SDN Enhanced Ethernet VPN for Data Center Interconnect

TL;DR

This paper proposes an SDN-based architecture to enhance EVPN for data center interconnects, addressing challenges in Designated Forwarder selection and improving overall performance in multi-homed environments.

Contribution

It introduces an SDN-controlled EVPN architecture that improves DF selection fairness and stability over traditional distributed algorithms.

Findings

Improved DF selection reduces traffic imbalance.

Enhanced EVPN performance in multi-homed data centers.

SDN integration simplifies control plane management.

Abstract

Ethernet Virtual Private Network (EVPN) is an emerging technology that addresses the networking challenges presented by geo-distributed Data Centers (DCs). One of the major advantages of EVPN over legacy layer 2 VPN solutions is providing All-Active (A-A) mode of operation so that the traffic can truly be multi-homed on Provider Edge (PE) routers. However, A-A mode of operation introduces new challenges. In the case where the Customer Edge (CE) router is multi-homed to one or more PE routers, it is necessary that only one of the PE routers should forward Broadcast, Unknown unicast, and Multicast (BUM) traffic into the DC. The PE router that assumes the primary role for forwarding BUM traffic to the CE device is called the Designated Forwarder (DF). The proposed solution to select the DF in the EVPN standard is based on a distributed algorithm which has a number of drawbacks such as unfairness and intermittent behavior. In this paper, we introduce a Software-Defined Networking (SDN) based architecture for EVPN support, where the SDN controller interacts with EVPN control plane. We demonstrate how our solution mitigates existing problems for DF selection which leads to improved EVPN performance.