On Tue, Jan 29, 2019 at 08:07:49AM -0800, Richard Cochran wrote: > On Tue, Jan 29, 2019 at 10:00:37AM +0100, Miroslav Lichvar wrote: > > Isn't that negligible when compared to the sync/announce traffic? > > Not to the master or to the network itself. I might have 1000 slaves > renewing every 30 seconds.
Ok, but compare it to all network traffic that is generated by PTP. With 1000 slaves in default configuration the master is on average sending each second 1000 sync messages, 500 announce messages and responding to 1000 delay requests. That's 3500 messages per second in the network. Now, 1000 slaves renewing their grants every 30 seconds adds to that ~66 messages per second (1.9% of all traffic). With the proposed 3600 second maximum duration (2700 second renewal interval) that would be only ~0.7 messages per second (0.02% of all traffic). That's negligible. With significantly longer durations I think it's more likely that the master will be sending messages to slaves that are powered off without canceling their grants, or changed their IP address, wasting much more bandwidth than the grant renewals. If you feel one hour is too short, would one day work for you? -- Miroslav Lichvar _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
