With version 2.0, we have added the capability to construct ICMPv4/v6 Echo streams, which we refer to throughout the document as iStreams (note the ‘i’). PacketSmith is the only known tool capable of constructing ICMP (when the version is not specified, both v4 and v6 are considered) Echo streams, similar to TCP/UDP streams. With this feature, we can interrogate and dissect the ICMP Echo protocol in various ways to capture its unique behavioural and semantic characteristics.