Types of Fabric Extend Deployments

As the number of Fabric Connect networks increased, the need to connect those networks became more and more desirable. Fabric Extend solves the problem of going beyond the Ethernet Fabric Connect connections to include the following IP routed wide area network (WAN) and campus solutions:

Fabric Extend over an MPLS IP-VPN provider WAN
Fabric Extend over an MPLS Virtual Private LAN Service (VPLS) or Provider Backbone Bridging (PBB) Ethernet LAN (ELAN) provider network
Fabric Extend over an IP campus network
Fabric Extend over an MPLS Pseudo-Wire or Ethernet Virtual Private Line (E-Line) provider network

Fabric Extend over an MPLS IP-VPN Provider WAN

The most common Fabric Extend deployment is a hub and spoke topology that connects the Main office over a service provider‘s MPLS IP VPN to multiple Branch offices. The following figure illustrates how the hub device on the main site establishes virtual tunnels with all of the spoke devices in the same domain. In this scenario, the traffic flows are bidirectional: from hub-to-spoke and spoke-to-hub.

Fabric Extend over an MPLS VPLS/P2P-VPLS/E-LINE/P2P-VLAN Provider Network

Where the preceding hub and spoke deployment is over a Layer 3 MPLS IP-VPN, the following VPLS deployment is over a Layer 2 segment. This type of hub and spoke deployment extends the fabric over an MPLS Virtual Private LAN Service (VPLS) or Provider Backbone Bridging (PBB) Ethernet LAN (E-LINE) network. In this scenario, the SPB nodes are connected with a point-to-point Ethernet link.

Fabric Extend over an IP Campus Network

Some customers do not want to migrate their infrastructures to SPB immediately. They want to keep their existing IP core network and deploy SPB on the edge. In this scenario, Fabric Extend supports a fabric overlay on top of the existing campus infrastructure.

The following figure illustrates how this deployment supports any-to-any traffic with full-mesh tunnels between fabric nodes. The fabric nodes serve as campus switches, support routing into the IP infrastructure, and provide an overlay fabric that enables all fabric benefits.

Fabric Extend over an MPLS PWE3/E-Line Provider Network

The following hub and spoke deployment over an MPLS Pseudowire or Ethernet Virtual Private Line (E-Line) uses service provider VLAN tunnels. Because you can map many (VID, port/mlt list) sets to an I-SID, this gives Service Providers the flexibility to let more than one customer use the same VLAN with different I-SIDs.

The following figure illustrates how two dedicated Backbone VLAN IDs (B-VIDs) are mapped from the hub to spoke sites. Logical IS-IS interfaces translate the B-VIDs and maps them to each of the branch provider VIDs.

For a detailed configuration example showing logical interfaces using B-VID translation to two different logical VLAN IDs, see Shortest Path Bridging (802.1aq) Technical Configuration Guide.