GarrettCom CSN14 Switch User Manual


 
CS14, CSN14 Series Converter Switches Installation and User Guide (02/06)
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While other switching technologies such as "cut-through" or "express" impose
minimal frame latency, they will also permit bad frames to propagate out to the Ethernet
segments connected. The "cut-through" technique permits collision fragment frames,
which are a result of late collisions, to be forwarded to add to the network traffic. Since
there is no way to filter frames with a bad CRC (the entire frame must be present in order
for CRC to be calculated), the result of indiscriminate cut-through forwarding is greater
traffic congestion, especially at peak activity. Since collisions and bad packets are more
likely when traffic is heavy, the result of store-and-forward operation is that more
bandwidth is available for good packets when the traffic load is greatest.
To minimize the possibility of dropping frames on congested ports, each
Magnum CS14 and CSN14 Series Converter Switch dynamically allocates buffer space
from 128Kb memory pool, ensuring that heavily used ports receive very large buffer space
for packet storage. (Many other switches have their packet buffer storage space divided