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 zaptel/dahdi wildcard (TE400P) in High Impedance mode and record through /dev/zaptel/* (Linux)
-use lates Sangoma feature called Call Tapping
-use cards for call recording from SynWay
-use a Voicetronix OpenPRI card. URMS from ConvergenceOne system use this technology.

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 A102D (2 port Sangoma) 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 :)

How to do it here:

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.

Traditional Call Logging companies

• Nice Systems - Expensive and well-known EMEA company from Israel.
• Trisys Call Recording - Call Accounting and Telephone Expense Management (TEM) solutions

New Call Logging Companies

ConvergenceOne has developed a new product URMS which offers many of the features found in traditional call recording systems at a fraction of the cost. URMS uses the Voicetronix OpenPRI cards for passive ISDN and PRI call recording and their OpenPCI cards for analogue trunk line and station recording. ConvergenceOne also offers a SIP only recorder for clients looking for SIP based call recording. In addition URMS can offer ScreenCapture on Windows, Linux and OSX platforms and integrate with SMDR/CDR from legacy/proprietary phone systems. Open Unified Recording (OUR) has been released under GPLv3. A standard SIP based solution is provided by Verba Technologies. Their Verba Recording System is tested with many Asterisk-based PBXs.

See Also

• Asterisk cmd Record
• Asterisk cmd Playback
• Asterisk cmd Read
• Database Systems Corp. - Call center software including IVR software with call recording feature. See IVR software API routines, specifically start and end recording functions.
• Unified Recording Management System - Unified Recording Management System (URMS) is a Call Recording and Screen Capture Platform.
• Verba Technologies - provides standard SIP recording solutions compliance tested with Asterisk-based PBXs.