CANOGA PERKINS 9145ELB NID Software Version 4.01 - Manual (Page 116)

9145ELB NID Software User’s Manual Configuring EVC
EVC Functionality
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• An EVC record can contain only C-VLANs from a single User Port. EVC records do not
span across User Ports.
• A C-VLAN can belong to only one EVC record per port.
• The S-VLAN of the EVC record is unique across the system.
A VLAN multiplexing record is operationally up if:
• The corresponding User Port is operationally up. A User Port is operationally up if both
transmit and receive functions of the port are operationally up, and
• The corresponding Network Port is operationally up, and
• The VLAN multiplexing record contains at least one C-VLAN (if Service Multiplexing
type), and
• The VLAN multiplexing record is administratively up.
Frames received on an operationally down VLAN multiplexing record are dropped, and counted
per port.
10.1.2 User-to-Network Functionality
On the User Ports, the system accepts all Ethernet framing formats supported by 802.1ad-2005
standard. Frames are classified as:
• Priority tagged frames (Ethertype 0x8100, VID 0)
• C-Tagged frames (Ethertype 0x8100, VID != 0)
• Untagged frames that are neither priority tagged nor C-Tagged. Hence S-tagged frames
and all other types of tagging are treated as untagged frames on the User side port.
Based on the frame tagging and EVC records configured on the ingress port, the frame is
forwarded to the Network Port, tagged with a specific S-Tag as an outer tag.
If there is no corresponding EVC record for the ingress C-Tag, the frame is dropped.
10.1.3 Network-to-User Functionality
On the Network Port, the system accepts S-Tagged frames, namely frames tagged with
Ethertype 0x88a8 and a non-zero VID. Untagged frames are accepted, for example, PDUs for a
low-level untagged MEP, or control protocol frames.
If there is an EVC record corresponding to the ingress S-Tag, the frame is forwarded to the User
Port indicated by the record, and stripped of the S-Tag. If no EVC record is found, the frame is
dropped. If the EVC record has the tunnel tagging option enabled, the T-Tag value received in the
frame is compared to the configured value in the EVC record. If it is not a match, the frame is
dropped.
10.1.4 Statistics
An EVC record keeps statistics, as follows:
For an All-to-One Bundling EVC record, the following counters are kept:
• Number of transmitted frames and bytes at the User Port
• Number of received frames and bytes at User Port