Capturing Audio and/or SIP Flow of Calls

When problems occur with calls made with Blueworx Voice Response, you may want to capture the audio and SIP messages of them. You can set up filters to do this using the bvr -c command

The .wav and .sip files generated by these filters are placed into the directory specified by the recordings_directory parameter in the [log] section of bvr.config - see Log Configuration Options

The filters work by checking either the TO or FROM header in the SIP INVITE message. If the header matches the regular expression given to the filter then the call will be recorded, otherwise no automatic recording will occur. BVR will stop checking other filters if it finds a matching filter - in other words if a call would match multiple filters it will still only make one recording.

For example, if you wanted to record all calls going to the application mapping 1001 you could use the regex '.*sips?:1001@.*' - note that as the header will have more than just the SIP address within it the .* at the start and end of the expression lets it match anything that contains the specific sip: or sips: address user.

The following parameters can be used - each option can use a minimal or verbose form:

• l/list - lists the currently existing call filters. No other parameters should be specified when listing.
• f/from <regex> - specifies that this filter checks the FROM header using the regular expression that follows it.
• t/to <regex> - specifies that this filter checks the TO header using the regular expression that follows it. Only one of f and t can be specified.
• r/remove [ALL] - Changes this from a request to add a new filter into a request to remove one or more filters. May be specified with f or t to remove a particular filter or followed by ALL to remove all call filters.
• m/mono - by default the audio produced by this command is stereo wav, with one channel recorded for inbound and the other for outbound audio. This changes the format to a single channel output by mixing the two audio streams.
• n/number <number> - By default call filters are set up to trigger for one new call then remove themselves from the system. This parameter lets you specify how many calls you want this filter to trigger on before it is removed - if set to 0 then the filter will keep triggering recordings indefinitely
• s/seconds <number> - Specifies the maximum time that BVR will record for before stopping on each call. If not specified the system default set up in the [log] section of bvr.config (max_recordings_length_seconds) will be used - see Log Configuration Options
• sm/sip_monitor - sets the filter to also save the SIP flow of the call in a separate file

Here are some sample commands:

bvr -c l lists what filters are currently in place, including how many calls they have remaining to match against before deleting themselves and the parameters that they were set up with.

bvr -c f '.*@123.123.123.123*' n 0 s 60 captures all calls from a particular IP address in stereo wav format with a maximum recording length of 60 seconds

bvr -c t '.*:123.*' n 100 mono sm captures the next 100 calls to any application starting 123 in its app mapping in mono wav format and saves the SIP flow in another file.

bvr -c r ALL removes all filters from this BVR.

Please note that when outbound calls are made from BVR to another party all call filters will still check the FROM/TO header as specified in the filter - i.e. BVR does not flip which header it is examining for outbound calls

BVR does NOT delete recordings or sip flow output put into the output directory. Please be careful with how many calls you match to avoid filling up your disc.