Allied Telesis AT-PBC18 - Manual (Page 80)

Installing a Switch Module
80
Switch
Performance
The performance specifications are listed below:
❑ 148,800 pps for 100 Mbps and 14,880 pps for 10 Mbps for full wire
speed forwarding and filtering
❑ 200 Mbps maximum throughput in 100 Mbps, full-duplex mode
❑ 20 Mbps maximum throughput in 10 Mbps, full-duplex mode
❑ Up to 8,192 unicast MAC addresses and unlimited
multicast/broadcast addresses
❑ 280 kilobytes (per port) packet buffer
❑ Low latency 14.3
µ
s (64-byte packet, 100 Mbps full-duplex)
Frame Processing
The PowerBlade Switch modules support store and forward switching at
Fast Ethernet full-wire speed either in 10 or 100 Mbps, half- or full-duplex
mode. Packets entering each port are stored in buffers. After the full
packet is received, it is forwarded or discarded depending on its
destination address and error status. This ensures that only error-free
data packets destined for another segment will be transferred across the
switch, reducing network load. For example, if the packet entering from
Port 1 is destined for an end station on Port 2, it will be forwarded if the
Frame Check Sequence (FCS) is valid. If the packet from Port 1 is destined
for an end station also attached to Port 1, then the packet is discarded.
The switch will discard CRC error, misaligned, runt, and under-
sized/over-sized packets. When the packet has dribble bits at the end,
the switch will truncate to octet boundary and check for a good FCS
before forwarding.
Address
Recognition and
Filtering
Up to 4,000 MAC addresses can be stored in the MAC address table in
the switch modules. The switch will learn all new addresses in real-time
after power-up with its address self-learning mechanism. If the source
address of an incoming packet is not found in the address table, the
switch updates its MAC address table. Because the switch has Automatic
Address Aging, if a source address entry in the table is not updated
within five minutes, the entry is deleted from the table. The switch
forwards all multicast, broadcast, and unicast packets when the MAC
address table size is exceeded.