OPTICAL SYSTEMS DESIGN
DOC ID: 10118101
OSD2512 OPERATOR MANUAL
PAGE 189
Port VLAN
Determines the port's VLAN ID (a.k.a. PVID). Allowed VLANs are in the range 1 through
4095, default being 1.
On ingress, frames get classified to the Port VLAN if the port is configured as VLAN
unaware, the frame is untagged, or VLAN awareness is enabled on the port, but the frame is
priority tagged (VLAN ID = 0).
On egress, frames classified to the Port VLAN do not get tagged if Egress Tagging
configuration is set to untag Port VLAN.
The Port VLAN is called an "Access VLAN" for ports in Access mode and Native VLAN for
ports in Trunk or Hybrid mode.
Port Type
Ports in hybrid mode allow for changing the port type, that is, whether a frame's VLAN tag is
used to classify the frame on ingress to a particular VLAN, and if so, which TPID it reacts on.
Likewise, on egress, the Port Type determines the TPID of the tag, if a tag is required.
Unaware:
On ingress, all frames, whether carrying a VLAN tag or not, get classified to the Port VLAN,
and possible tags are not removed on egress.
C-Port:
On ingress, frames with a VLAN tag with TPID = 0x8100 get classified to the VLAN ID
embedded in the tag.
If a frame is untagged or priority tagged, the frame gets classified to the Port VLAN.
If frames must be tagged on egress, they will be tagged with a C-tag.
S-Port:
On egress, if frames must be tagged, they will be tagged with an S-tag.
On ingress, frames with a VLAN tag with TPID = 0x88A8 get classified to the VLAN ID
embedded in the tag.
Priority-tagged frames are classified to the Port VLAN.
If the port is configured to accept
Tagged Only
frames (see Ingress Acceptance below),
frames without this TPID are dropped.
Notice:
If the S-port is configured to accept Tagged and Untagged frames (see Ingress Acceptance
below), frames with a C-tag are treated like frames with an S-tag.
If the S-port is configured to accept Untagged Only frames, S-tagged frames will be discarded
(except for priority S-tagged frames). C-tagged frames are initially considered untagged and
will therefore not be discarded. Later on in the ingress classification process, they will get
classified to the VLAN embedded in the tag instead of the port VLAN ID.
S-Custom-Port:
On egress, if frames must be tagged, they will be tagged with the custom S-tag.
On ingress, frames with a VLAN tag with a TPID equal to the Ethertype configured for
Custom-S ports get classified to the VLAN ID embedded in the tag.
Priority-tagged frames are classified to the Port VLAN.
If the port is configured to accept
Tagged Only
frames (see Ingress Acceptance below),
frames without this TPID are dropped.
Notice:
If the custom S-port is configured to accept Tagged and Untagged frames (see Ingress
Acceptance below), frames with a C-tag are treated like frames with a custom S-tag.
