User's Manual

ALFOplus 24GHz (North America) - Release 01.05.0x - MN.00395.E - 004 37
With LLF enabled the equipment connected (routers, switches so on) can be notified that radio link is not
available and can temporarily re-route the traffic.
In same cases, the radio link failure can be unidirectional, for example when the local equipment has an
Rx signal failure but the remote Rx signal is OK (i.e. unidirectional radio full due to failure of a transmitter).
However, also in these cases there can be the need to shutdown the link in both directions even if there is
only a unidirectional link failure.
Using the bidirectional LLF feature, in case of LLF in the local equipment, the local equipment can notify
this LLF status to the remote equipment, shutting down the link on both directions.
Below it is reported an example of bidirectional LLF configuration (see Fig.8
).
Fig.8 - Bidirectional LLF
MDI/MDIX cross-over
For each LAN interface, cross-over cable can be set in Web Lct - Baseband - Lan - Cable Crossover as:
• Auto - Lan recognizes automatically the connected cable type (Straight cable or Crossover cable)
• MDI (NIC) - Manual crossover wiring type T568A
• MDI-X (Switch) - Manual crossover wiring type T568B
With crossover cable it is necessary to use the same wiring format (MDI/MDI or MDI-x/MDI-x) on both
ends. In case of straight cable is the opposite (MDI/MDI-X or MDI-X/MDI).
VLAN functionality
ALFOplus works with IEEE 802.1q and 802.1p tag. Tag is made up with:
• a fixed word of 2 bytes
• 3 bits for priority according with 802.1p
• 1 fixed bit
• 12 bits VLAN identifier (VLAN ID) according with 802.1q.
Switch cross-connections are based on Vlan Configuration Table where input and output ports or only out-
put ports should be defined for any used VID. Vlan ID (VID) has a range from 1 to 4095.
Ethernet Flow Control (802.3x)
A network device asks its adjacent devices to send a pause frame because the input is faster it can process.
The protocol used for this purpose is the flow control (802.3x).
Port Based VLan
Port Based VLan (or Lan Per Port) allows to share the Ethernet traffic (Ingress or Egress) in the internal
SIAE switch.