I don’t undestand why it is not possible to use an indentifier with letters in some places of freepbx.
For example in “ringgroups number”. There is no problem to make the dialplan because you can use the letters, calling to the ringgroup neither, you can make a goto to a extensions with letters. And if you need your users to call it it’s possible to make an alias or to make the “ringgroup number” just a number.
Maybe normaly doesn’t matter if the name is with letters or numbers but in some times can be interesting to be able to identifier its with letters and not numbers. And its an evolution from traditional pbx to voip pbx.
Keep in mind that certain letters have meanings… for example N, X, and Z all have meanings in pattern matching. A, B, C, and D could refer to touch tone digits generated by a phone with a 4x4 tone pad. So it probably cuts down on a lot of support issues if letters aren’t allowed in the way you suggest, although there are places they are used in the FreePBX generated dial plan.
Internally, Asterisk distinguishes between extensions and patterns by requiring an underscore before the latter (something to keep in mind if you ever want to make a Misc. Application that matches a pattern - for example you could use _1NXX5551212 and/or _NXX5551212 to match on attempts to call Directory Assistance in the North American Numbering Plan area).
One other factor is that I think a few modules in FreePBX are capable of doing operations on a range of extensions, and that would be blown out the windows if extensions were non-numeric.
Still, that doesn’t necessarily mean that it could not be allowed, but right now, it just isn’t. You’d have to ask one of the developers if there are any plans to allow it in the future, and I suppose the answer to that would depend on what would “break” if non-numeric extensions, etc. were allowed. I suspect quite a bit, but I may be wrong.
As you said there are no possibities of doubt about extensions and patterns because a pattern start with _. I don’t know about digits generated by a phone with a 4x4 tone pad.
And I don’t know what it breaks. I’m not a developer, I only administrate, but I think it would be nice to use this feature of voip and it make more easy to make an organitzation of the numeration.
In the most cases the users don’t have to call to a ringgroup or to a queue. Or in some cases I think it doesn’t break anything like in the inbound routes where you can put letters in the DID but not in the CID.
Well it is only a suggestion, but I don’t know how each module of freepbx internally works I cannot evaluate what hard would be to do it.
the real reason why it is only numbers is because it started that way from the beginning and it is a big unknown what might/would break and need fixing if we started to allow non-numeric numbers.
Probably the best example is devices (if you switch into deviceanduser mode) where it would be nice to use non-numberic, maybe a mac address or other.
It is very possible that everything would work just fine if one went modifying all the validation to allow non-numeric numbers in certain places, modify db schema where needed if integers are being used for column data, etc. The hurdle is simply the cost/benefit of doing such. It’s more likely to be considered in a 3.0+ version of FreePBX then to ever be approached in the 2.x branch.