Sip registry timeout question?

Aloha,

Have a question about sip registration and timeouts. Because I have a weird problem.

By default Asterisk requires SIP peers to register every 30 mins. So what happens when you are on a call at that time?

And should re-registering drop the current call? Because that’s what happening. It’s not all the phones, just some of them. It’s just weird. I have bumped up the timeout to an hour (7200), but I know it shouldn’t be dropping the calls.

Cisco 7960Gs. 8.11 firmware.

Just wondering if anyone else has experienced something like this? Going to do a lot more tomorrow, but was hoping someone out there has some insight for me.

Thanks,
Herb