Please also note that when we moved the installer to an RPM downloaded via YUM, there are dependency checks in place for any essential packages required to run the installer (dialog, epel-release, etc). Thus any package required to run or install 128T do not have to be pre-downloaded and installed separately. This greatly speeds up the installation process.
As Adam pointed out, some of the other packages (tcpdump, lshw, bash-completion) are helpful troubleshooting tools in Linux outside of 128T.