Allied Telesis AT-TS90TR - Manual (Page 17)

AT-S6 Firmware Module for AT-TS90TR Switch
5
100BASE-TX. The packets from local Data Terminal Equipment (DTE) to
100 Mbps Fast Ethernet backbone and file server are operated in store-
and-forward manner. The traffic between the two 100BASE-TX ports are
also operated in store-and-forward manner. The 100BASE-TX store-and-
forward operates in the same manner as the 10BASE-T store-and-forward
described below, except data transfer is at 100 mbps instead of 10 mbps.
Cut-through. In a 10BASE-T cut-through system, the device starts to
forward the incoming packet while the packet is still being received on the
inbound link.
Cut-through switching requires software that can both look at the start of
the packet and determine which outbound link is to be used to forward the
packet. Cut-through does not check for Cyclic Redundancy Check (CRC)
errors before forwarding a packet.
10BASE-T Store-and-forward. Store-and-forward means that your AT-
TS90TR stores the incoming packet until it has the entire packet and then
forwards it.
Store-and-forward switching, performed at the MAC layer, not only checks
for a valid CRC before forwarding a packet, but allows your AT-TS90TR to
temporarily store packets until network resources, typically an unused
link, are available for forwarding. This allows complete error checking
until the entire packet is received correctly and limits the amount of time
between when a device requests access to the network and when it is
granted permission to transmit. Full store-and-forward switching,
therefore, ensures data integrity, thus preventing network error
conditions from being generated throughout the network.
On the other hand, in a store-and-forward system, every device in the
path from the sender of the packet to the packet’s receiver adds a small
delay due to the time spent storing the packet before forwarding it.