About Virtual Connection Access (VCAs)

VCA is used to connect one or more virtual connection endpoints (VCE) together to complete the description of the end-to-end connectivity between two ports on an Accedian Edge Element, and describes a customer's traffic flow access to the service provider's network through the performance element.

A VCA element is formed by an ordered list of one or more individual Virtual Connection Endpoints (VCE) elements in order to form an external port-to-external port definition for the Virtual Connection Access. The Virtual Connection defines the traffic path to be used by UP MEP, DOWN MEP and MIP.

The connectivity is defined from the direction of the TP-A to TP-Z endpoints on one or more VCE elements. The end-to-end connectivity from TP-Z to TP-A is automatically inferred and symmetric with end-to-end definition of TP-A to TP-Z, as shown below.

CFM Using Model

Depending on the use case, a VCE element has a type attribute: Customer (C-VLAN), Operator
(S-VLAN) or Tunnel (T-VLAN):

• A Customer VCE is used to handle customer (tagged or untagged) traffic (usually at UNI and at VUNI).
• An Operator VCE is used to tag the data frames in the operator's network.
• A Tunnel VCE is used for trunking use cases (Access Provider).

The VCE type is used to determine how to construct the bridge component and component ID required for CFM.

A Termination Point (TP) is a logical point of attachment to either a Physical (or LAG) port, referred to as an external TP, or to another VCE, referred to as an internal TP.