--- service: d.root-servers.net start-period: '2015-12-31T00:00:00Z' end-period: '2015-12-31T23:59:59Z' metric: traffic-volume dns-udp-queries-received-ipv4: 4091904099 dns-udp-queries-received-ipv6: 399125012 dns-tcp-queries-received-ipv4: 23342099 dns-tcp-queries-received-ipv6: 562874 dns-udp-responses-sent-ipv4: 4071959955 dns-udp-responses-sent-ipv6: 398893049 dns-tcp-responses-sent-ipv4: 23301848 dns-tcp-responses-sent-ipv6: 562272