How do we block high cost 1+ locations, i.e. Bahamas, Turks & Caicos, Antigua, etc.

[kimurai]

We were testing our outbound rules to make sure that a phone will not be able to call outside of the US from within the US. We tried this with Japan and got the expected error describing that the number belonged to a forbidden country. But when we did this again with edited configurations to match the phone number length of a place in South America, we got a different error, "503 Service Unavailable/INVITE from ..."

We expect the errors to be the same since they both are blocked from the system.
Is there a reason as to why we get that error on one instance only and not the other.

 

[mattdarnell]

System Version 18.0 Update 4(Build 965)
Hosted by 3CX

The only countries we have enabled are The US & Canada

• If we attempt to call Japan, the call is blocked by the system - "Dialed number (01181333445111) belongs to forbidden country (blocked country code = 01181)"
• But if we try to call the Bahamas, area code 242, with or without a leading 1 (i.e. 12423632560) the call is not blocked

How do we block high cost 1+ locations, i.e. Bahamas, Turks & Caicos, Antigua, etc.

Thanks!

 

[Saqqara]

if you expand us , can you untick the countries not allowed.



Check your e164 settings, as these settings are used to block calls

Created outbound rules, instead of sending the call down a sip trunk use block calls

 

[mattdarnell]

Mahalo for the response!
Do you have two Outbound Rules for each country, one rule with the leading 1 as the prefix and one rule without it?

Was hoping to be able to use the block country feature, wonder how that is supposed to work.

Here is the list:

BAHAMAS	1242​
BARBADOS	1246​
ANGUILLA	1264​
ANTIGUA & BARBUDA	1268​
BRITISH VIRGIN ISLAND	1284​
US Virgin Islands	1340​
CAYMAN ISLAND	1345​
BERMUDAS	1441​
GRENADA	1473​
TURKS & CAICOS	1649​
MONTSERRAT	1664​
SAIPAN ISLAND	1670​
GUAM	1671​
AMERICAN SAMOA	1684​
ST MARTEN	1721​
ST LUCIA	1758​
DOMINICA	1767​
ST VINCENT & GRENADINES	1784​
PUERTO RICO	1787​
DOMINICAN REP	1809​
DOMINICAN REP	1829​
DOMINICAN REP	1849​
TRINIDAD & TOBAGO	1868​
ST KITTS & NEVIS	1869​
JAMAICA	1876​
PUERTO RICO	1939​

 

[Pierre_3CX]

Hello,
What you are referring to is the NANP dial plan whereby you can dial american territories as local numbers - these won't be stopped by the Allowed country codes feature as it catches only international number formats, see also my blog post on call fraud which mentions an outbound rule configuration to block these:

Don’t be “THAT” Guy Vol.2: Call Fraud
"A note for endpoints using US providers

Third, there is a similar situation with the NANP dial plan which is largely abused in call fraud schemes to place calls towards the Caribbeans: all US providers allow placing calls towards those territories as local area codes. So, for example, you can connect to the Dominican Republic with 18091234567, which will not be checked against the Allowed Country Codes as it is interpreted as a local number. +18091234567 and 01118091234567 would, however, get blocked in case the country code is disallowed.

To cope with this, you will need to add an outbound rule, on top of all others with Prefix criterion = the list of NANP territories to block, comma-separated, and for Routes: BLOCK CALL."

 

[mattdarnell]

Mahalo, we will do that. It wasn't obvious that you can have multiple prefixes.