New Training: Service Provider Bridging Concepts

In this 9-video skill, CBT Nuggets trainer Knox Hutchinson explores how Service Providers can extend layer 2 connectivity between customer sites. Watch this new Juniper training.

Watch the full course: Service Provider Routing and Switching Specialist

This training includes:

• 9 videos

• 47 minutes of training

You’ll learn these topics in this skill:

• Introducing Service Provider Bridging (aka 802.1ad, aka Q-in-Q)

• The Problems with 802.1q

• How 802.1ad Solves SOME of Those Problems

• Frame Walk

• Key Terms for Provider Bridging

• The Challenge with Multiple Service Provider Bridging

• VLAN Translation Key Terms

• Virtual Private LAN Services (VPLS)

• Summarizing Service Provider Bridging Concepts

What is 802.1ad?

In order to implement Metro Ethernet networks, the IEEE developed 802.1ad, which is also known as both Q-in-Q and service provider bridging. An amendment to 802.1Q, which provided for the insertion of a single Virtual Local Area Network (VLAN) tag into an Ethernet frame, 802.1ad extends this by allowing multiple tags into a frame.

This lets service providers apply the architecture and protocols of 802.1Q on separate LANs as well as on bridged LANs and virtual bridged LANs. It does all this with minimal interaction between the service providers and their customers.

Under 802.1ad, the provider network double-tags data that comes from their customers. The inner tag is the customer tag and is called a C-tag, and the outer tag is the service provider tag and is called an S-tag.

802.1ad comes with a number of restrictions, such as it's only supported on Ethernet flow points (EFPs) and Trunk EFPs.