Until recently, recording a telephone call required special hardware or software.
Hardware
Because hardware recording devices are cumbersome and expensive, they have been primarily used by law enforcement agencies. For this reason, hardware-based call recording is frequently conflated with telephone tapping.
Software
Software-based recording solutions emerged shortly after sound boards were introduced for the personal computer in the late 1980s. Software-based recording applications on mobile telephones emerged shortly after the release of the first smartphones.
VoIP
Voice over IP (VoIP) telephony began emerging in the mid 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 telco long-distance charges, either allowing callers to communicate directly, or allowing them to connect to local telco bridges. Finally, telcos themselves very quickly deployed IP-based backbones in order to more efficiently carry their long-distance traffic.
The rapid growth of VoIP-based telephony has led to the introduction of a plethora of VoIP recording solutions. All VoIP services allow or will soon allow calls to be recorded.
Recent developments
Telephony technology mashups
In recent years traditional and VoIP telephony have blended together in many combinations. Most people no longer know or care which technology they use to make a telephone call. They may use a soft VoIP phone on their computer, a traditional land line in their kitchen, and both a VoIP and a "traditional" dialer on their mobile telephone. The person at the other end of the call may be forwarding their land line to Skype, or their VoIP connection to their mobile.
Because we use so many different telephones, from so many different locations, device or location-based recording methods fall short. A lawyer needing to record conversations with clients, for example, needs to capture calls from her office telephone system, from her mobile, and from her 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.
Cloud-based services
In the late 1990s companies started selling software as a service directly over the Internet. This allowed clients to pay subscription instead of license fees, and also allowed them to forget about running the software altogether.
Although advantageous in many ways for the software vendors, they had to become experts in data center operations.
In late 2006 Amazon introduced the first public cloud computing service. It gave anyone with a credit card the ability to turn up computers on demand. Amazon managed the computers, the storage, and the bandwidth. Other vendors including Google, Rackspace, and Microsoft soon followed.
It wasn't long before telephony services began migrating into the cloud.
Cloud-based call recording services
Approaches
Cloud-based call recording services follow one of three models:
- Calling Card
- Device-based Redirect
- Cloud Bridge
The earliest services used the calling card model, making use of telephony service wholesalers. A sophisticated device-based redirect solutions appeared in the UK in 2009 to address newly introduced regulatory requirements. The first cloud-bridge service was introduced in the US in early 2011.
Vendors in this space are quickly moving towards hybrid approaches designed to meet the needs of various communities.
Calling card model
The calling card model requires a user to dial a number, input a code or key, and then dial the desired number.
In most cases, the telephony portion of the services is not itself hosted in the cloud, although the rest of the service may well be.
RecordAll is an example of a service built using this model.
Device redirect model
In 2008 the Financial Services Authority (FSA) in the UK published a policy directive requiring regulated financial services firms to record their employees mobile telephone calls. Due to industry push-back and implementation difficulties, the requirement was delayed until November 2011.
In order to meet this requirement, the mobile call recording industry explored solutions that could not be circumvented, so that all outbound and inbound calls are automatically recorded. This device redirect approach differs from more traditional device-based recording solution in that the recording is not made and stored on the handset but, rather, made and stored in a cloud-based recording system that is automatically conferenced-in with any call.
An example of a service built using this model is Red Box Recorders Quantify Mobile Recorder, VoxSmart's VoxRecord service, MobileGuard's VoiceGuard application/service. and 24 Seven Communications' service, Jump®
Cloud bridge model
Services built using the cloud bridge model place almost all of the functionality in the cloud. Calls are triggered from VoIP clients, smartphones, web browsers, and applications.
Some services, those supporting VoIP clients in particular, appear to make a direct connection to the destination telephone. Signaling the service to record the call takes place transparently.
Others services signal the service when placing a call, but do not call into it. Instead, the service calls both the source and destination numbers, bridges them, and records the call.
In all cases, the service is tightly integrated into a telephony infrastructure. Both reside in the cloud. This allows providers to store recordings in the cloud and make them available to subscribers through personal portals.
Google Voice and Call Trunk are good examples of the cloud bridge model. Google Voice requires that subscriber phone(s) 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.
Hybrids
As the industry matures we can expect to see the emergence of hybrids of these three models as vendors address the needs of both consumers and commercial verticals.