GE T1000 Technical Manual page 186

GE Reason Switches
186
Mode: indicates the mode of port operation. This field will define
o
fundamental behaviour of the por. Allowed values are as follows:
Access: indicates that port will operate as an access port.

This is normally used by end stations, that is, VLAN-
unaware equipment. Main characteristics of these ports
are:

VLAN Identifier Ingress process: untagged
frames are forwarded to the Port VLAN identifier
VLAN, and tagged frames are forwarded to the
VLAN that is embedded at the frame;

Filtering ingress process: both tagged and
untagged frames are accepted, but frames that
do not belong to the Allowed Access VLANs field
or belong to the Forbidden VLANs field are
discarded;

Egress process: all frames will have its VLAN
identifier removed, that is, access ports only
egress untagged frames.
 Trunk: indicates that port will operate as a Trunk port. This
is normally used by bridges connection or IED equipment
that receives frames from multiple VLAN at the same port.
For instance, Merging Unit sending Sampled Values and
GOOSE messages throughout the same Ethernet interface
should be connected to a Trunk port, as it will receive both
VLAN messages. Main characteristics of these ports are:

VLAN Identifier Ingress process: untagged
frames are forwarded to the Port VLAN identifier
VLAN, and tagged frames are forwarded to the
VLAN that is embedded at the frame;

Filtering ingress process: ingress process
filtering will depend on the Egress tagging field
configuration. A trunk port can accept both
tagged and untagged frames if Egress tagging is
set to Untag only frames with Port VLAN
identifier. In this case, frames that do not belong
to the Allowed VLANs field or belong to the
Forbidden VLANs field are discarded. A trunk port
can accept only tagged frames if Egress tagging
is set to Tag all frames at the egressing process.
In this case, frames that do not belong to the
Allowed VLANs field or belong to the Forbidden
VLANs field are discarded;

Egress process: egress behaviour will depend on
the Egress Tagging field configuration. A Trunk
port can be set to Untag only frames with Port
VLAN identifier (that is, untagged frames leave
Chapter 7 – Configuration
REASON SWITCHES-TM-EN-3