It was my mistake. My local network was blocking my outgoing telnet connection. Once I got around that, the ports were indeed open.
I am running a nodejs daemon that is listening on a high-numbered port (over 9000!). I can successfully connect to the daemon using localhost, but I cannot connect to the daemon externally.
The wiki sez:
DH Live Support confirmed that the ports should all be open on a VPS.
Any clue why I can't connect externally? Am I missing something obvious?