Airport Extreme and DOCSIS 3.0

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Level 3

993 points

Airport Extreme and DOCSIS 3.0

Today in New York City Time Warner Cable unveiled Wideband Internet using DOCSIS 3.0. I placed an order and they're here next week. I assumed I would still run my Ethernet cable from their new modem to my AXtreme and continue as I have.

They said on the phone that the modem TWC will bring is a router and I can connect wirelessly to it directly.

Any thoughts? Caveats? I have 2 AExpress connected to my Airport, one wired, one wireless. Ditto three Macs; two wired, one wireless. If I run everything from my AExtreme as always the only difference is the Modem they bring into the house.

But I have no idea if I will still be able to use my current AExtreme setup. Does anyone know about DOCSIS 3.0 and how it might work with an Airport setup already in place?

Unibody 17 matte, Mac Pro Quad core, Mac OS X (10.6)

Posted on Sep 24, 2009 1:16 PM

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Answer 1

Best reply

Duane

Level 10

124,267 points

Sep 24, 2009 6:23 PM in response to Eddie Strauss

DOCSIS 3.0 is the communication between the cable system and the cable modem. It has nothing to do with the Ethernet connection coming out of the cable modem.

None of Apple's base stations have anything to do with DOCSIS 3.0 and don't need to since they don't connect directly to cable internet service.

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Answer 2

Eddie Strauss Author

Level 3

993 points

Sep 24, 2009 6:31 PM in response to Duane

Right. I want to assume everything stays the same but the cable line into the apt. carries a faster signal to a new modem which still gets connected (via Ethernet) to my Airport.

I ask only because the rep. on the phone (naturally) didn't know much about how I'd use my own Router because as far as he knows the new Cable Modem is a router with wireless transmission and he thought I'd be using their Modem for everything and not my own.

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Answer 3

Tesserax

Level 10

148,769 points

Sep 24, 2009 6:38 PM in response to Eddie Strauss

One thing to take into consideration is if what TWC sends you is actually a combination modem/wireless router, you may need to reconfigure the 802.11n AirPort Extreme Base Station (AEBSn) as a bridge so that you don't get double-NAT errors with having two routers in series.

So, for example, if the new configuration is: TWC modem/router > AEBSn >>> AX, where ">" = Ethernet & ">>>" = wireless, then the AEBSn will need to be reconfigured as a bridge. This will allow the TWC router to provide both NAT & DHCP services for the entire network.

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Answer 4

Eddie Strauss Author

Level 3

993 points

Sep 24, 2009 6:47 PM in response to Tesserax

Thank you for that. It was always in my mind to ask if I would need to change the AEBSn to Bridge. I don't know too much about it but I do remember reading there are reasons to use Bridge mode (DSL?) at home. Perhaps I need to wait until I get the modem and hope the installer knows this much.

In the meantime I thank you very much giving me some heads up knowledge.

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Answer 5

Tesserax

Level 10

148,769 points

Sep 24, 2009 7:04 PM in response to Eddie Strauss

In this case think of bridge mode as a means to disable your AirPort's NAT & DHCP services. NAT allows you to share a single IP address, provided by your ISP, to multiple devices on the local network. DHCP is a service which dynamically assigns IP addresses to these same devices. Most Internet routers provide both DHCP server & client services.

When you have two routers, with both of these services connected in series, you will receive double-NAT errors.

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Answer 6

Eddie Strauss Author

Level 3

993 points

Sep 25, 2009 6:17 AM in response to Tesserax

Will I know a double NAT error when I get one? Is it a matter of 'I either get on the internet or I don't depending on whether I'm in bridge mode?' Or is it more subtle?

Also, if their new Modem is really a router/broadcaster too, and my AEBSn is in bridge mode, will I have two wireless networks in my apt., theirs and my own Airport created one? And is that ok?

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Answer 7

Tesserax

Level 10

148,769 points

Sep 25, 2009 7:37 AM in response to Eddie Strauss

Will I know a double NAT error when I get one?

Yes. Most likely, the status light on the AEBSn will flash amber letting you know there is a configuration problem.

Is it a matter of 'I either get on the internet or I don't depending on whether I'm in bridge mode?' Or is it more subtle?

Actually, it could be both. Typically it shows up as the inability of clients connected to the second router to access the Internet.

Also, if their new Modem is really a router/broadcaster too, and my AEBSn is in bridge mode, will I have two wireless networks in my apt., theirs and my own Airport created one? And is that ok?

Yes. Whether it is ok or not, will really depend on your networking requirements. You could, for example, disable the wireless on either the new device or the AEBSn ... or you could run each wireless network in its own radio band (2.4 & 5 GHz) to take advantage of what each band would offer and/or to support a wide variety of wireless clients.

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Answer 8

Eddie Strauss Author

Level 3

993 points

Sep 25, 2009 7:43 AM in response to Tesserax

Thank you SO much for your expertise. I won't mark this solved until I actually get it. But I don't mind praising you in the meantime 🙂

(Also - it's expensive. I have until next Thurs. to change my mind and I'm still debating.)

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Answer 9

Eddie Strauss Author

Level 3

993 points

Sep 25, 2009 8:26 AM in response to Eddie Strauss

Can the Airport Base Station be in Bridge mode wirelessly?

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Answer 10

Tesserax

Level 10

148,769 points

Sep 25, 2009 10:53 AM in response to Eddie Strauss

Yes.

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Answer 11

Sep 25, 2009 6:56 PM in response to Tesserax

How will this affect Back to My Mac or Screen Sharing when router functions are handled by an non-Apple device?

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Answer 12

Tesserax

Level 10

148,769 points

Sep 25, 2009 7:59 PM in response to ronkennedy

Sorry, but I don't see how this question relates to the one provided by the OP. Would you please start a new post and describe your current network configuration and what your requirements are. Also include what you have already tried. Thanks!

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Answer 13

Sep 26, 2009 5:40 AM in response to Tesserax

Will do; the relation was whether bridge mode and disabling NAT/DHCP on the Airport would disable Back to My Mac, i.e. Do these built-in functions BTMM and Screen Sharing require an Apple Router to work?

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Answer 14

Eddie Strauss Author

Level 3

993 points

Oct 8, 2009 1:37 PM in response to ronkennedy

I posted my experience here: -- not realizing I was in a different thread.

http://discussions.apple.com/thread.jspa?messageID=10306616#10306616

I'm up and running with DOCSIS 3.0.

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Answer 15

Eddie Strauss Author

Level 3

993 points

Oct 8, 2009 4:41 PM in response to Eddie Strauss

If I'm going to learn from today's experience I need to ask this question:

When the TWC modem was first hooked up it was as a router. Airport instantly informed me that there was double NAT and I should put it in Bridge mode. After I did that I could connect one computer to it wirelessly - but not another.

The TWC Level 3 tech said that was right as my Airport in Bridge mode would only allow one connection; it would pass only the address of the TWC modem. But that was never a warning given. I expected to have my whole network as set up - only with no conflicts.

The question is how would I have been able to get my network working as it was with the TWC modem in it's non-Bridge state? Would this be where "Distribute a range of IP addresses" comes in? Did I need to assign numbers manually?

There are many reasons why the current setup is advantageous. The TWC modem is in Bridge mode (they do that by sending codes through the cable line from their offices), and my Airport is "Sharing a public IP address."

I just wonder how or if I could have made it work the other way.

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