> I was just interested in whether the behaviour have been defined for those > who need early failure detection (systems with failover capabilities) and > are willing to pay for the additional bandwidth used (financial sector). Why didn't you say so in the first place? I believe that the common practice is to send two timestamped copies of every packet which are routed over two distinct network paths, i.e. not sharing circuits or routers, and then the receiver waits for both copies to arrive. If the delay between the two identical packets is too large, then the network is at risk, and you should assume the worst, i.e. the information is out of date and should be discarded. The timestamps are there to show you the variation in latency of the first packet in the pair to arrive. A couple of ways of sending two copies via two diverse paths are to use MPLS where you can set up two LSPs over different topological paths.or to use two different multicast trees which are routed differently by your cooperating network provider. Either SFTI or NYSE had published something about this which I downloaded and read about 6 years ago. Can't remember all the details but I remember that the intro talked about the transition from bisync to IP. You really should be asking this kind of question elsewhere where the financial types hang out. Latency is so important that even the guys who are primarily software developers tend to know a lot about how to do this. --Michael Dillon _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf