Upgrade Procedure User Manual
Page 12Biamp Systems | AVB Resource Guide
Q: What are switch manufacturers doing with AVB?
A: In order to leverage the use of AVB, the switching network is used to perform
the heavy lifting items such as trac shaping and stream reservation. In order
to do this, there is a requirement for updated features in the switch chipsets.
Many switches already have the hardware built-in and it’s simply a matter of
upgrading the software to enable the AVB feature set. Typically this is enabled
with a software license on the switch.
Q: What layers of technology are available with AVB?
A: While an IEEE working group has recently ratified an AVB transport protocol
for use at Layer 3, it currently only operates as a Layer 2 protocol.
Q: What are the product channel capacities?
A: There are variable stream sizes. Each stream can support between 1-60
channels. Hardware endpoints will dictate the local hardware input or output
channel capabilities or requirements.
Q: Are media converters available?
A: AVB bridges/switches are aware of the AVB data packets they are handling
and will provide QoS based on the data they are receiving. The switch will be
aware of AVB talkers and listeners on the network and any active streams. In
order to move AVB data around a network, bridges/switches will need to know
how to handle any AVB data. Some media converters act as bridges/switches,
which ,if not AVB capable, will not adjust the timing information appropriately
in the protocols and, therefore, will act as an AVB boundary. Other media
converters act as “true” converters and the latencies incurred are typically within
the tolerance allowed by the AVB devices. These will allow the AVB boundary to
be extended to another AVB-aware bridge/switch.
Q: How many channels can I send through AVB?
A: AVB uses the concept of streams and channels. A stream is a connection
from one talker to one or more listeners. One stream can be made up of 1-60
channels. Up to 64 streams in and 64 streams out of an (Tesira) AVB interface
are supported.
Stream Channel Count Gigabit Ethernet link utilization Total channels
7 x 60 channels (Max Bandwidth) 68.45% 420
14x 30 channels (Max Bandwidth) 71.77% 420
20x 20 channels (Max Bandwidth) 71.54% 400
32 x 12 channels (Max Bandwidth) 74.76% 384
43 x 8 channels (Max Bandwidth) 73.83% 352
64 x 4 channels (Max Streams) 69.17% 256
64 x 2 channels (Max Streams) 49.82% 128