Valid Port Models in IEEE 802.1ad Deployments

AEF.

IEEE 802.1ad is a standard that describes Ethernet operation over a Virtual Bridged Local Area Network (VLAN). In this standard, the VLAN IDs are extended to support up to 4,096 VLANs, known as S-VLANs, which can be used for service differentiation.

The standard also defines several port models that are used to classify the ports on a switch or router, depending on their role in the VLAN tagging process. The three valid port models in an IEEE 802.1ad deployment are:

A. UNI S-port: User Network Interface Single-tag port. This is a port on the customer-facing side of the service provider network, which supports a single S-VLAN tag. The UNI S-port is used to connect customer equipment, such as routers or switches, to the service provider network.

C. NNI S-port: Network-to-Network Interface Single-tag port. This is a port on the service provider-facing side of the service provider network, which supports a single S-VLAN tag. The NNI S-port is used to interconnect service provider equipment, such as switches or routers.

E. UNI C-port: User Network Interface Customer VLAN port. This is a port on the customer-facing side of the service provider network, which supports both an S-VLAN tag and a customer VLAN tag. The UNI C-port is used to connect customer equipment that supports VLAN tagging to the service provider network.

The other options in the answer choices are:

B. NNI C-port: Network-to-Network Interface Customer VLAN port. This is not a valid port model in IEEE 802.1ad.

D. UNI T-port: User Network Interface Transparent port. This is not a valid port model in IEEE 802.1ad.

F. NNI: Network-to-Network Interface. This is not a valid port model in IEEE 802.1ad as it does not specify whether it is a C-port or an S-port.

In summary, the valid port models in an IEEE 802.1ad deployment are UNI S-port, NNI S-port, and UNI C-port.