pprindev@wellfleet.com (Philip Prindeville) (09/04/89)
Does anyone know how closely the clocks on the NSFnet routers are synchronized? Do they run any sort of time protocol? Are any tools in use that require accurate time keeping? Such as IP Internet Timestamp options? Dave? Hans-Werner? Thanks, -Philip
Mills@UDEL.EDU (09/05/89)
Philip, I don't think HW watches this frequency, so I will try to explain what I understand is their policy. The NSS' do in fact fun a (very old and hacked) version of NTP, but chime only among themselves and a couple of handpicked stratum-1 tickers outside net 129.140. However, they (IBM and Merit) are not willing to support ubiquitous NTP access for fear of abuse, either in numbers or evil purpose. In order to encourage a more liberal agenda, I persuaded Ford Scientific Labs to donate their GOES receiver and Fuzzball to Merit, if only to operate as a standalone time server, but the actual move has not occured yet. I will of course continue to pursue this agenda and maybe someday it will happen. Meanwhile, while NTP access is blocked, ICMP Timestamp still works. Before you get further ideas, be advised the NSS' do not seem to be very reliable sources of synchronized time, for what reason I can't tell. The regional Fuzzballs are much more stable and precise, even the stratum-2 servers. Dave
pprindev@wellfleet.com (Philip Prindeville) (09/05/89)
Dave, What I had in mind was more a question of whether anyone uses ICMP timestamps to measure network delay. If so, then synchronization is fairly important. I've been playing with the idea of hacking wiretap into ANSI-SPF, and timestamps would be a good way to divine performance information. However, it would require close synchro- nization amongst the participants... -Philip