As I have noted in the last email, timestamping all packets is too costly to afford to. We have done some experiments on our products, the degrading of performance is unacceptable. That is why we need to distinguish 1588 packet from others with high priority, and is the crucial reason that we equip WESP with identifier.
Yang ________________________________________ 发件人: Kevin Gross [[email protected]] 发送时间: 2011年10月20日 11:13 到: Nico Williams Cc: Danny Mayer; Cui Yang; [email protected]; [email protected]; [email protected]; [email protected] 主题: Re: [TICTOC] [IPsec] Review request for IPsec security for packet based synchronization (Yang Cui) The IEEE 1588 standards are quite abstract so you won't find these implementation details there. You need to read NIC datasheets. Many of these are only available under NDA. On Wed, Oct 19, 2011 at 8:36 PM, Nico Williams <[email protected]> wrote: > On Wed, Oct 19, 2011 at 9:21 PM, Kevin Gross <[email protected]> wrote: >> It would be nice to have timestamps on every packet but, for whatever >> reason, this is not how most existing 1588 hardware works. Current hardware >> keys off specific protocol identifier fields in packets and takes a >> timestamp on match. There's some small amount of hardware buffer dedicated >> to holding timestamps. > > This is key, and needs to be stated in the I-D, quite possibly in the > abstract. I guess it's time to set aside time to go read IEEE 1588... > -- Kevin Gross +1-303-447-0517 Media Network Consultant AVA Networks - www.AVAnw.com, www.X192.org _______________________________________________ IPsec mailing list [email protected] https://www.ietf.org/mailman/listinfo/ipsec
