Ericsson EFN324, User Manual, Page: 38 / 176

IndexIndex
In each switching domain, one of the ports can be designated as the ‘uplink’.
Once an uplink is defined, all packets originating from other ports are
automatically forwarded to the uplink. Packets originating from the uplink are
forwarded in the same way as before. In this way, ‘uplink’ functions as one of
many mechanisms supporting forced forwarding in single EFN324 nodes.
An uplink may also be used when two or more EFN324 Ethernet access
switches form a daisy chain. The ports connecting to the overlying EFN324 are
designated as ‘uplink’. A port that connects to an underlying EFN324 is
designated as ‘transit link’.
Figure 17 Daisy Chained EFN324
When transit links are defined, the switching domain switching rules are
slightly modified. When no ordinary port is found to which to forward a packet
that originates from an uplink, by default the packet is forwarded to the transit
link. The EFN assumes if the packet destination is not found, that the receiver
is located at a switch further down in the chain.
Packets originating from a transit link are forwarded to the uplink. An uplink
should be defined whenever a transit link is defined. The switching might
however still work, even if no uplink is defined.
uplinks
transit link
EFN324 EFN324
To higher level
aggregation
Ports
Switching
domain B
uplink transit link