GE QS24 UR - Manual (Page 37)

QUICKSTART GUIDE
UR SWITCH MODULE – QUICKSTART GUIDE QS–33
QS.5 Tagged VLAN’s
VLAN is short for virtual LAN. A VLAN creates separate network segments that can span
multiple switches. A VLAN is a group of ports designated by the switch as belonging to the
same broadcast domain. VLANs provide the capability of having multiple networks co-
existing on the same switch. Separation of traffic and security are just two advantages of
VLANs.
VLANs can be port-based or tag-based. Port VLANs set a specific port or group of ports to
belong to a VLAN. When using tag-based VLANs, a tag - a "VLAN identifier" - is sent as part
of the message. This tag allows the message to move across multiple switches whose
ports are part of the same tagged VLAN. Note that the UR Port (Port 7), being the port
connected to the UR relay, must therefore be included in all VLANs from which the relay is
to receive or transmit data.
Background
The IEC 61850 Fixed GOOSE peer-to-peer communication service is an enhanced version
of IEC GSSE peer-to-peer service with the additional ability to assign a priority and a "tag"
to the multi-cast messages.