recording, calls are configured to always be recorded.
Communication Manager controlled 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 Communications Manager. Each line can also be configured as either
Network-Based Recording (NBR) preferred or Built-in-Bridge (BiB) recording
For Unified Border
Element dial peer recording, all calls passing through the Unified Border
Element 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 in
Incoming Call Handling Rules).
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 applications.
forking, where basically the phone or Unified Border Element 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 Unified Border Element, the Unified
Border Element device sends a SIP invitation to the recording server and the
recording server prepares to receive a pair of RTP streams from the Unified
Border Element. Finally, under NBR, Communication Manager sends a pair of SIP
invites to the recording server, and a special message to Unified Border
Element, and a pair of RTP streams from the Unified Border Element to the
This procedure has
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
end up on the same MediaSense recording server.
Most Cisco IP phones
support media forking. The IP phones that 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 that is not supported by MediaSense, the call will not be recorded. The
same is true for Unified Border Element recordings.
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 Unified Border Element, Unified
Communications Manager, and MediaSense load; as well as by network performance
characteristics along the signaling link between Unified Border Element or
Unified Communications Manager and MediaSense. MediaSense carefully monitors
this latency and raises alarms if it exceeds certain thresholds.
not initiate compliance recording. It only receives SIP invitations from
Unified Communications Manager or Unified Border Element and is not involved in
deciding which calls do or do not get recorded. The IP phone configuration and
the Unified Border Element dial peer configuration determine whether media
should be recorded. In some cases, calls may be recorded more than once, with
neither Unified Border Element, Unified Communications Manager, nor MediaSense
being aware that it is happening.
The above scenario
might occur if all contact center agent IP phones are configured for recording
and one agent calls another agent. It might also occur if a call passes through
a Unified Border Element dial peer that is configured for recording and lands
at a phone that is also configured for recording. The Unified Border Element
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 under Unified Communications Manager control,
either by BiB or NBR. Unified Border Element dial peer recording can be
configured to fork both audio and video, or to fork only the audio tracks in a
video call. Videos can also be recorded using the Direct Inbound or Outbound
mechanisms of MediaSense.
record calls of up to eight hours in duration.