[2] [CITE@en[RFC 781 - Specification of the Internet Protocol (IP) timestamp option]], [TIME[2021-04-11T09:27:02.000Z]], [TIME[2021-04-21T08:52:47.659Z]] <https://tools.ietf.org/html/rfc781>

[1] [CITE@en[RFC 792 - Internet Control Message Protocol]], [TIME[2021-04-04T07:48:00.000Z]], [TIME[2021-04-16T07:35:31.216Z]] <https://tools.ietf.org/html/rfc792#page-16>

[4] [CITE@en[RFC 3252 - Binary Lexical Octet Ad-hoc Transport]], [TIME[2019-03-03T20:11:48.000Z]], [TIME[2021-04-21T09:02:34.530Z]] <https://tools.ietf.org/html/rfc3252#page-11>

[3] [[TCP Timestamps]] とは違います。