[HECnet] Decnet over internet

FWIW, on LEGATO I currently have 8 defined Multinet DECnet links. Three are TCP and the rest are UDP. Historically I've had 18 different remote links, although not all were in use at the same time. Again, some were TCP and some UDP. The TCP and UDP links both exhibit the occasional "adjacency down" then "adjacency up" behavior. I haven't analyzed the relative frequency, but I can conclusively say that TCP doesn't fix the problem, at least for Multinet. I don't see it as a serious problem, although it is an annoyance. Searching my OPERATOR.LOG files just now, I'm going to say there are around 2 or 3 "flaps" per day. The UDP links are significantly easier to administer, however, and I've stopped adding new TCP links. 1) Multinet has no ability to configure the TCP option for you, and you have to manually edit the DECNET-CIRCUITS file to create one. And once you manually edit this file, you can no longer use the MULTINET CONFIGURE/DECNET tool (or rather, you can, but it'll erase all your hand edits!). 2) UDP is symmetrical - both ends are configured the same. TCP is inherently asymmetrical because you need an active (connecting) and passive (listening) end. Multinet does both, but you have to coordinate with the other end about who will play which role 3) All UDP connections can share the same port; all TCP connections require a unique port. This is another issue that has to be coordinated for each link. 4) Since each TCP link needs a unique port, that means each TCP link needs another rule added to my firewall. All the UDP links share one port and one rule. (Actually if you're the active end and your firewall allows outgoing connections then this doesn't apply, but everybody can't be active. Somebody has to lose the coin flip and be the listening end.) Admittedly #1 is unique to Multinet, but the rest are just consequences of a connection oriented vs non-connection oriented protocol. Bob