---------
/

/
/

/
/

/
---------/---------------V-----
------------------
/ -- --- -
V B E

-- -- ----
A
G
--
--
-
C V
--
-

object ----

pool D F
----

-


-------------------------------------------------
Data
Storage
17
Open Issues

• Do enough RPC type operations fit under data
  manipulation to merit this approach?
• Not clear yet in the case of conference control
• Answer is yes if its represented through policy
  objects
• Should we go for the general solution or specific
  one for BL/auth?
• Alignment with SIP conferencing work is essential
• Adopt as a work item?