[asterisk-dev] New SIP Channel Driver Data Access Layer

[Joshua Colp]

Hi everyone!

I know it's been a bit since the new SIP channel driver has been talked 
about on the -dev list but I'd like to change that with this email. You 
may look at the subject and go "huh? what?" so let me explain a bit. As 
many of us know there are just some fundamental aspects of a channel 
driver that have to exist, outside of other decisions being made (such 
as chosen SIP stack). Configuration and the data objects that entails is 
one of them.

In past times there has never been a real clear boundary between the 
user of the data, the data itself, and that which provides or stores the 
data. Stuff has sort of leaked and blended together all over especially 
when it comes to real time. The data access layer is one different 
approach in the new SIP channel driver to help with this. All of the 
logic (configuration file access, real time, etc) will be hidden behind 
a unified API and the consumer will be none the wiser. Any details 
specific to the logic will be isolated to its implementation and will 
not have to be maintained outside of it. This will also allow the 
implementations to easily change without having to make major 
modifications to the rest of the channel driver if need be.

Before going down the road of looking at what such an API might look 
like though I've put together what I think are the fundamental objects 
it would provide. These do *not* represent every object that will exist 
or every option. More will naturally be defined as development 
progresses and additional features and functionality are implemented.

To help track this effort I have created a wiki page at 
https://wiki.asterisk.org/wiki/display/AST/SIP+Data+Access+Layer+Objects 
which contains my stab at the fundamental objects.

This is by no means set in stone which is why I'm sending this email as 
I'd like to bring about discussion to come to a collective agreement on 
what they should be and to get some input from others.

What are YOUR thoughts?

Cheers,

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at:  www.digium.com  & www.asterisk.org