Level 1

10 points

Comcast "traffic management" blocks Extend mode of AirPort Express 'n' ???

In another thread, I posted that I was unable to access the Internet using my AirPort Express 'n' to Extend my AirPort Extreme 'n'. With the AirPort Express 'n' in the Extend mode, computers connected to it, either wirelessly or via the Ethernet port, were unable to access the Internet, even though the Network preferences of the computer showed that it had a valid IP address, and the Network preferences Diagnostics indicated that the connection appeared to be working correctly and showed all green status lights. This problem occurred only in the Extend mode of an AirPort Express 'n', and regardless of whether the AirPort Extreme 'n' being extended was in the 5.0 GHz 'n' only mode, the 2.4 GHz 'n' only mode, or the 'n' (b/g compatible) mode. Both AirPorts were running the latest firmware version 7.3.1, all IP and DNS information was verified to be correct, and OpenDNS addresses were tried with no effect on the problem.

In this previous thread, three other people reported the same problem with the same symptoms, and two people reported that they were NOT having the problem and that they WERE able to access the Internet with their AirPort Express 'n' in the Extend mode. Of the people reporting the same problem, ALL reported that their ISP was Comcast. Of the people reporting that their Extend mode WAS working, ALL reported that their ISP was NOT Comcast.

This seemed like too much of a coincidence to ignore, so I have started this thread to see whether or not other people are experiencing the same problem with their AirPort Express 'n' in the Extend mode and to see what ISP they are using.

Here are the results from the previous thread, and I will keep a running total of any new results reported.

People with Comcast ISP whose Extend mode is NOT working --- 4
GARYsParries
devasolomon
Boston Dog
dannym098

People with Comcast ISP whose Extend mode IS working --- 0

People without Comcast ISP whose Extend mode is NOT working --- 0

People without Comcast ISP whose Extend mode IS working --- 2
cardsdoc
MusicMan0725

For those of you that have not been keeping up with the news reports about the Comcast "traffic management" issue, Comcast has been accused by BitTorrent and the FCC of conducting unfair practices to manage their Internet traffic for the purpose of keeping traffic flowing smoothly. As a result, Comcast has agreed to discontinue these practices by the end of 2008.

MacBook Pro 17" Core Duo, Mac OS X (10.5.2)

Posted on Apr 5, 2008 6:43 AM

237 replies

kfipp

Community Moderator

May 15, 2008 12:08 PM in response to Killermink

"Extend a network" is defiantly better than WDS. The extend a network feature only exists when extending the range of an 802.11n airport product with another 802.11n enabled airport. It is sometimes referred to as dynamically extending the range of the network and doesn't cut your bandwidth noticeably. A wds network will effect your network bandwidth by half per each "jump" made on the network. Basically if you set up a wds network with 2 expresses extending the range of an extreme you have cut your network bandwidth in half and then in half once again. Any time you can avoid extending the range through WDS you should and dynamically extending the range is the best solution when an increase in signal strength in a remote location is needed. Problem is it's obviously not working right at this moment.

GARYsParries Author

Level 1

10 points

May 15, 2008 1:04 PM in response to kfipp

Kfipp, thanks for the technical info regarding the advantages of the Extend mode vs. WDS. We are always appreciative of someone who knows more than we do. 🙂

Along those same lines, do you happen to know if there is any limit (either practical or absolute) on the number of airport bases you can have extending your main airport base?

Also, do you happen to know, regarding signal strength, if you have two Extremes each extending a third main Extreme, all equally spaced in a straight line, is there any advantage to putting the main Extreme in the center of the straight line with an extending Extreme at each end, or would it work just as well to have the main Extreme at one end of the straight line with one extending Extreme in the center and one extending Extreme at the other end?

Thank you in advance for any additional information you can provide.

jseg2005

Level 1

40 points

May 16, 2008 4:58 PM in response to GARYsParries

I just need to add real fast that yes seperation is good but please remember that most routers come on these channels for that reason. 1 6 and 11 are most often the most crowded channels. I recommend using channel 3 or 9. It is much less common to see someone on these channels. If you have a Mac, try downloading istumbler. Free application that will scan the area for networks and tell you the channels. I might also add that the channels generally only overlap by about 2 channels. In other words, 1 orverlaps two, but barely interferes with 3, etc. up the list.

GARYsParries Author

Level 1

10 points

May 16, 2008 6:37 PM in response to jseg2005

Good point, Jseg. It should also be note that, if you use the 5 GHz n-only mode, interference becomes almost a non issue. There are no phones in that frequency range, far fewer routers, and many more channels from which to choose.

May 21, 2008 3:05 PM in response to GARYsParries

Another Comcast customer with the same problem.
In my case, it works fine when I extend an Airport Extreme-n with an Airport Express-n...but only one. The moment I connect a second Express, it all collapses.

Here's what I wrote on another thread. This is getting very annoying.

Anyone from Apple reading these? Can someone from Apple talk to someone from Comcast?

I keep trying to diagnose the problem. Here's an update:

1) I set up my Airport Extreme-n as the base station for my wireless network. It is set up allowing wireless network to be extended.

* All works well when it's up by itself

2) I plug in an Airport Express-n in another part of the house. The settings are to "extend" the wireless network,

* All works well when it is only the Extreme base plus this Express extender

3) I plug in one more Airport Express-n in another part of the house. i use the exact identical settings as the unit I added in number 2 above.

* All the units are visible to my Airport Utility; I get full bars; BUT I GET NO INTERNET.

Ideas?

jseg2005

Level 1

40 points

May 21, 2008 4:21 PM in response to DavidDavid

As I mentioned before, the Extend mode is for a maximum of two devices. It's dynamic nature does not allow for multiple bases in a remote relay situation. if you are using more than 2 you need to be using standard WDS. This information I have confirmed with several product specialists.

jseg2005

Level 1

40 points

May 21, 2008 4:33 PM in response to GARYsParries

I haven't been able to post for a few days, anyways... Join with wired clients actually routes fine. It is a little odd though. I have a sat box connected via ethernet and it only receives an ip address about half the time. For the time being I set it to join with wired clients and that fixes my issue. I only have a 2 bedroom appartment to cover for my room mate and one works fine. Peculiar issue though. I suppose I may have time to sit down and finish testing next week. By the way, has anyone tried rolling back the firmware version? I will make sure to try that if not.

May 21, 2008 4:57 PM in response to jseg2005

Thanks Jseg. That is very useful info, although doesn't make me happy. You would think Apple would tell you that in manuals, etc.

If I go all WDS will I still be able to use "n" or does everything degrade to g?

GARYsParries Author

Level 1

10 points

May 21, 2008 5:18 PM in response to GARYsParries

David, since you would be the FIRST of about 30 Comcast users who have posted on this thread to successfully access the Internet with an Express extending an Extreme, here is what I think is ACTUALLY happening.

When you have one Express extending an Extreme, you are assuming that your computer in the vicinity of the Express is wirelessly connected to the Express, but it is actually wirelessly connected to the Extreme, and THAT is why you are able to access the Internet. You can prove or disprove this theory by connecting your computer to the Ethernet port of the extending Express, turning off your computer's Airport, and checking if you can still access the Internet. My guess is that you will NOT be able to access the Internet.

If you do not have an extra Ethernet cable, another way to check is to start Airport Utility, select your Airport Express base, click on the Manual Setup button, click on the Advanced icon, click on the Log and Statistics button, click on the Wireless Clients tab, and check the list of wireless clients for the Airport ID of your computer. My guess is that it will NOT be in that list; rather, it will be in the list for your Airport Extreme base, which you can check the same way you checked your Express.

So far, the only way reported to extend your wireless network on Comcast and successfully access the Internet is with an Extreme extending an Extreme, or an Express extending a Time Capsule. If you use the WDS mode, you will be limited to 'g' speeds only, no 'n' speeds.

Jseg, do you mean that the extend mode is limited to two bases TOTAL, or two bases extending a third base? I currently have two Extremes extending a third Extreme, and everything is working perfectly.

Message was edited by: GARYsParries

jseg2005

Level 1

40 points

May 21, 2008 5:50 PM in response to GARYsParries

Two bases total, and yes I believe it does degrade to g. According to my knowledge extend is the only way to get n. Please keep in mind however that according to the draft specs, n already has up to double the operating range of g. Very few people need more range than an extended network provides. If you do not absolutely need to extend, don't. Every hop slows your network down. Some people will do 4 base stations within 10 feet of each other and extend on each of them because they can. Do not do this. Extending the range where not needed can only have a negative impact on network performance. By the way that last comment was aimed at WDS not extend mode which is very similar to WDS and could easily be referred to as Dynamic WDS.

May 21, 2008 6:12 PM in response to jseg2005

Thanks Gary and Jseg.

Gary, you are absolutely right; I tested as you suggested and realized I fell into that illusion. Indeed I am connected to the Extreme base and not to the Express.

Clearly I have not avoided the Comcast problem. The only thing I can say is that even my set up fails when there are two Express units attached.

Jseg, I wish I could avoid the need to go further, but I can't. Without some form of extension, my signal degrades across walls and rooms. I had no problems when I was with the old Extreme and Express units. thought I'd get some speed gains going to n, but instead I went to "stop". Don't they test these things?

I'll stay tuned watching the Apple/Comcast solution. If they are reading this, please take this seriously.

GARYsParries Author

Level 1

10 points

May 21, 2008 7:23 PM in response to GARYsParries

Jseg, here's what I think your product specialists were saying about Extend mode vs. WDS. With WDS you have three choices for your base: main, relay, or remote. With Extend mode, you only have TWO choices for your base: main or remote (no relay choice).

With WDS, a relay can extend a main, and then a remote can further extend that relay. This is not possible with Extend mode since there is no relay; however, you can still have multiple remotes extending a single main in Extend mode (as I have proven with my setup), but you cannot have one remote extending another remote.

David, glad you were able to verify your setup. My situation was originally very similar to yours. What I ended up doing was buying a second Extreme to wirelessly extend my first Extreme wireless network running in 5 GHz n-only mode. This mode gets out much better than the n-b/g compatible mode and is much less susceptible to noise, plus it is more than twice as fast. Then I connected my Express via Ethernet to the second Extreme and used it to Create a new b/g compatible network (with a different name than the 5 GHz n-only network) in order to connect my 'g' devices. These two networks work seamlessly together as a SINGLE local network, so clients of one base have complete local access to clients of the other two bases.

With this setup, I have Internet access from all bases, and it covers the area so well that I don't even need my third Extreme, which I only hook when people ask me if it is possible to have multiple remote bases extending a main base. 🙂

May 21, 2008 8:43 PM in response to GARYsParries

Gary,
Awesome, what an excellent and elegant solution, I will definitely try it.
Is your second Extreme also an "n"? I have my old b/g square Extreme and also an old "dome" b/g Extreme.

GARYsParries Author

Level 1

10 points

May 22, 2008 7:13 AM in response to GARYsParries

David, all bases used in the Extend mode of the 5 GHz n-only wireless network must be 'n' bases. My Ethernet connected Express is an older 'g' base, and that's fine because I am using it to Create a b/g compatible wireless network as an offshoot of the 5 GHz n-only network. If you have any older 'g' Extremes, they would be perfect for connecting via Ethernet to one of your 'n' Extremes, and then using them (as I am using my Express) to Create b/g compatible offshoots of the 5 GHz n-only network (each with a different name), all working as a single local network.

I know you can have at least 3 'n' Extremes (1 main and 2 remotes) in your 5 GHz n-only wireless network, so you could connect a 'g' base (or an 'n' base used in n-b/g compatible mode) to each via Ethernet. That would give you both excellent 'n' and 'g' coverage. I would first try a wireless network with just 2 'n' Extremes (1 main and 1 remote), and a 'g' base connected to each via Ethernet, to see how that works before purchasing any additional 'n' Extremes. As I said, I have a third 'n' Extreme, and I am not even using it because the coverage is so much better in the 5 GHz n-only mode compared to my original setup using the 'n' Extremes in the n-b/g compatible mode.

If you do end up using more than 2 'n' Extremes, make sure the main Extreme is centrally located to the remotes, as in a hub, rather than located at one end, as in a chain.

Hope that helps. Good luck with your setup.

May 22, 2008 1:01 PM in response to GARYsParries

Gary, you are awesome.

Top marks for your help!

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Comcast "traffic management" blocks Extend mode of AirPort Express 'n' ???