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AMG1202-T10B/AMG1302-T10B
Support Notes
13
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the VC gets full bandwidth. If another VCs are activated later, the bandwidth is
yield to other VCs afterward.
13. Why do we perform traffic shaping in the AMG1202-T10B
/AMG1302-T10B?
The AMG1202-T10B/AMG1302-T10B must manage traffic fairly and provide
bandwidth allocation for different sorts of applications, such as voice, video,
and data. All applications have their own natural bit rate. Large data
transactions have a fluctuating natural bit rate. The AMG1302-T10B
/AMG1202-T10B is able to support variable traffic among different virtual
connections. Certain traffic may be discarded if the virtual connection
experiences congestion. Traffic shaping defines a set of actions taken by the
AMG1302-T10B/AMG1202-T10B to avoid congestion; traffic shaping takes
measures to adapt to unpredictable fluctuations in traffic flows and other
problems among virtual connections.
14. What do the parameters (PCR, SCR, MBS) mean?
Traffic shaping parameters (
PCR, SCR, MBS
) can be set in Web Configurator.
Peak Cell Rate (PCR):
The maximum bandwidth allocated to this connection.
The VC connection throughput is limited by PCR.
Sustainable Cell Rate (SCR):
The least guaranteed bandwidth of a VC.
When there are multi-VCs on the same line, the VC throughput is guaranteed
by SCR.
Maximum Burst Size (MBS):
The amount of cells transmitted through this
VC at the Peak Cell Rate before yielding to other VCs. Total bandwidth of the
line is dedicated to single VC if there is only one VC on the line. However, as
the other VC asking the bandwidth, the MBS defines the maximum number of
cells transmitted via this VC with Peak Cell rate before yielding to other VCs.
The AMG1302-T10B /AMG1202-T10B holds the parameters for shaping the
traffic among its virtual channels. If you do not need traffic shaping, please set
SCR = 0, MBS = 0 and PCR as the maximum value according to the line rate
(for example, 2.3 Mbps line rate will result PCR as 5424 cell/sec.)
15. What do the ATM QoS Types (CBR, UBR, VBR-nRT, VBR-RT)
mean?
Constant bit rate (CBR)
: An ATM bandwidth-allocation service that requires
the user to determine a fixed bandwidth requirement at the time the connection
is set up so that the data can be sent in a steady stream. CBR service is often
used when transmitting fixed-rate uncompressed video.