Hi all, to synchronize a couple (6-8) PCs I want to use one PCs PTP master and the others as PTP slaves. To interconnect the PCs I can use a PTP capable switch. However these switches are fairly expensive. The first question I have: How does a "standard" Ethernet switch perform? Which accuracy will be possible if no other traffic is running over the switch but PTP packets?
To avoid a PTP capable switch I can think of a solution to use one PC as PTP master, to plug in two 4-port NICs in this master PC and use point-to-point connections to the other PCs. Assume the Ethernet devices to be used by the PTP master are eth1, eth2, ...eth7 it should be possible to run something like ptp4l -p /dev/ptp1 -i eth1 & ptp4l -p /dev/ptp2 -i eth2 & ... ptp4l -p /dev/ptp7 -i eth7 & Is this assumption correct? Is it possible to set up a system like that. A different approach could be to run something like a "chain" of point-to-point Ethernet connections: [PC MASTER] --- (eth) --- [PC 1] --- (eth) --- [PC 2] --- (eth) --- [PC 3] --- (eth) --- [PC 4] --- ... The first PC (PC MASTER) acts as overall time master. It is the master on the Ethernet connection between PC Master and PC 1. PC 1 is slave on this Ethernet and acts as a master on the Ethernet between PC 1 and PC 2. etc. Doing this, the accuracy decreases with each member of the chain; however the overall accuracy could be good enough. My question is here: How does the configuration of PC 1 ... PC 7 look like? As PC 1 ... PC 7 have two PTP clocks running, these clocks have to be synchronized. Is this done via phc2sys? If yes, do I have to synchronize directly from PTPx to PTPy or does it work via the PCs System clock? Thanks for any hints or recommendations Regards Mathias ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
