In compliance recording, calls are configured to always be recorded.
For IP phone recording, all calls received by or initiated by designated phones are recorded.
Individual lines on individual phones are enabled for recording by
configuring them with an appropriate recording profile in Unified
For CUBE recording, all calls passing
through the CUBE that match particular dial peers (typically
selected by dialed number pattern) are recorded. MediaSense
itself does not control which calls are recorded (except to the limited extent described under Incoming call
recording differs from selective recording because in selective recording, the recording server determines
which calls it will record. MediaSense itself does not
support selective recording, but the effect can be achieved by
deploying MediaSense in combination with certain partner
Recording is accomplished by media forking, where basically the phone or CUBE sends a copy of the incoming and outgoing media streams
to the MediaSense recording server. When a call originates or
terminates at a recording-enabled phone, Unified Communications Manager sends a pair of
SIP invitations to both the phone and the recording server. The
recording server prepares to receive a pair of real-time
transport protocol (RTP) streams from the phone. Similarly, when a
call passes through a recording-enabled CUBE, the CUBE device sends
a SIP invitation to the recording server and the recording server prepares to receive a pair of RTP streams from the CUBE.
This procedure has several implications:
- Each recording session consists of two media streams (one for media flowing in each direction). These two streams are captured
separately on the recorder, though both streams (or tracks) end up on the same MediaSense recording server.
- Most, but not all, Cisco IP phones support media forking. Those which do not support media forking cannot
be used for phone-based recording.
- Though the phones can fork copies of media, they cannot
transcode. This means that whatever codec is negotiated by the
phone during its initial call setup, is the codec used in
recording. MediaSense supports a limited set of codecs; if
the phone negotiates a codec which is not supported by MediaSense, the call will not be recorded. The same is true for
- The recording streams are set up only after the
phone's primary conversation is fully established, which could take
some time to complete. Therefore, there is a possibility of clipping
at the beginning of each call. Clipping is typically limited to
less than two seconds, but it can be affected by overall
CUBE, Unified Communications Manager, and MediaSense load; as well as by network
performance characteristics along the signaling link between CUBE
or Unified Communications Manager and MediaSense. MediaSense carefully
monitors this latency and raises alarms if it exceeds certain
MediaSense does not initiate
compliance recording. It only receives SIP invitations from Unified Communications Manager
or CUBE and is not involved in deciding which calls do or do not get recorded. The IP phone configuration and the CUBE
dial peer configuration determine whether media should be recorded. In some cases, calls may be recorded more than once, with
neither CUBE, Unified Communications Manager, nor MediaSense being aware that it is happening.
This would be the case if, for example,
all contact center agent IP phones are configured for recording
and one agent calls another agent. It might also happen if a call
passes through a CUBE which is configured for recording and lands
at a phone which is also configured for recording. The CUBE could end up creating two recordings of its own. However, MediaSense stores enough
metadata that a client can invoke a query to locate duplicate
calls and selectively delete the extra copy.
At this time, only audio streams can be forked by Cisco IP
phones and CUBE. Compliance recording of video media
is not supported; it is only available for the blogging modes of
recording. CUBE is capable of forking the audio streams of a
video call and MediaSense can record those, but
video-enabled Cisco IP phones do not offer this capability.
MediaSense can record calls of up to eight hours in