SIP on Kindle

[jmseight]

Hi All,

I read in the forum that there are some interest in making SIP client on Kindle, like port of sjphone. Since the K3 has mic and speaker, is this feasible?

Has someone done it already?

This would be an excellent hack.

Thanks,
James

[knc1]

Originally Posted by jmseight

Hi All,

I read in the forum that there are some interest in making SIP client on Kindle, like port of sjphone. Since the K3 has mic and speaker, is this feasible?

Has someone done it already?

This would be an excellent hack.

Thanks,
James

Your info block reads "Kindle 3G" and your question above mentions the "K3 with mic and speaker" so I think my machine is similar to yours.
A Kindle (3) Keyboard with 3G modem/radio.

Session Initiation Protocol (SIP) protocol is an Application Layer protocol which may be used for many purposes, but since you mention a SIP phone application....

First related question: Can we make a cell phone call over the built-in 3G modem/radio?

Fast answer: No.
The AnyData modem/radio as used in the K3-Keyboard model does not have the voice services included in its firmware.

Can the modem/radio firmware be changed?
Fast answer: Not likely.
The "second ARM" of the K3-Keyboard uses a cryptographically signed firmware image. It is unlikely that this can be "broken" or "worked around".

SIP being an application level protocol does not depend on the transport layer it is riding on, so...

How about SIP/VoIP over the 3G data channel?
Short answer: Not practical.
Technically possible but in practice, the traffic of the 3G data channel is under the control of the provider and the provider's client (Amazon). These controls are highly automated and operate in real time.
So unless Amazon announces they will allow this as general use of the "Free 3G" it is probably just a waste of time to develop.

How about SIP/VoIP over the Wifi radio?
Short answer: N/A no short answer for this one, sorry.
If you have access to a fast enough Wifi access point, then this could be made to work.
In fact, the Wifi communications of the K3-Keyboard can be faster than the data channel provided by the AnyData modem/radio.
Note that the majority of the "Free Wifi" access points provided by AT&T (and other carriers) will be too slow for decent quality VoIP.

Since your post mentioned a 'phone application, I answered that first, but there are other possibilities...

How about SIP/SMS?
The result would be a multipoint IM communications similar to a Jabber "Conference Room".

SIP/SMS over the 3G modem/radio:
Short answer: Possible but subject to provider and provider's client controls (see above).
This could be implemented over either the SMS channel or the Data channel provided by the AnyData modem/radio.


SIP/SMS over the Wifi:
Short answer: Possible and Practical.

SIP/<something else>
What else did you have in mind?
Maybe I can answer that question(s).

External ref:
http://www.sipknowledge.com/eBooks.htm

Other notes:
The SIM card can be changed to a provider account other than Amazon. In fact, Amazon will sell you a un-initialized, AT&T, SIM card for about $2.

SIM cards can hold multiple provider access point names, if my human memory serves, 16 of them. It may be possible to add access point names for accounts other than Amazon's account.
EDIT:
That last statement wasn't clear. Sorry.
The access point name(s) are read and written with modem "AT" commands. Any modem can do that, those commands are part of the ones required by the industry standards.
There is also a "locking" feature for "locking" a SIM card. The "may be possible" comes from my not being certain if the Amazon SIM card is cryptographically locked.

The AnyData modem/radio is a mini-PCIe card in the K3-keyboard. Easy to change out for another modem/radio that has different features (like the voice channel services).
Some (most?) of these use the same Qualcom (ARM) SoC and recognize nearly all of the same "AT" modem commands.

[jmseight]

Hi KNC1,

Thank you for the comprehensive listing. I am not asking about using the 3G connection but using the wifi. There is a SIP client on my son's DSi over wifi and it seems to be working.

Thanks,
James

[hawhill]

And I think this could work on the Kindle, too. It's just that nobody did a port of an SIP client yet. Well, strictly speaking, some software wouldn't even be needed to get ported. I can see no reason why e.g. a CLI client - let's say from a Debian install - wouldn't work as-is. Well, maybe the firewall settings must be fitted to this, but it should work.

However, the harder part would be to port a full GUI client since there probably isn't any existing software that is fitted to the Kindle environment in that regard.

As far as I can see, sjphone is proprietary software and would legally impossible, technically almost impossible to port.

[knc1]

Originally Posted by jmseight

Hi KNC1,

Thank you for the comprehensive listing. I am not asking about using the 3G connection but using the wifi. There is a SIP client on my son's DSi over wifi and it seems to be working.

Thanks,
James

A SIP client for what?
I only mentioned a very few of the possibilities.

Since SIP is an application level protocol, like HTTP.
Then having a "SIP client" does not help me understand what your son has working.
I am trying hard to understand your question, please help me.

@Hawhill:
sjphone does look to be closed source to me also.
But there are open source "soft phone" applications. It would take some research to decide which one(s) to try.

Also, the "reference implementation" of the SIP stack is written in Java and placed in the Public Domain by the standards organization(s).
Java <=> Lua is often easy, so a Lua-SIP stack might not be that hard to do.
(And sometimes it isn't, but why rain on anone's parade this soon?)

[geekmaster]

"With less than 150KB for complete SIP features, PJSIP is ideal not only for embedded development where space is costly but also for general applications where smaller size means shorter download time for users."

PJSIP open source SIP stack:
http://www.pjsip.org/

Building PJSIP for other platforms:
http://trac.pjsip.org/repos/wiki/Get...ther-Platforms

Discussion of porting PJSIP to arm linux:
http://comments.gmane.org/gmane.comp.voip.pjsip/12274

[geekmaster]

reSIProcate

"... dedicated to maintaining a complete, correct, and commercially usable implementation of SIP ..."
http://www.resiprocate.org/

"supports the following compilers: ... ARM cross compiler ...":
http://www.resiprocate.org/The_reSIProcate_build_system

[lrizzo]

Originally Posted by jmseight

Hi All,

I read in the forum that there are some interest in making SIP client on Kindle, like port of sjphone. Since the K3 has mic and speaker, is this feasible?

Has someone done it already?

This would be an excellent hack.

Thanks,
James

I suggest you to look at baresip http://freecode.com/projects/baresip
I successfully built and run it on the K3 when it was at version 0.1.0
The author might have integrated some of my changes.

cheers
luigi

[jmseight]

Hi All,

Please see the SIP client that is on the DSi.

http://www.ds-xtra.com/SvSIP

This works on the DSi, but I am not sure of the constraint difference between the difference devices.

Thanks,
James

[knc1]

Originally Posted by jmseight

Hi All,

Please see the SIP client that is on the DSi.

http://www.ds-xtra.com/SvSIP

SvSIP Application to use VoIP to make phone calls using your DS

That seems clear.

[thatworkshop]

Originally Posted by jmseight

Has someone done it already?

I've x-compiled pjsua for Kindle (attached, but remove txt extension), and I've made a call to my SIP number and it can pick it up, but the issue is that some parts of code need to change so that the voice IN/OUT of Kindle (drivers) can be supported in pjsip. Therefore, right now, it's of no practical use.

As you said, there was another thread about this SIP thing (in which this question could have been asked in there too!!!)... I'm worried if we continue this way, and everyone comes and creates a thread, soon MR will be a huge mess.

[knc1]

Originally Posted by lrizzo

I suggest you to look at baresip http://freecode.com/projects/baresip
I successfully built and run it on the K3 when it was at version 0.1.0
The author might have integrated some of my changes.

cheers
luigi

Only eyeballed the reading and some of the code but that does look like a good base to start a project on.

Above link is to the baresip project page.

The author also has an index page set up for the components:
http://www.creytiv.com/

@jmseight
Why don't you open a project for this?

See upper left-hand corner of page, "Dev Hub" or:
https://dev.mobileread.com/trac/hub/

And if you do, when you update that front page you get to add the very first "Kindle project" being hosted.

[toehio]

I managed to compile pjsua against alsa and make a call on the Kindle Keyboard: http://theo.cc/blog/2012/04/compile-...-the-kindle-3/

The sound support is somewhat flaky -- on some calls everything works fine, but on others either the mic or speakers don't work. Maybe this can be fixed with by changing some options to pjsua. Any advice would be appreciated.

[jmseight]

Hi cscat,

I tried pjusa and got a GLIB error - I remember GLIB 27 not found or something like that.

Hi toehio,

Would you please post the binary for this. I would like to try this out.

Hi knc1,

I have only c and C++ programming experience from 15+ years ago and am trying to learn bash and java programming - from getting the kindle.

Thanks,
James

[toehio]

Hello jmseight,

Here are the binaries I compiled. PM me if you have any problems with it.