asterisk users - Mar 2005 - [OT] stupid firmware question...

I know this is a really stupid question, but I just have to ask...

Where would I start if I wanted to try and develop my own firmware for a 
particular phone.  Namely, I want to try and 're-write' the SIP firmware
for Cisco 7940's.  Any ideas?

-Chris

PS: [* put on flame suit *] why won't any of the phone manufacturer's 
just open-source the firmware for their phones? [* ducks head back 
inside gopher hole just before a giant fireball hits *]

On Wed, 2005-03-02 at 14:24 -0600, Chris Wade wrote:
> I know this is a really stupid question, but I just have to ask...
> 
> Where would I start if I wanted to try and develop my own firmware for a 
> particular phone.  Namely, I want to try and 're-write' the SIP
firmware
> for Cisco 7940's.  Any ideas?
> 
> -Chris
> 
> PS: [* put on flame suit *] why won't any of the phone
manufacturer's
> just open-source the firmware for their phones? [* ducks head back 
> inside gopher hole just before a giant fireball hits *]
> 
Simple, it is likely that they put the code for the codecs in the
firmware. They have to ensure you pay your patent license fees. Granted
it is easy enough to get around once you have a firmware image for the
ciscos, but it doesn't let them off the hook on how they must guard the
code. If Cisco didn't have access to G729, most people would laugh at
their offerings and quickly jump to another product.

If you where going to rewrite the firmware, you should try and make an
IAX2 firmware for it. In fact, you should try and contact Cisco and see
if you could partner with them to write the code for an IAX2 firmware
and get help from them. They would be able to incorporate the codecs
they have licenses for and charge money for the product. Might be
interesting. 
-- 
Steven Critchfield <critch@basesys.com>

On Wed, Mar 02, 2005 at 02:24:17PM -0600, Chris Wade
wrote:
> PS: [* put on flame suit *] why won't any of the phone
manufacturer's
> just open-source the firmware for their phones? [* ducks head back 
> inside gopher hole just before a giant fireball hits *]
Probably because they're afraid you might do a better job...

That aside, if they'd acquired licences for codecs or things, it might
be tricky. Then again, if you paid for the licence when you bought the
phone why would they care.

-- 
Martijn van Oosterhout
Ecomtel Pty Ltd

On 2 Mar 2005, at 20:24, Chris Wade wrote:
> I know this is a really stupid question, but I just have to ask...
>
> Where would I start if I wanted to try and develop my own firmware for 
> a particular phone.  Namely, I want to try and 're-write' the SIP 
> firmware for Cisco 7940's.  Any ideas?
>
> -Chris
>
> PS: [* put on flame suit *] why won't any of the phone
manufacturer's
> just open-source the firmware for their phones? [* ducks head back 
> inside gopher hole just before a giant fireball hits *]
Snom do. At least there is this link on their website....

http://www.snom.com/snom_source.html?&L=1

I've not used the source as yet, but  it was one of the factors that
persuaded me to buy phones from them.


Tim.
http://www.westhawk.co.uk/