Ericsson EFN324, User Manual, Page: 37 / 176

Glossary
A normal outcome is that the packet is forwarded to one and only one of the
egress connections of the switching domain. The outcome might also be that
the packet is not forwarded to any egress connection, that is, the packet is
discarded. The packet may also be forwarded to more than one egress
connection. This is normal for multicast, but may also occur also for unicast
and broadcast.
The method used for the VLAN switching is determined by the switching rule
configured for the switching domain. Switching rules are described in section
5.3.2 on page 35. First, however, topology concepts, including ‘uplink’, are
introduced in section 5.3.1. These concepts are required to understand the
switching rules, which include forced forwarding.
This description of switching domain switching refers primarily to unicast
packets. Multicast and broadcast are described in sections 5.3.3 on page 36
and 5.3.4 on page 37.
5.3.1 Internal Topology
When a packet is switched through a switching domain, connections to at least
two separate ports must be defined: a connection from an ingress port and a
connection to an egress port. A packet cannot be forwarded to the same port
from which it arrived.
Every switching domain which carries traffic must be connected to a subset of
the 26 available Ethernet link ports. Management traffic must be connected to
the host port. A single port may be connected to more than one switching
domain, as illustrated in the following figure.
Figure 16 Port – Switching Domain Connections
Each switching domain works as a separate switch for its connected ports.
That is, when a packet arrives from a port at a switching domain, the switching
domain will select one of its other connected ports and forward the packet to
that port.
Ports
Switching
domain B Switching
domain R