I'm confused by the options available under the "Simul Ring" settings and I can't seem to find any explanation on this forum.

I want to use the "Ring All" option to ring both my VOIPo phone and my mobile phone simultaneously. More specifically, I'm confused about what "Ring Seconds" and "Auto Answer" mean. When I initially select the "Ring All" option it defaults the "Ring Seconds" on the default "VOIPo Line" to zero. But, when I enter my mobile number as the destination in the second entry field under the default VOIPo Line and hit the save button, the "Ring Seconds" field defaults to 20.

What should be the proper "Ring Seconds" and "Auto Answer" settings to ensure that I have the option to answer incoming phone calls on either my mobile phone or my home VOIPo phone? And what does "Auto Answer" mean?