Merge pull request #279 from quicwg/mirjak-patch-35

recommend bundle ACK_MP with PATH_RESPONSE

draft-ietf-quic-multipath.md

@@ -642,6 +642,10 @@ data packets, including 0-RTT packets, using the initial Connection ID with
 sequence number 0 after the handshake concluded.
 
 ACK_MP frames (defined in {{ack-mp-frame}}) can be returned on any path.
+If the ACK_MP is preferred to be sent on the same path as the acknowledged
+packet (see {{compute-rtt}} for further guidance), it can be beneficial
+to bundle an ACK_MP frame with the PATH_RESPONSE frame during
+path validation.
 
 ## Packet Protection {#multipath-aead}