Call recording
The ability to record a conversation, either system wide or by meeting some filter criteria (e.g. an extension, a called number, a calling number or a line). This can be either from the start of a call regardless, or by some kind of soft button to initiate it during a call.
Because call recording at the PBX necessarily involves inserting a relay which in turns adds latency to the audio, it is sometimes better to record the call at the end user agent. For example the popular free Express Talk Sip Softphone will record calls with a return VoIP link to a VRS Call Recording Server.
Call recording is also a feature within some IVR systems. For quality control and legal purposes, call recording can be initiated using an IVR command, particularly when the call is transferred and a two-way conversation is in progress.
Passive Call Recording
If you need to record traditional PBX with E1/T1 or BRA connection there are several ways:
- use a hub or a port-mirroring switch to copy network traffic over to a VoIP recorder appliance that will filter out and record the conversations.
- use zaptel/dahdi wildcard (TE400P) in High Impedance mode and record through /dev/zaptel/* (Linux)
- use latest Sangoma feature called Call Tapping
- use cards for call recording from SynWay
- use Stand-alone PRI E1/T1 taping box from BlueNet
- use the latest Voicetronix OpenPRI multiple (E1/T1/J1) port cards, PRI Tap boxes and open source call recording software, VTlogger. For recording calls carried over POTS just use their OpenPCI Quad or Octal port cards.
Note: to 'Tap' an interface you need to record both legs, TX from Telco side and TX from PBX side, so you need AT LEAST two times more port capacity. Example: you have one E1 connection, you need at least an A102D (2 port Sangoma), or OpenPRI Dual (from Voicetronix) or TE200p (Two port Digium Card). Why is that? There are two streams with 2Mbit/s (or 1.5 Mbit/s) and you need to log both of them so you need to Receive on two ports of your Tapping card :)
Note: Big Telco vendors like Alcatel-Lucent or Avaya have a Dedicated Recording Link interface where you got E1 link with Mixed RX/TX for recording, so you need only one port (one RX Chip). You also say "put conversation between internal number 200 and outside number 1-901 234 567 on the 3rd time slot on E1 link" with CSTA and PBX does put call on this link. Good way to record calls from dect phones inside of company.
Call Recording Companies
- Voicebooth provide call recording facilities for SIP Trunks and Hosted PBX systems for both Asterisk and Freeswitch.
- DB Streams - A Canadian Company. Offering Integrated and Customized Telecommunication Solutions including ERP, CRM, Call Recording (VoIP, ISDN/PRI, Analog), IVR, Call Accounting, and Text Messaging.
- Nice Systems - Expensive and well-known EMEA company from Israel.
- SIPfish - Offers a passive VoIP-Recorder appliance with a built-in web interface. Call information is kept in a searchable database. ...