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
http://gadgets.boingboing.net/2009/0...th-with-1.html

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.

On 11/27/2010 10:16 PM, SF Man wrote:
> 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
> http://gadgets.boingboing.net/2009/0...th-with-1.html
>
> 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.

Most home user routers or DSL Modems/routers are setup by default to use
a NAT IP address values on the LAN side. The usual range of IP address
assigned using NAT are not able to be routed over the internet. The
user's local router knows the final physical device address and as such
is able to complete the connection to the internet for you.

When you add a second router also using NAT into the mix things get
tricky. The final router in the link at the user knows the local
devices but when it tries to forward them to the internet it gets
blocked by the second non-routable NAT address in use by the other
router or DSL/Cable Modem box using NAT.

Bridge mode basically turns off the router functions, so that the
internet IP address that comes in from the WAN goes directly to the LAN
with no change in IP address. The second router is then able to forward
it's NAT'd devices out over the internet using the routable address
being supplied by the first box. With NAT turned off a box that has
more than one "LAN" port becomes basically an Ethernet switch with all
ports showing the same IP address as supplied by the ISP or device
upline from it.

I found the review at the following YouTube link quite interesting.
http://www.youtube.com/watch?v=vOo8b...eature=related

On Sat, 27 Nov 2010 20:16:02 -0800, SF Man <(E-Mail Removed)>
wrote:

>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
>http://gadgets.boingboing.net/2009/0...th-with-1.html
>
>Can you tell me in plain English what this line is trying to tell me?
>- Why is he directing this to 'filthy pirates'?

I assume he's talking about port forwarding. Filesharers and gamers,
for example, typically need to forward certain ports to get their
respective apps working, and double NAT makes port forwarding a bit
more complicated because it has to be done twice if there are two NAT
routers connected back to back. Putting one of the routers in bridge
mode eliminates the double NAT, somewhat simplifying things for people
who need to forward ports. If you're in a category of people who don't
worry about such things, then double NAT is no worse than single NAT,
IMHO.

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

NAT has its pros and cons, but double NAT probably brings more cons
than pros for many people. Others won't see any behavioral changes at
all, so it depends on the specific situation.

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

If double NAT is a problem for you, then putting one router in bridge
mode will help because it eliminates the double NAT. On the other
hand, if you have no apps that are affected by double NAT, or even if
you do have such apps and you're comfortable with making the necessary
router config changes, then double NAT is nothing to be afraid of.

>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?

I would connect it to the LAN side of your existing router. If you do
that and it works fine for you, (no QOS issues, for example), then the
whole bridge mode argument is moot.