Telephony Stack Options and Applications

Registered by Alexander Sack

The UDS session for this spec is to discuss options we have to standardize and unify the telephony stack in the linux ecosystem in general and for Ubuntu in particular.

This spec explores how to integrate oFono middleware in the existing telephony stacks available, to evaluates how the telephony stack can be improved in general, and how we can unify the software, application development, and user experience of both telephony and VoIP. In particular this spec intends to address those steps we can take in Maverick to further this goal.

Not covered this cycle: While we looking at further integrating telepathy as the primary means of application delivery, we are also looking how to resolve some long-standing problems in SIP and VoIP integration for which we are using SIP Witch as per Lucid. Questions of VoIP integration include issues such as support for multiple devices, being able to perform selective routing based on service availability, smart use of NAT, simplification of configuration,and integrating such support with existing VoIP clients broadly, including improving the telepathy user experience for VoIP.

Blueprint information

Not started
Alexander Sack
Alexander Sack
Needs approval
Tom Gall
Series goal:
Accepted for maverick
Milestone target:
milestone icon ubuntu-10.10

Related branches



[asac Jun 10] telepathy-ring etc. should be now in my ppa and also uploaded to archive.
[asac Aug] tom taking over this spec. thanks!
[tom-gall Aug] grabbing
[tom-gall Aug] CDMA, EVDO and LTE via ofono is not currently implemented
[tom-gall Aug] Howto with phonesim assembled at
[tom-gall Aug] Trying to obtain a telet EVK2 kit with GC86x chipset (864 hopefully)
[tom-gall Aug] n900 will be obtained, ofono backend support is included with the n900, gated until it arrives.
[asac Aug] moving work items to final as hardware allocation is ongoing.
[tom-gall Oct 26] n900 received

getting n900 hardware; collecting drivers and kernel

Work Items (maverick-alpha-2):
reach out for partners, modem vendors and middleware experts to find suitable hardware to exercise this spec: DONE
ensure that ofono in archive is modern enough for telepathy-ring: DONE
identify other minimum package requirements for telepathy-ring (dependencies, minimum versions, etc.) and make a plan to fulfill those requirements in the archive: DONE
coordinate with stakeholders of the software stack components touched for this specification: DONE
ensure that minimum package requirements are fulfilled in archive; this involves updating packages required for telepathy-ring: DONE
package and stabilize telepathy-ring: DONE

Work Items (maverick-alpha-3):
initiate discussion with empathy developers on what can be achived this cycle: DONE
integrate dialer application from empathy (via tel account supplied by telpathy-ring: DONE
or develop a simple dialer on our own: POSTPONED
package and make dialer available in the archive (via telepathy-ring): DONE
setup protocol schemes and hook that up to the dialer: POSTPONED

Work Items (ubuntu-10.10-beta):
ensure ofono backend exists for selected modem: DONE

Work Items:
get access to usb modems that can do voice calls (GSM ): DONE
make a ofono build available that supports the modem selected above: TODO
document how to setup software and hardware stack to run this experiment: TODO

--- old comments ---

dyfet - action items for this blueprint from Friday:
* linmodem oFono backend (David Sugar)

dyfet - action items from Thursday's meeting:

* Design indicators (design team - Ken Van Dine)
* Configuration (pushed though telepathy and needs to be merged into sip witch) + UI
 - Related to polishing SIP backend (David Sugar)
* Handlers: address book [could be better - hook-up to address book UIs]
* Accept sip uri and mimetypes and start the appropriate thing (spits it out into indicators) NEEDS HANDLER that talks to Telepathy vs D-bus (David Sugar)
* oFono - Available modem hardware and if oFono works on that hardware (David Bensimon)
* Schedule for open sourcing telepathy oFono hook in (Robert McQueen)
* Contact SFL asking for assistance for writing telepathy backend for IAX2 protocol support (David B.)
* Polishing SIP service backend (David Sugar)
* Need someone to go over sip stack and decide if we use exosip or sophia-sip (David Sugar, ??)
* Need dialer/call UI on top of Telepathy (session on May 14th)

discussion items from Thursday's meeting:

* Need for work on collecting SIP presets to enhance out of box experience
* oFono has planned to implement making calls through your computer controlling a cellphone via BT/USB

Possibly: work on collecting SIP presets to enhance out of box experience
dyfet - based on the UDS discussions so far on wed., I have drawn a new diagram to summarize what we concluded. What is not shown is how sipwitch might receive each user's VoIP account information from the telepathy framework. This may happen over Dbus messaging, or it may happen by telepathy exporting sipwitch configurations.

dyfet - I have posted the UDS gobby notes into the design spec wiki page.

dyfet - I have some thoughts on this I am happy to share in some slides. Mostly these slides will be useful in understanding some of the ideas I am thinking about and some ideas that will get discussed.

asac - first discussion, then drafting and spec.

Is this really an "arm" specific spec?

The precursor to this blueprint may be found at

These are some preliminary proposed work items. This initial list presumes that for Maverick the primary focus will become completing VoIP aspects of the stack, and that ofono related work will most likely not appear until M+1. Hence it may be completely changed as result of UDS discussions.

Some suggested work items based on UDS (the real ones are on top now; these are kept for future work):
Discussion on proposed stack: DONE
Use upstart in sipwitch [1 day]: TODO
Telepathy SIP stack work: TODO
Sipwitch/Telepathy SIP integration: TODO
Telepathy oFono backend: TODO
oFono Linmodem backend: TODO
URL Handler for sip: uri's: TODO
Addressbook handler improvements: TODO

telepathy-ring has been open-sourced:


Work Items