[Asterisk-Users] limit the length of extensions

[Deon Rodden]

How do I limit the length of an extension? In my test IVR/Automated 
Attendant (whatever it's called), at the beginning it plays "if you know 
your parties 3 digit extension, you may enter it now) and then it gives 
a list of options. If the caller puts the 3 digit extension, it goes 
through fine, if they press 1, or 2 it goes to the selected menu option, 
but if they dial 91235551212 it dials that phone number. Which of 
course, is a big security risk.

Is there a way to limit the length of an extension for an incoming call? 
My only solution right now is to duplicate ever single extension (about 
50 of them) in a seperate context, one that does not have the _9. 
extension in it, and then make the call in menu have access to that 
context.  However, if I put a limit in the entire context of 3 digits, 
then my coworkers who's phones are in that context can only dial each 
other, not 9 and an outside number. So it has to be an incoming limit or 
something.

Another possibly creative solution would be to "SetGroup(outsidecaller) 
on the incoming line" and then just before my outbound extension put 
"SetGroup(outsidecaller) and then a CheckGroup(2)" or something like 
that.  I'd have to put another "SetGroup" in the outbound extension 
because there's no way to specify the group with the checkgroup command, 
it gets it from the setgroup statement.

Any help would be appreciated.

Thanks,
Deon



[incoming]
exten => 9543340726,1,GotoIf($[${CALLERIDNAME} = anonymous]?2:4)
exten => 9543340726,2,setcidname(Blocked)
exten => 9543340726,3,setcidnum(0000000000)
exten => 9543340726,4,Goto(companyname,beginmenu,1)

[companyname]   ; All the phones, including outbound extensions are in 
this context
exten => beginmenu,1,SetVar(CALLEDNAME=CompanyName)
exten => beginmenu,2,Wait,1
exten => beginmenu,3,Background(company-main)
exten => beginmenu,4,Background(ifyouknow)
exten => beginmenu,5,Goto(company_mainmenu,s,1)
exten => 
_9NXXNXXXXXX,1,Dial(IAX2/company-asterisk at outbound-asterisk/${EXTEN:1})
exten => 502,1,Dial(SIP/whatever1&SIP/whatever2|30|m)
...

[company_mainmenu]
exten => s,1,Background(company-nav1)
exten => 1,1,Goto(company_sales,s,1) ; Sales
exten => 2,1,Goto(companyname,502,1) ; Accounting
exten => 3,1,Goto(companyname,508,1) ; Customer Care
exten => 4,1,Goto(companyname,507,1) ; Technical Support
exten => 5,1,Goto(companyname,202,1) ; Human Resources
exten => 6,1,Goto(companyname,202,1) ; Provisioning
exten => 7,1,Goto(companyname,214,1) ; Marketing
exten => 0,1,Goto(companyname,210,1) ; Operator