Merge pull request #2001 from martinduke/patch-30

Refine minimum DCID length of Initial

draft-ietf-quic-transport.md

@@ -1318,6 +1318,10 @@ packet is received from the server, the client MUST use the same value unless it
 abandons the connection attempt and starts a new one. The initial Destination
 Connection ID is used to determine packet protection keys for Initial packets.
 
+A client SHOULD select a Destination Connection ID length long enough to fulfill
+the minimum for every QUIC version it supports. This increases the chance
+subsequent Initial packets are routed to the same server.
+
 The client populates the Source Connection ID field with a value of its choosing
 and sets the SCIL field to match.