[OpenSER-Users] Blacklisted Destinations using Database or Text File

Hello Everyone, I was using openser for some time as a proxy registrar only with excellent results, now I need to do a more complex application. The scenario is: PSTN--DS3 Connection--CISCO AS5400 ----Openser We have a Cisco AS5400 connected with a DS3 to the PSTN and need to terminate some traffic, however we need to block about 5,000 out of 120,000 possible destinations based in the first 6 digits of destination dialed. For example, destination dialed is 13054941678. First, the leading 1 is removed, then if 305494 is in blacklist some message is sent back to sender (503 Service Unavailable). If 305494 is not in blacklist the call is routed to Cisco AS5400. How do you think I can accomplish this without adding appreciable post-dial-delay and having 1 call per second? Thank you for reading my post. JP