Layer 2 VPN Service VLAN Manipulation

A.

In a Layer 2 VPN service, an Ethernet Virtual Circuit (EVC) is used to define the service parameters for a particular VPN instance. EVC is a point-to-point connection between two Provider Edge (PE) devices, and it provides the means to connect customer sites across a service provider network.

In terms of VLAN manipulation, the default behavior of an EVC-based platform is to keep the VLAN tag of the incoming frame. This means that the VLAN tag of the frame is not modified in any way, and the frame is simply forwarded across the Layer 2 VPN service with the same VLAN tag.

Option A is the correct answer because it represents the default behavior of the EVC-based platform in a Layer 2 VPN service. Option B is incorrect because attaching two VLAN tags to the incoming frame would be a form of VLAN stacking, which is not the default behavior of an EVC-based platform. Options C and D are also incorrect because they involve removing the VLAN tag(s) from the incoming frame, which would result in the loss of VLAN information and the inability to correctly forward the frame across the Layer 2 VPN service. Option E is incorrect because it implies that the VLAN tag is set to a particular value, which is not part of the default behavior of an EVC-based platform.