We do this using two different tables and two different kinds of checks in the SER.cfg Keep in mind, this code is all SER 0.9.6 specific. There may be easier ways to do this in SER 2.0 For the sake of making things less messy (the idea of storing EVERY check in one usr_preferences table for ALL functions in SER is an ugly use of the database), we have a callblock table that stores per-user blocked numbers via the web interface or a phone keypad entry scheme. It has the same format as the usr_preferences table: +-----------+--------------+------+-----+-------------------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+--------------+------+-----+-------------------+-------+ | uuid | varchar(64) | NO | | | | | username | varchar(100) | NO | | 0 | | | domain | varchar(128) | NO | | | | | attribute | varchar(32) | NO | | | | | value | varchar(128) | NO | | | | | type | int(11) | NO | | 0 | | | modified | timestamp | NO | | CURRENT_TIMESTAMP | | +-----------+--------------+------+-----+-------------------+-------+ Into the attribute column goes the attribute 'callblock' and into the value goes the URI you wish to block. Then, in the code, some sort of check like: if(avp_db_load("$ruri/username","s:callblock/callblock") ) { if(avp_check("s:callblock","eq/$from/gi")) { log(1, "CallblkVM\n"); sl_send_reply("603", "Call denied"); break; }; }; For blocking ALL numbers instead of a per-user numbering scheme, we another separate table that looks like usr_preferences; however, an entry for that table might look like: insert into blocked_numbers(username,domain,attribute,value,modified) values('6667778888','local.domain','block','Blocked',now()); This stores the number to block as the username instead of as a URI int he value column. This makes the check in the SER.cfg code a little easier: if(avp_db_load("$to/username", "s:block/blocked_numbers")) { sl_send_reply("603", "Number is blocked"); break; }; Place that near the top of your invite block and all calls to 666 777 8888 from ANY user will be blocked. N. Jai Rangi wrote: