RE: MOPO and the 'ping' probes

On Tue, 2005-03-08 at 10:06, Timothy Liu wrote:
> There is an approach base on same idea, I am not sure if this has been
> brought up before. Why not send DPD with the same sequence number
> (simultaneously?) to all the paths that the peer wants to test? From the
> other side it can treat is as retransmission and resend the DPD response
> through the different paths. The retransmission policy on the requester
> side is only to retry along the primary path.

yes, but you also need to handle the case when the sender didn't have enough
window for even one request because all window slots were occupied by messages
which hadn't gone through because the preferred path was broken..

One solution would be to use a real request instead of a DPD ping
when you actually have something real to send.

I'd think simultaneous probes would be considered unfriendly to the network;
non-simulataneous (delay of a large fraction of the RTT or so between each probe)
might be nearly as good at finding a path without generating nearly as much redundant
traffic...