Blocking Telemarketers with an OBi ATA

July 22, 2012
No one likes telemarketers, but if you have an OBi ATA, you can easily blacklist them based on their Caller ID. For this we'll use the ATA's excellent User Defined Digit Maps feature. User Settings >> User Defined Digit Maps: (Choose any unused Digit Map and add as many numbers as you like.)
Label: Telemarketers DigitMap: (2064560661|9052811282|8888001250)
The following may be set as the InboundCallRoute of any Service Provider, or the LINE port on the OBi110.
InboundCallRoute: {(MTelemarketers):},{ph}
Should you also wish to block anonymous callers, use:
InboundCallRoute: {(MTelemarketers)|?:},{ph}
If someone calls and their Caller ID matches a number in the Telemarketers DigitMap, the OBi will act as if you were already on a call, and your phone will not ring. If you have access to an Asterisk server or you're a customer of a VoIP provider that has a recordings feature, you can play a message instead of simply blocking the call. This example assumes 12345 is an extension on sp1 that will play an appropriate message, such as Never Gonna Give You Up by Rick Astley.
InboundCallRoute: {(MTelemarketers):sp1(12345)},{ph}
This feature of OBi ATAs is one of our favourites. Even better: if you don't route your calls via an OBi110 ATA or use its VoIP features, it can still be used as a very effective, configurable telemarketer blacklist for a POTS line. Simply plug it in to any extension and it will answer calls from any blacklisted number after the first ring.
September 10, 2015
This works great but you only have 10 entry's that are available after that it's no good. I have a OBI 200, I'm still looking for the "InboundCallRoute" setting but can't seem to find it
September 10, 2015
Actually the DigitMap is limited to 511 characters, which allows you to block about 46 numbers multiplied by 10 DigitMaps.

X_InboundCallRoute is located in Physical Interfaces >> LINE Port and each SPx Service.
May 16, 2016
Here's a guide for how to use the digit maps:

One should be able to combine numbers that share the same area code and get even more than 46/entry. I had several calls coming from 361-555-xxxx and I found OBi uses x as a wild card, so one of my rules has xxx555xxxx to block all 555 numbers from any area code.