Another update. My work proxy likes to terminate connections that become persistant. From my tests, it seems like this happens every 15 minutes. This ought to be a problem only for songs over 15 minutes long, but the DB connection is opened persistantly, and when it is lost, the entire connection to the share and any music playing is gone too.
Interestingly, I tried keeping an ssh connection open to my server, in the same way, and it lasted about 50 minutes before being disconnected. Perhaps it has more to do with the amount of data transferred.
As such, I’ll have to discard using the proxy to forward, and try the other approach: run mt-daapd locally with a cached DB, and hack it to open remote connections for the mp3’s. Or just buy an external hdd and copy them. 🙂