1. Jonathan Rosenberg dynamicsoft
SIPPING Work Items
Jonathan Rosenberg
dynamicsoft

2. Registration Event Package Changes
Add shortened event
Indicates a decrease in registration interval
Client should re-register before new expiration
Includes an expiration parameter

3. Open Issues Counter-arguments
Default expiration matching default registration expiration
Change to 4200s
XML vs. sipfrag
Why convert reg message to XML?
Answer: separate data from protocol
There is data in XML not in registration
Registration data can change through non-SIP means (administratively)
Example: shortening of registration
Counter-arguments
Size overhead
No need for XML abstraction for simple data

4. App Interaction Who are we? What are we doing?
Cullen Jennings, Eric Burger, Robert Fairlie-Cuninghame, Jonathan Rosenberg
What are we doing?
Stimulation with SIP!
The way in which users interact with applications using stimulus
Media
Markups
DTMF

5. What have we produced? Draft-rosenberg-sipping-app-interaction-00
Overall framework
Draft-burger-sipping-kpml
Keypad Markup Language
Think HTML for black phones
Draft-jennings-sipping-app-info
SIP extensions for the framework
Draft-culpepper-sipping-app-interact-reqs
Top level requirements

6. Open Issues The infamous SIP v. HTTP Debate
Sending the results of a user keypress between a user interface and the application
Interface between apps and UI don’t depend on the type of UI (HTML, VoiceXML) -> HTTP
Security problem -> SIP
Quarantine -> SIP?
Routing argument -> SIP
This is a synchronous operation -> HTTP, but do we care?

7. Focus Determination for KPML
When a user enters a digit, which KPML amongst the ones from the various apps does it apply to?
No way to know for sure
Current draft says send it everywhere – same as the PSTN
Provides a central controller model to deal with cases where a single provider knows the rules
Is that adequate?

8. KPML Post data in HTTP URI or Body
<assuming HTTP>
HTTP allows both. Does it matter.

9. Error Reporting for App-Info
What if the App-Info URI is invalid?
If the header appears in a request, you can reject the request with some error code
But we allow it in responses….
Options
No error reporting
Only send App-Info in requests
Error reporting URI (infinite recursion problem)

10. Indicating Script Termination
If the user dismisses a UI component, there is no way for the application to find out
Same is true in the web, but…
Is this limitation OK for us?
If not, we need to wrap app interactions in dialogs

11. Barge
Framework has a very cool feature that allows IVR barging to be pushed to the endpoint
KPML includes a barge parameter that causes media to be dropped when a regular expression is matched
Means zero-latency barges in IVR – better than PSTN
Problem: how to detect when its OK to start playing media again?
Need some kind of media stream synchronization
Marker bits -> don’t work
PT changes -> might work
Others?

12. Too many solutions?
Framework provides multiple ways to do the same thing
Main one: Composition Model
Model I: Pipe-and-filter
Model II: Central Server
Model III: Endpoint Controlled
The ones that can be used depend on endpoint capabilities, introducing capability determination requirements

13. Hookflash Should hookflash be added to KPML as an event? Opinions?
Its been made “historical” in ISDN and other places
If it knows enough to distinguish clear from hookflash, its functional and can send the right functional message
This is a fallacy I think
Opinions?