Ditto VR Resources
SIPREC (SIP RECording) is a protocol that defines how SIP calls are remotely recorded and is considered to be an active recording mechanism. A SIP Recording Client (SRC) initialises the recording with a SIP Recording Server (SRS) and negotiates how the call will be setup and recorded. SIPREC works on the basis of a copy (or forked) version of the original call that is channelled to the SIPREC recording server. The SIP signalling is very similar to that of a normal call but with modified SDP and additional XML Metadata controlling what channels are or not recorded etc. The SIPREC standard is set as RFC 7865 but across the industry differing implementations have made interoperability misaligned, although this situation has improved over recent years. SIPREC is idea for cloud-based recording and disaster recovery where calls are required to be stored off-site.
The Port-Mirroring recording method passively listens to SIP traffic through a dedicated port on a network switch normally called a SPAN destination port. SPAN source port(s) are configured on the switch to copy packets from one switch port to another. The VoIP recorder monitors the calls and captures the IP packets. This technology requires the IP-PBX and recording components to be physically located to each other and so this this deployment is commonly seen in on-premise topologies.