Lars, I know we're repeating arguments from the last decade. The choice is between (1) specifying congestion control around the substrate UDP that can be turned off if it causes problems, or (2) specifying nothing at this time and adding it later if operators want it. I guess if this can be written as a SHOULD, up to the implementor's discretion, then okay. Scott On Tue, Jan 14, 2014 at 10:29 AM, Eggert, Lars <lars@xxxxxxxxxx> wrote: > Hi, > > On 2014-1-14, at 16:23, Joel M. Halpern <jmh@xxxxxxxxxxxxxxx> wrote: >> Isn't that basically the problem of the inner traffic sender, not the problem of the tunnel that is carrying the traffic? > > no, because the sender of the inner traffic may be blasting some L2 traffic, for an L2 where that is OK behavior. But that traffic is now being encapsulated inside UDP and can hence go anywhere on the net *without the sender being aware of this*. > >> Asking tunnel's to solve the problem of applications with undesirable behavior seems backwards. > > It is the *tunnel* that performs the encapsulation and allows that traffic to go places it couldn't before. And so it's the tunnel's responsibility to make sure that the traffic it injects into the Internet complies with the BCPs we have on congestion control. > > Lars