11.3.4.2
Stream Manager
Video > Encoder # > Advanced > Stream Manager
Balancing network load
Peaks in the network load vary with encoder output. Use the Stream Manager to balance
network load. It can limit the output rate per stream sent to the transmitters. Be warned that
setting the Stream bandwidth limit to a lower value may introduce latency because peaks in
the encoder output will be buffered.
Item
Description
Stream bandwidth
limit
Range: [0...100000] kbit/s. Sets the maximum bit rate per stream
sent to the transmitters. This will serve to spread bursts but in its
turn may give rise to latency, e.g. when handling large I-frames.
You are advised to limit the outgoing bit rate per encoder to a
maximum of 15 Mbit/s. The total outgoing bit rate of all encoders
(including the Live View encoder), RTSP controlled streams, and
SAP streams, should not exceed 25 Mbit/s. See the value for the
Total tx bit rate parameter on the Measurements tab of the Status
page.
The Stream bandwidth limit mechanism is disabled when Low
latency (see below) is selected. See also the graphic in the Note on
FloodGuard.
Keep-alive interval
Range: [10 … 100000] milliseconds. The frequency for sending
keep-alive messages to the encoder.
Low latency
Raises the output bandwidth limit to allow for peaks in the network
load. To be selected if you need to keep the delay between the
input and output of images as short as possible, for improved
tracking with a dome camera for example. Selecting Low latency
disables the Stream bandwidth limit mechanism.
Note on Low Latency mode: This mode may cause packet loss in the network. In this
mode, short bursts of 100 MB data may overflow the input buffer of an Ethernet aggregation
switch. As a rule of thumb, the average load of an Ethernet port should not exceed 40% of
its maximum load (i.e. 40 MB for a 100 MB port).
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