QUESTION Order of outbound routes

[mike_h]

What is the point of having the outbound routes ordered in a specific sequence?
If I#m not mistaken, Asterisk take all patterns in the appropriate context and sorts them according to a set of rules (https://wiki.asterisk.org/wiki/display/AST/Pattern+Matching).
So, what difference does the sequence in which I ordered the outbound rules make?

 

[rossiv]

Outbound routes are used in priority from top to bottom, as sorted in FreePBX. Whichever route matches the dialed digits sent from the extension is used first. This is why emergency and extension priority routes (restricting extensions to certain trunks by ext. num.) should always be at the top.

Pattern Matching has to do with the patterns within the outbound routes, but not directly for the sorting/priority. From the wiki, I read it as the standard NXXNXXXXXX that is used to substitute for digits. Instead of typing 200-0001 to 998-9999, you do NXXNXXXXXX and it pulls every number in that pattern. If I have an outbound route at the very top that has dial rules NXXNXXXXXX and is set to TrunkA, any call placed from an extension that matches that format (ex. 8435454545) will go out that trunk.

Does that make more sense?

 

[briankelly63]

The order can be very important when trying to add logic to the call processing. Some examples are obvious but some work in reverse which can get very ingenious. It's not JUST the order its the kind of MATCH you are making with the rule. Is the route ultimately taken because of a MATCH or a non-MATCH which is effectively provided by the order.

Some routing requires scripting and could even query a database but most needs can be met with this simple scheme that doesn't require any code.

 

[mike_h]

I understand quite well why FreePBX needs to evaluate the routes in the right sequence. My problem was that I didn't understand how is does this. The described behaviour of Asterisk seemed to make this impossible.

If I#m not mistaken, Asterisk take all patterns in the appropriate context and sorts them according to a set of rules.

Here was my problem. Being a programmer, I assumed that the include works like like e.g. in C: Include all referenced include files and then parse the complete resulting file. In fact Asterisk does something a bit more complex here:

1. Take the patterns in the context without the includes and sort them according to the rules that were described in the link from the first post.
2. If that doesn't produce a match, parse the first included context.
3. If there still is no match, continue with the next included context and so on.

Thus everything works exactly as expected.