Dual-uCPE for High-Availability Retailer Services with Fault Toleranceand Load Balancing.

Network function virtualization (NFV) enables the emergence of universal customer premises equipment (uCPE), which hosts various net-working and computing services. uCPE supports a software-defined wide area network (SO-WAN) that provides networking services to branch or remote offices, so it has the potential to host more services than CPE and virtual CPE. However, any failure of the uCPE, which hosts all the services, used in a retailer store may result in significant losses due to unrecorded transactions or the inability to conduct trans-actions. For providing high-availability (HA) of computing and networking services with minimal downtime in the event of failures, this study proposes a dual-uCPE system for retailer services. Operating in a master-slave mode, the dual-uCPE hosts three retailer applications: point of sales (POS), network video recorder (NVR), and Wi-Fi networking. Three-tier HA networking, which includes dual-WAN connections with traffic balancing, virtual routers on dual-uCPE servers, and a Wi-Fi mesh network, is proposed. The HA performance of the dual-uCPE system is evaluated by measuring the failover and failback times under various failure scenarios. The POS and NVR failover (failback) times are found to be 9.12 (7.1) and 8.76 (6.92) seconds, respectively. Moreover, the failover (failback) times for the HA networking service are both 0 seconds following WAN connection failures, 4.42 (0.13) seconds after uCPE server failures, and 40.14 (30.02) seconds after access point (AP) failures. In other words, for all of the failure scenarios, the average downtime of the proposed dual-uCPE is in the order of seconds, rather than tens of minutes as for manual recovery.