Optical Systems Design OSD2524, User Manual

Page: 188 / 402

OPTICAL SYSTEMS DESIGN
DOC ID: 10120001
OSD2524 OPERATOR MANUAL
PAGE 188
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.
If the Custom S-port is configured to accept Untagged Only frames, custom S-tagged frames will be
discarded (except for priority custom 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.