On 3/2/2015 3:14 PM, David Lang wrote: > On Mon, 2 Mar 2015, Joe Touch wrote: > >> On 3/2/2015 1:40 AM, Brian Trammell wrote: >> ... >>> The real solution is to create a utility called "ping" that uses >>> traffic that gets prioritized the same way as the traffic you care >>> about instead of ICMP echo request/reply. Users don't care about >>> the packets on the wire so much as they do that you're supposed to >>> ping things. >> >> There are three separate problems: >> >> 1. a ping that doesn't use ICMP >> there are dozens of these >> >> 2. needing a reflector >> ping gets around this only because the reflector is widely >> deployed (and integrated into most OSes) >> >> 3. using the same port as the traffic you care about >> transport protocol is only one problem (ICMP being a "transport >> protocol" by virtue of using the IP protocol number field) >> >> the other is differential prioritization based on port number >> >> there's no easy solution to that; >> every service would need an integrated >> ping reflector >> >> I suspect #3 is the ultimate killer of this idea. > > The service you are trying to contact acts as a reflector for TCP > traffic. If you send a syn you will get back a syn-ack from the TCP > stack of the receiving system.
Sure, but SYNs and SYN-ACKs don't get prioritized the same as non-control TCP segments. And they could have been spoofed by a middlebox. Joe _______________________________________________ Cerowrt-devel mailing list Cerowrt-devel@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cerowrt-devel