[EPEL-devel] Questions about the PTPd package

I need to create a reliable and accurate synchronization between two CentOS 6 machines connected through a direct Ethernet connection. I've seen that on Linux several implementations of the IEEE 1588 Precision Time Protocol (PTP) <https://en.wikipedia.org/wiki/Precision_Time_Protocol> exist: - PTPd <http://ptpd.sourceforge.net>;: - Apparently, this is the original implentation - Apparently, it is still maintained <http://www.github.com/ptpd/ptpd> - PTPd2 <http://ptpd2.sourceforge.net>;: - A new version meant to supersede the previous implementation - Apparently unmaintained - Available only in the EPEL repositories as ptpd package - PTPv2d <http://code.google.com/p/ptpv2d>;: - A further implementation - Unmaintained as well - linuxptp <http://linuxptp.sourceforge.net>;: - A specific implementation for Linux - Maintained - Available on the CentOS repositories - Suggested by the RedHat documentation for both RedHat 6 <https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/... and RedHat 7 <https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/... My questions follow: - Does the ptpd package provided by EPEL refer to the ptpd or to the ptpd2 project ? (the EPEL package is called "ptpd" while the included binary is called "ptpd2"...) - Why does EPEL provide PTPd2 while RedHat suggests and already provides linuxptp on its own repositories ? Which are differences between PTPd2 and Linuxptp in terms of reliability and timing accuracy ? Many thanks and best regards.