BECKHOFF CU2608 - Manual (Page 9)

Product overview
CU2608 5
Basic Function Principles
Store and Forward
The switch operates according to the store-and-forward principle. Frames that are faulty (CRC error), too short (< 64
bytes) or too long (> 1536 bytes) are not passed on in general.
Address Memory
The switch learns the MAC addresses of the connected devices for each port. Only frames that have these
addresses, broadcast/or multi-cast addresses, or which have unknown addresses are passed on to this port.
Because the switch remembers more than 1000 addresses for each port, it is also suitable for connecting entire
network segments. After approx. 5 minutes (Aging Time) unused addresses are removed from the memory – if
required, they are re-learnt again later.
Throughput
The switch can pass through up to 148800 Ethernet frames per second (Wire Speed).
PoE - Power over Ethernet
The switches CU20xx, CU22xx and CU26xx do not support the PoE acc. to IEEE 802.3, they do not indicate as a
PSE (power sourcing equipment) or PD (powered devices). Therefore, a PSE, which is connected to the switch, must
not put on voltage.
A passive transmitting or distribution is not intended in the standard
Jumbo Frames
Jumbo Frames are oversized Ethernet telegrams with a length of more than 1518 bytes. They are used in
applications that require very high data throughput, for example.
The CU2208 (from hardware version 01) supports Jumbo Frames up to 9720 bytes on all ports. Please note the
following:
•
Jumbo Frames only supported by ports with Gbit link
•
Jumbo Frames place high demands on internal data transmission. It is therefore necessary to assess the
data throughput that can be achieved through the CU2208 for each individual application. Under full load no
more than 2 ports can be used for Jumbo Frames at the same time.
Jumbo Frames are not subject to standardization. It is therefore necessary to verify that the frames used by the
application are supported by the CU2208.