Force the extension to able to call only predetermined extension(s)

Current setup:

sipml5 (Web browser)  <--> FreePBX 5.211.65-15 <--> Softphone

The sip_custom_post.conf contains:

[1060] ;WebRTC client
type=friend
username=1060
host=dynamic
secret=secret
encryption=yes
avpf=yes
icesupport=yes
context=default
directmedia=no
transport=ws
disallow=all
allow=ulaw
force_avp=yes
nat=no
dtlsenable=yes
dtlsverify=no
dtlsrekey=60
dtlscertfile=/etc/asterisk/keys/asterisk.pem

[1061] ;Softphone
type=friend
username=1061
host=dynamic
secret=secret
context=default
encryption=no
avpf=no
disallow=all
allow=ulaw
icesupport=yes

sipml5 has a js code to call from 1060 to 1061. Is there any configuration that the 1060 was able to call to 1061 and to that extension only? All tries to other extensions should be ignored. 1060 and 1061 are for testing only, I am planning to add the extensions through the GUI.

Regards, Kair.

The easy solution would be to purchase the Class of service module for $99.00.

@alan thank you for inputs. Found even more easier solution, define custom context and add the desired destination extension

[web-client]
exten => 1061,1,Dial(SIP/1061)

and in sip_custom_post.conf

[1060] ;WebRTC client
...
context=web-client
...

Any other attempt to call from 1060 => ! 1061 will end up ‘extension not found in context ‘web-client’’.

Everything you have put in this custom file can be configured from within the FreePBX GUI in FreePBX 12. Just FYI (Yes I know you are using 2.11)