There are three main methods for recording telephone calls
- Trunk-side call recording
- Station-side call recording
- Voice Over IP (VoIP) call recording
In the classical world of telephony, ‘TDM- Trunk-side recording’ (TDM = time division multiplex) stands for a passive connection of the communication recording system to the external trunk line of a contact centre. Since there are usually fewer external channels than internal extensions available, this connection type leads to a selection of recording channels. This connection type has two main disadvantages: first of all, internal calls cannot be recorded and secondly, CT-Integration with the PBX or the ACD system is imperative.
In the classical telephony world, the safest type of voice recording is the ‘Extension-side recording’ type. This means that the call recorder is connected in parallel to each extension station that is to be recorded. Call recorders typically provide analogue as well as digital interfaces to the leading PBXs and ACD systems.
Call recording solutions typically work in Voice over IP (VoIP) network environments, to record and replay IP-based phone calls.
Depending on the requested system configuration, the VoIP recording solution offers different ways to plug in:
Central active VoIP recording
This may be installed at any place within the IP network. It receives data by initiating an active third-party conference.
Gateway-side passive VoIP recording
The call recorder analyses data traffic at a gateway (connection to the public telephone network) or at a router (connection to another IP phone network).
Station-side passive VoIP recording
The call recorder taps network connections of each IP phone.
Also refer to our article on VoIP Call Recording
Integrated call recording systems
A number of telephone systems as well as hosted ACD systems now come with the ability for integrated call recording.
Voice recording and speech analytics are pre-integrated, for example, with NewVoiceMedia’s ACD and IVR for inbound and outbound calls.
Most independent voice recording systems need a data connection between them and each device they are recording, which is expensive to maintain and technically complex (essentially they are passing instructions to start/stop the call recording and tags to allow subsequent identification and retrieval). With cloud-based systems there is typically one interface to set up and manage call recordings across all devices and agent locations. There’s also no need to put expensive voice recording kit into each site.
This technology ensures recordings can be archived and easily retrieved, whereas multi-site recordings are usually difficult to archive and retrieve with conventional systems.
With conventional systems, getting the end-to-end experience recorded when calls are transferred between teams or sites is very complex and potentially insecure, involves special recording techniques and lots of analyst time to match calls up.