Axis Communications 2 user manual Other Considerations, Bandwidth, Axis

58 Bandwidth AXIS 230

Other Considerations

•The MPEG-2 encoder chip in the AXIS 230 is designed for constant video bit rates from 1.0 - 8.0 Mbit/s. The parameter on the encoder chip that controls the video bit rate allows even lower settings, but not at constant bit rates. At low bit rates, the encoder delivers variable bit rates, and the rate is strongly affected by the selected video resolution and image information.

•The video quality level can be set from 1 (low) to 7 (high.) When using the levels 1-3, the bit rate can become variable. The total bandwidth usage is determined by the audio and video quality level and the protocol-specific contribution. Using quality levels lower than 3 may reduce bandwidth usage at the expense of image quality.

The table below shows recommended video quality levels at various resolutions:

Resolution	Unicast	Multicast
4CIF	4-7	4-6
2CIF	3-7	3-6
CIF	3-7	3-6
QCIF	3-7	3-6

•There is a limit of 3 simultaneous uploads at any one time, although the number of event types configured to upload can be greater than 3.

•If installing multiple units on the same network, the bandwidth requirements will be signifi- cantly higher.