1:1 translations refer to the case in which each CE is assigned a distinct public IPv4 address; that is, there is no public IPv4 address sharing between the CEs. In this case, the PSID field is 0 and the sum of lengths for the IPv4 rule prefix and EA bits is 32. In other words, all the EA bits represent the IPv4 suffix. The public IPv4 address of the CE is created by concatenating the Rule IPv4 Prefix and the EA bits.
IPv4 Prefix translations refer to the case where an IPv4 prefix is assigned to a CE. In this case, the PSID field is 0 and the sum of the lengths for IPv4 rule prefix and EA bits is less than 32.
In both preceding cases, the translations are protocol agnostic; all protocols, not just TCP/UDP or ICMP, is translated.