ACD82224 Datasheet, PDF (13/77 Pages) List of Unclassifed Manufacturers – 24 Ports 10/100 Fast Ethernet Switch

Starvation Control Scheme
All frames received by the ACD82224 will be stored into a common physical frame buffer pool.
In order to make sure all ports have fair access to the network, a buffer allocation scheme
(starvation control) is used to prevent active ports from occupying all the buffers and starving off
the less active ports.
The frame buffer pool is divided into 3 portions: the reserved pool, the common pool and the
extra pool, as shown in Figure-5.1:
Figure-5.1: Buffer Partition
Extra Pool
(shared by all full duplex ports
with flow control capability)
~80%
Common Pool
(shared by all the ports)
~50%
Reserved Pool
(dedicated to each port)
The reserved pool guarantees each port will have a fair network access possibility, even under
the worst traffic congestion situation. It takes about 50% of the total buffer and is evenly
allocated to each port as its dedicated buffer slot. The dedicated slot is not shared with other
ports.
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