OPERATIONAL LESSONS FROM IPV6 DEPLOYMENT IN LARGE SCALE ISP BACKBONE NETWORKS

This paper presents comprehensive operational insights from deploying IPv6 across six commercial ISPbackbone networks in sub-Saharan Africa, collectively serving more than 44.8 million subscribers. Over an18-month period, we conducted systematic measurements to evaluate real-world performance anddeployment challenges under dual-stack operation. Our analysis covers throughput, latency, packet loss,and routing convergence across diverse backbone and access environments. Results show that IPv6delivers performance comparable to IPv4, with a modest 4–6 percent TCP throughput reduction and slightUDP gains at high bitrates. Beyond performance, we identify key operational barriers including CPEcompatibility gaps, DNS and DNSSEC integration issues, and network management upgrades. We provideactionable recommendations for IPv6 planning, capacity engineering, and transition strategy selection,demonstrating that IPv6 deployment at ISP scale is both feasible and sustainable.