Ericsson EFN324, User Manual, Page: 9 / 176

Glossary
2 Introduction to the EFN324
The EFN324 is designed for use in a Public Ethernet environment. Public
Ethernet systems require enhanced functions and characteristics, such as
increased security and reliability, when compared to with traditional Ethernet
based LAN systems.
The EFN324 is used as an Ethernet access switch in an Ethernet based fiber
access system. The EFN324 aggregates physical fiber or electrical links
directly from the End­users. It then relays End­user traffic to and from
aggregation nodes on higher levels.
The EFN works primarily as an Access Node but it may also, when required,
interact with higher levels as a Layer 2 Ethernet switch. Such interventions are
broad ranging and include, for example, the following:

Snooping information from higher level as input for packet switching
decisions.

Changing header contents.

Discarding packets.
VLAN technology (IEEE 802.1Q) plays a central role in the EFN324. VLANs
are used for enhanced security and for distinguishing different services with
different requirements for transport characteristics, like delay and jitter,
availability and so on. EFN324 also supports double VLAN Tags.
EFN324 can be used as a stand­alone node, that is, a node not managed by
an ECN, but managed directly by PEM.
Alternatively, EFN324 can be used as an embedded node, that is, a node
managed by an ECN.