Block extension to extension calling

Hi,

I have a problem with extension to extension call blocking.
Here is my scenario, I have 3 custom-groups : from-internal (default) [extension:402], from-custom-group1[extension:400 and 403], and from-custom-group2 [extension:408 and 409].

I understand that I need to create groups/custom context for each group extension which I successfully did.

In extensions_custom.conf file I wrote,

[from-custom-group1]
exten => 400,1,Macro(exten-vm,400,400)
exten => 400,n,Hangup
exten => 400,hint,SIP/400
exten => ${VM_PREFIX}400,1,Macro(vm,400,DIRECTDIAL)
exten => ${VM_PREFIX}400,n,Hangup
exten => vmb400,1,Macro(vm,400,BUSY)
exten => vmb400,n,Hangup
exten => vmu400,1,Macro(vm,400,NOANSWER)
exten => vmu400,n,Hangup
exten => vms400,1,Macro(vm,400,NOMESSAGE)
exten => vms400,n,Hangup
exten => 403,1,Macro(exten-vm,403,403)
exten => 403,n,Hangup
exten => 403,hint,SIP/403
exten => ${VM_PREFIX}403,1,Macro(vm,403,DIRECTDIAL)
exten => ${VM_PREFIX}403,n,Hangup
exten => vmb403,1,Macro(vm,403,BUSY)
exten => vmb403,n,Hangup
exten => vmu403,1,Macro(vm,403,NOANSWER)
exten => vmu403,n,Hangup
exten => vms403,1,Macro(vm,403,NOMESSAGE)
exten => vms403,n,Hangup
include => from-internal

[from-custom-group2]
exten => 408,1,Macro(exten-vm,408,408)
exten => 408,n,Hangup
exten => 408,hint,SIP/408
exten => ${VM_PREFIX}408,1,Macro(vm,408,DIRECTDIAL)
exten => ${VM_PREFIX}408,n,Hangup
exten => vmb408,1,Macro(vm,408,BUSY)
exten => vmb408,n,Hangup
exten => vmu408,1,Macro(vm,408,NOANSWER)
exten => vmu408,n,Hangup
exten => vms408,1,Macro(vm,408,NOMESSAGE)
exten => vms408,n,Hangup
exten => 409,1,Macro(exten-vm,409,409)
exten => 409,n,Hangup
exten => 409,hint,SIP/409
exten => ${VM_PREFIX}409,1,Macro(vm,409,DIRECTDIAL)
exten => ${VM_PREFIX}409,n,Hangup
exten => vmb409,1,Macro(vm,409,BUSY)
exten => vmb409,n,Hangup
exten => vmu409,1,Macro(vm,409,NOANSWER)
exten => vmu409,n,Hangup
exten => vms409,1,Macro(vm,409,NOMESSAGE)
exten => vms409,n,Hangup
include => from-internal

Extension 402(from-internal) can call any other extension in different context. My remaining problem is for 400 and 403 can call 402 BUT not 408 and 409, and vise versa.

Can anyone help me with this, I just hope that extension blocking is possible.

Thanks!

I already found the solution, just need to add extension and block by digit.