This section details the new disaggregated Metro Edge Fabric, including its components and distributed control plane.

The Metro Edge Fabric is a component of Cisco Metro solution architecture that is designed to provide scalable edge services termination. The Metro Edge Fabric is designed to enhance network efficiency and scalability by separating network functions into distinct physical layers. Cisco Fabric-based Edge solution is a composition of multiple routers in a leaf-spine architecture to accommodate required functionality and scale that cannot be met in a standalone multi-service edge (MSE) model.

Edge Fabric leaf

Leaf nodes are the routers that are used for network service termination use cases. You can split the specific services across a set of leaf devices based on the design and network services. The leaf nodes may be collapsed into a universal leaf for all functions or split between different network or even VPN service type. All Cisco IOS XR platforms can be used as a leaf in the deployment depending on the feature requirements and feature scale.

Edge Fabric spine

The Edge Fabric aggregation routers or spines are the nodes that provides underlay connectivity to all leaf nodes that include service termination nodes, core networking connecting nodes, edge DC connecting nodes, and so on. These spine nodes act as L3/SR-MPLS switch that carry overlay services across leaf nodes. Spine nodes have advanced policy-based traffic management functionalities to support end-to-end QoS for selective overlay services.

Fabric interconnect

The fabric interconnects are the links connecting leaf nodes to spine nodes. Each leaf node must be connected to every spine node to provide maximum resiliency and load balancing across the fabric. It is recommended to standardize local interconnects to one type—copper (CU) or active optical cables (AOC) being the most cost-effective method. Interconnects may also utilize WAN connectivity in the case of remote leaf devices. Longer distances can be covered using Routed Optical Networking components such as ZR/ZR+, DP04QSDD-ER1, and QSFP-DD 100G ZR coherent optics.

Fabric control plane

The Fabric uses standard routing protocols; it does not use proprietary communication between the elements. This allows providers to easily insert any type of node, including third-party node, into the fabric.

The table gives a comparison of the common network technologies and protocols that are used in legacy networks vs. the Metro solution.

These are the key pillars of Metro architecture:

• Wide range of supported interfaces:

  • 1/10/25/50/100/400GE and beyond on unified family of Metro devices

  • Any speed user–network interface (UNI) with any service

  • High speed network-to-network interfaces (NNI) and Routed Optical Networking

• Simplified connectivity model and protocols:

  • Segment Routing IPv6 (SRv6) and SR-MPLS underlay networks; SRv6-TE and SR-MPLS TE for advanced Traffic Engineered use cases

  • Secured infrastructure using Trusted Cisco platforms and advanced distributed DDoS protection

  • Co-existence with legacy underlay and overlay technologies

• Business, residential, and mobile subscriber services:

  • EVPN and L3VPN in services layer

  • Private Line Emulation (PLE) for bit-transparent transport of Ethernet and non-Ethernet (OTN, SONET, Fiber Channel)

  • Next-generation subscriber edge using control plane and user plane separation (CUPS)

  • Converged business and subscriber access using Cisco Routed PON

• High performance end-to-end timing and synchronization

• Automation across all components in the architecture covering provisioning, monitoring, and service assurance