[Cerowrt-devel] [Bloat] [aqm] ping loss "considered harmful"

David Lang david at lang.hm
Mon Mar 2 13:41:58 EST 2015

 On Mon, 2 Mar 2015 15:45:10 +0100, Brian Trammell wrote:
>> On 02 Mar 2015, at 11:54, Jonathan Morton <chromatix99 at gmail.com> 
>> wrote:
>>> On 2 Mar, 2015, at 12:17, Mikael Abrahamsson <swmike at swm.pp.se> 
>>> wrote:
>>> On Mon, 2 Mar 2015, Brian Trammell wrote:
>>>> Gaming protocols do this right - latency measurement is built into 
>>>> the protocol.
>>> I believe this is the only way to do it properly, and the most 
>>> likely easiest way to get this deployed would be to use the TCP 
>>> stack.
>>> We need to give users an easy-to-understand metric on how well 
>>> their Internet traffic is working. So the problem here is that the 
>>> users can't tell how well it's working without resorting to ICMP PING 
>>> to try to figure out what's going on.
>>> For instance, if their web browser had insight into what the TCP 
>>> stack was doing then it could present information a lot better to the 
>>> user. Instead of telling the user "time to first byte" (which is L4 
>>> information), it could tell the less novice user about packet loss, 
>>> PDV, reordering, RTT, how well concurrent connections to the same IP 
>>> address are doing, tell more about *why* some connections are slow 
>>> instead of just saying "it took 5.3 seconds to load this webpage and 
>>> here are the connections and how long each took". For the novice user 
>>> there should be some kind of expert system that collects data that 
>>> you can send to the ISP that also has an expert system to say "it 
>>> seems your local connection delays packets", please connect to a 
>>> wired connection and try again". It would know if the problem was 
>>> excessive delay, excessive delay that varied a lot, packet loss, 
>>> reordering, or whatever.

 There is hping3 that lets you do 'ping' and 'traceroute' on TCP and UDP 
 to any port (with different flags set if needed). Unfortunantly many 
 people are not familiar with it. I've also run into problems that the 
 stock build doesn't work right if you have too many interfaces (IIRC I 
 ran into problems around 8 interfaces, but since I was working with 
 firewalls that had up to 22 interfaces in use, I could be off by quite a 
 bit on that number)

 David Lang

More information about the Cerowrt-devel mailing list