FreePBX with a CPR Call Blocker V202


This is probably a silly question, but I thought I would ask any way. I have a CPR Call Blocker V202, which I have had for years and works quite well. I recently setup FreePBX with a Grandstream box for the PSTN line. I have the Grandstream FXO port connected to the telephone port on the CPR Call Blocker V202. This works as intended but I was wondering if it would be possible to create a dial pattern on the CALL_OUT route, with the codes for programming the CPR Call Blocker V202?

For example, to block a number on this box, you’d enter **7# then the number to block on a phone. I tried doing this with 9 (to get to the outbound route), but this didn’t work. I also tried adding **7# to the route without a prefix but this also did not work.

I am going to guess that this won’t be possible but thought I would ask anyway just encase!


Unrelated to the call blocker, I recommend that you set up your Outbound Routes to not require dialing 9 (or any other prefix) for normal outgoing calls. Using a prefix causes problems with contact lists and speed dial buttons in devices, redialing from device history, click-to-call, etc. It’s also prone to human error; it’s much simpler to dial the same way as you would from a landline or mobile phone.

Though I don’t have a V202 or similar, there is an occasional need to dial special codes on a PSTN line, e.g. to change forwarding, enable or disable anonymous calling, etc. I accomplish this by setting up a code in the PBX that just gives me dial tone from the PSTN. Since it’s not possible to send ‘nothing’ on the trunk, you need to do some conversion in the FXO gateway.

For example, you might choose 000 as the code for PSTN dial tone. Your Outbound Route should accept 000 and pass it to the trunk unmodified. Then, assuming that the Dial Plan for the FXO port is the default of
change it to
{<000=> | x+}
so when you dial 000, the PBX sends 000 to the HT813, which converts it to (nothing), so you should hear dial tone and can then dial **7# (or anything else that you want).

Beware that this might be a security weakness. If you have set the FXO Dial Plan to disallow expensive destinations (as a security measure in case an attacker gets control of the PBX), then an attacker who discovers your dial tone code could bypass that filtering.

If instead you want to send the **7# over the trunk, you may be able to do that by having the Outbound Route accept those characters, setting the FXO port Use # as Dial Key to No and changing Dial Plan to
Of course, this requires that the originating device and anything else in the chain also passes those characters.

That seems like a lot of extra work to implement a feature that’s already present in FreePBX. You can add numbers to a block list on the PBX directly.

I agree with Igor. The Blacklist module in FreePBX will block inbound calls by CID number. If you can get a list of numbers from the V202, you can bulk import them into the pbx blacklist.

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