Media for Ooma double-NAT network unless you put your existing router in bridge mode

Ooma double-NAT network unless you put your existing router in bridge mode

I am considering buying & hooking up the Ooma Telo with my line-of-sight ISP and Linksys WRT54G wireless router.

Reading the Ooma reviews, I come across this line: "Note, you filthy pirates, that this will double-NAT your network unless you put your existing router in bridge mode."

In this review: Review: A month with Ooma, the lifetime free VoIP system

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Can you tell me in plain English what this line is trying to tell me?

- Why is he directing this to 'filthy pirates'?

- If network address translation is good, is double NAT better? Why?

- Is he actually recommending "bridge mode" (whatever that is) or not?

I know the basics, so, if you can tell it to me with basic talk, that would be great. Basically, if I get this Oooma Telo VOIP unit, would I want to hook it up before the router, or after? And would I want to put my router in this so-called bridge mode or not?

PS: I'm not a pirate so I'm not sure if any of this applies.