Still trouble staying registered (Broadvoice)

From the beginning I have had trouble keeping my trunk(s) registered on Broadvoice. Ever so often they fail, and I have to re-register by hand. Not good. This morning, it failed, and I simply ran a “sip reload” from the CLI. Nothing. No change. Then I went into my hosts file, changed the IP address for sip.broadvoice.com, did another “sip reload” and my connection was working again. Since the only thing I changed was the broadvoice proxy, it seems to me that there is something on their side.

Now, they did tell me to set the re-registration to 60 seconds. How do I do that? I tried maxregistry=60000 in the peer section of the trunk, but that does not seem to have changed anything. Looking at the log, I see: “Expiry for sip.broadvoice.com is 30 sec”.
So, how do I set the re-registration time?

Another thing that bothers me a bit is that I have set

nat=route
qualify=yes

which, according to information I got here, instructs the system that a NAT is present. Yet looking at the log again, I find “No NAT” everywhere, for example:

[Sep 27 11:02:54] VERBOSE[2966] chan_sip.c: — (9 headers 0 lines) —
[Sep 27 11:02:55] NOTICE[2966] chan_sip.c: – Re-registration for [email protected]@sip.broadvoice.com
[Sep 27 11:02:55] VERBOSE[2966] chan_sip.c: REGISTER 10 headers, 0 lines
[Sep 27 11:02:55] VERBOSE[2966] chan_sip.c: Reliably Transmitting (no NAT) to 206.15.156.221:5060:

any ideas?