This is a much more modern version of the original GNOME Telephony Application Services Protocols, as proposed for Ubuntu GNU/Linux 10.10 at UDS.

1. Telephony Stack – Problem Space
Desktop
Laptop
Netbook
Touchpad
Devices
Cellphones
Primarily VoIP & IM
Primarily Cellular and SMS
Applications:
* calling
* messaging
* notify and screening
* acd agents & call centers
* relationship management
* address book integration

2. Telephony Stack - Goals
* Unified user experience – does not matter if cellular, voip, isdn, other
Dialing a phone number should always be same regardless of backend
Receiving incoming call as a consistent user experience
Using contacts and address books should be automatic and consistent
* Unified development model – client apps written once to one application family
No need for multiprotocol clients or writing to multiple complex api's
Enable applications development rather than telephony client development
* Single telephony stack that can serve cell phones to desktop
Must be lightweight
* Based on existing packages and components where possible
No need for NIH
* Utilizes Ubuntu desktop elements to improve user experience
Integrates with indicators and osd notify
“Collapse the problem space so that developers can produce
applications for users easily regardless of environment “

3. Telephony Stack - History
* Traditional designs
Protocol specific client; separate client for VoIP, cellular, ISDN, etc
Applications designed around and for specific telephony protocols
Applications involved in low level media issues
* Unified multiprotocol clients
Examples include Empathy and Pidgeon
Support for many protocols build as plugins
Complex configuration for each protocol
Requires media support in client
Complex to build telephony applications outside of client
Client has to be embedded to do basic applications
* Telephony unification started in Lucid
Proposed SIP as universal client protocol
Used sipwitch to route sip requests to various services
Client development has to start as VoIP client

4. Telephony Stack – Forward from Lucid

5. Telephony Stack – ofono proposal bottom-UP
Applications Indicators Configuration Handlers
oFono deamon
oFono Dbus oFono Dbus oFono Dbus oFono Dbus
GSM lmodem
SIP &
RTP
Audi o & Mic
VoIP provider
or optional
Sipwitch

6. Telephony Stack – wed. UDS
Applications Indicators Configuration Handlers
Telepathy daemon over Dbus
VoIP
Service
Chat
Services
oFono
Service
oFono Service daemon
over Dbus
GSM
Service
Linmodem
Service
SIP Witch
over SIP +
Telepathy cfg
SIP Providers
SIP Peers
Local IP-PBX

7. Telephony Stack - Discussion
Do either architectures make sense?
Which is most appropriate long-term for Ubuntu?
What are the other options to consider?
What are the problems & limitations that remain?