# Call-recording services

A call recording service is a commercial enterprise that can record telephone calls for a fee.
For example, a lawyer needing to record conversations with clients, for example, must be able to capture calls from an office telephone system, from a mobile phone, and a home line. Traditionally, this required three recording systems, one PBX-based, one smartphone-based, and one PC-based. These recordings, of course, end up in three different places. Managing this complexity is difficult, expensive, and inefficient. A service approach instead records calls over all three devices and provide convenient access to all recordings.

## History

Until recently, recording a telephone call required special hardware or software. The introduction of Alphabet Google's Android 9 Pie made call recording prohibitively difficult without rooting the phone.

### Hardware

Hardware recording devices are cumbersome and expensive, limiting their use to law enforcement agencies. For this reason, hardware-based is frequently conflated with telephone tapping. In the era of mobile telephony, services that require a device to be in a specific location have little use.

### Software

Software-based recording solutions emerged shortly after soundboards were introduced for the personal computer in the late 1980s and on mobile telephones after the release of the first smartphones.

### VoIP

Voice over IP (VoIP) telephony began emerging in the 1990s. In commercial environments VoIP was first used behind corporate PBXes in order to deploy telephones capable of delivering additional computing services. In the consumer environment, VoIP was introduced to allow people to bypass long-distance charges, either allowing callers to communicate directly, or allowing them to connect to local bridges. Telcos deployed IP-based backbones later in order to more efficiently carry long-distance traffic.
The rapid growth of VoIP-based telephony led to the introduction of a plethora of VoIP recording solutions.

## Service approaches

Call recording services follow one of three models: calling card, device-based redirect or cloud bridge.
Vendors are quickly moving towards hybrid approaches designed to meet the needs of various communities.

### Calling card

The earliest services used the calling card model, making use of telephony service wholesalers. The caller dials a central number, enters a code or key, and then dial the desired number. The service connects the call and records the interaction. RecordAll is an example of a service built using this model.

### Device redirect

The device redirect approach automatically conferences in the recording service into every call.
In 2008 the Financial Services Authority (FSA) in the United Kingdom required regulated financial services firms to record their employees' mobile calls. Due to industry push-back and implementation difficulties, the requirement was delayed until November 2011.

### Cloud bridge model

The first cloud-bridge service was introduced in the US in early 2011.
Such services place almost all of the functionality in the cloud, a remote service that stores recordings outside customer premises and makes recordings available over the internet. Calls come from VoIP clients, smartphones, web browsers and applications.
Some services, in particular those supporting VoIP clients, appear to make a direct connection to the destination telephone. Signaling the service to record the call takes place transparently.
Others approaches signal the service to place a call, but do not call into it. Instead, the service calls both the source and destination numbers, bridges them and records the conversation.
Google Voice and Call Trunk are examples. Google Voice requires that subscriber phones be registered with the service, whereas Call Trunk allows any phone to be used at any time. Google Voice allows inbound call recording only; Call Trunk only allows outbound call recording.

### Service list

| Service | Vendor | Model | Supported Source Handsets | Call/Recording Trigger |
| Call Trunk | Call Trunk Holdings Ltd. | Cloud Bridge | All | iOS, Android, BlackBerry, Web applications |
| Google Voice | Google Inc. | Cloud Bridge | All Google Voice enabled | iOS, Android, BlackBerry, Web applications |
| Primal CRS | Primal Technologies Inc. | NFV AWS, VMWare, Openstack, Scale Computing | All - iOS, Android, Legacy phones | SIP Call events |
| Viirtue VoIP | Viirtue, LLC | Viirtue VoIP Platform | All | iOS, Android, Web Applications, SIP Phones, SIP Call Events |
| Dubber | Dubber | Cloud Bridge | All | All - includes iOS, Android, SIP Call events, SIPREC, VoIP, PSTN, PBX |