Cisco Cisco MediaSense Release 9.1(1) Guia Do Desenho

Proportion (M) of recorded session hours which are converted to .mp4 and retained

.mp4 average bit rate (K) in MB/hour

o Write Rate (W) = (B * P * U) * (1 + K * M)

Notwithstanding the above calculations, there is also an absolute maximum number of recordings that Cisco MediaSense can retain, no
matter how much disk space is provisioned or how long your recordings are.  That maximum depends on the number of tags, tracks,
participants, and other metadata elements per recording, but it is generally about 16 million recording sessions.

A Cisco 3945E ISR G2 router, when running as a border element and supporting simple call flows, has a capacity of about 1000 simultaneous
calls.  In many circumstances, with multiple call movements, the capacity will be lower, in the range of 800 calls due to the additional signaling
overhead.  In addition, the capacity will further be reduced when other ISR G2 functions, such as QoS, SNMP polling, or T1 based routing are
enabled.

Some customers will therefore need to deploy multiple ISR G2 routers in order to handle the required call capacity.  A single Cisco
MediaSense cluster can handle recordings from any number of ISR G2 routers.

For Call Recording

If Call Admission Control (CAC) is enabled, Unified CM automatically estimates whether there is enough available bandwidth between the
forking device and the recording server so that media quality for either the current recording or for any other media channel along that path is
not impacted. If sufficient bandwidth does not appear to be available, then Unified CM will not record the call; however the call itself does not
get dropped. There is also no alarm raised in this scenario. The only way to determine why a call did not get recorded in this situation is to
examine its logs and CDR records.

It is important to provision enough bandwidth so that this does not happen. In calculating the requirements, the Unified CM administrator
should include enough bandwidth for 

, even though the reverse direction of each stream is not actually being

used.

Bandwidth requirements also depend on the codecs in use, and in the case of video, on the frame rate, resolution and dimensions of the
image.

For Video Playback

For video playback use cases, even though Cisco MediaSense will only be sending data and not receiving it, the endpoint does not know that
in advance, and the media connection is therefore negotiated to be bi-directional.  This could be an important consideration, since video
typically requires a large pipe, and the use of bi-directional media essentially implies that you must provision double the bandwidth that you
might have otherwise expected.

Cisco MediaSense does not connect to any CTI engines, so the CTI scalability of Unified CM is not impacted.  However, when Cisco
MediaSense uses Cisco IP Phone built-in-bridge recording, the Unified CM BHCA increases by 2 additional calls for each concurrent
recording session.

For example, if the device busy hour call rate is six (6) without recording, then the BHCA with automatic recording enabled would be 18.  To
determine device BHCA with recording enabled, use this calculation (Normal BHCA  rate + (2 * Normal BHCA rate).

For more information, go to 

, and look for "Cisco Unified CM Silent Monitoring & Recording

Overview.ppt” under SIP Trunk documents.