[rrsears]

Hi. I have a Snow Airport Extreme that I'm using with a G4 MDD. I just purchased a Motorola SB6120 DOCSIS 3.0 cable modem and I noticed that when connected to the Extreme I was getting about the same download speed as my older DOCSIS 2.0 modem. I unplugged the Ethernet cable from the Extreme and plugged it directly into the MDD. The speed jumped more than 10Mbps.

I was wondering that since the MDD has a gigabit ethernet and the Snow Extreme has 10/100 but not gigabit, this is what caused the slowdown. If this is so, would purchasing a new "n" standard airport extreme (with gigabit ethernet ports) bring the speed up the same as plugging the ethernet cable directly into the computer?

Rick

[rrsears]

I want to correct something. I don't have a "Snow" Base Station. It's a round Airport Extreme 802.11g. Sorry about that!

Rick

[ghporter]

Welcome to our forums!

Gigabit Ethernet adapters are all backward compatible, and feeding a gigabit card from a 10/100 source won't change how fast the data gets through to the computer. On the other hand, every time you turn off a cable modem and connect it to a different device (computer versus router), the modem re-connects to both ends; changing connections could simply result in having the router get synced to the source at a higher data rate, independent of whether it's connected to a computer or a router.

Speed differences can be from the practical maximum data rates through wired Ethernet connections as compared to the practical max through a wireless connection.

What sort of speed are you getting through the Extreme and what sort of speed did you get without it? Did you get that speed increase by changing from a wireless connection through the Extreme to a wired connection without the Extreme? A true 10/100T system should get reasonable maximum throughput of up to 70Mbps (that's mega BITS per second), while a reasonable max throughput over an 802.11G wireless connection should be in the neighborhood of 35-40Mbps (again that's BITS).

Further, different cable providers can have different capacities (and customer limits), so knowing who your cable company is and your city will help us help you. Let us know who your provider is and where you are (as in "Comcast in Cincinnati), what your measured download speeds have been, whether you noticed this speed difference as between two wired connections or between wireless and wired, and anything else you can come up with, and we'll try to help you sort it all out.

Again, welcome to our forums!

[rrsears]

Thanks a lot for your response! My ISP is Cox in Phoenix, AZ. I have the package that's supposed to get between 20-25 Mbps. After I installed a DOCSIS 3.0 modem I was getting between 17-20 (not bad, generally). When I unplugged the router and put the ethernet cable directly into the computer, I go 31Mbps! That's why I thought a new Airport Extreme with Gigabit Ethernet connections would help. The modem's Link light showed Orange which indicates a 10/100 connection (from the old Extreme) and showed Blue when connected to the computer (which indicates a Gigabit connection and is bonded according to the instructions). Thanks for you help.

Rick

[mduell]

Try a few more speed tests both ways to see if it's a real difference or a one-off. You don't need to buy gigabit to achieve 30Mbps, although the NAT performance of the old AEBS CPU may be holding you back.

Originally Posted by ghporter 

A true 10/100T system should get reasonable maximum throughput of up to 70Mbps (that's mega BITS per second), while a reasonable max throughput over an 802.11G wireless connection should be in the neighborhood of 35-40Mbps (again that's BITS).

Eh? It's routine to see 90+Mbps over 100BaseT, but you're not going to see better than 25Mbps over 802.11g.

[ghporter]

Originally Posted by mduell 

Eh? It's routine to see 90+Mbps over 100BaseT, but you're not going to see better than 25Mbps over 802.11g.

With an intermittent source, such as web page loading or modest file downloads, 70 seems to be a good number that most people can see on a regular basis. On a LAN, you can indeed get closer to 90+Mbps, but the fragmentary nature of Internet file transfers (and limitations of speed test tools that depend on Internet transfers) make 100BaseT look like it has a lot more overhead than it does.

I've gotten a good solid 40Mbps over WiFi G in ideal conditions. Transferring large files over my LAN goes pretty fast, with 40 being on the high side of what I've observed. This is based on what certain tools report (I think I was using iStat the last time I checked my WiFi throughput on my MBP).

No argument that my numbers weren't "typical," but I intentionally used "pessimistic" wired numbers and "optimistic" Wifi numbers in my above post to emphasize the magnitude of the difference between the two types of connections. Yes, I oversimplified.

[mduell]

Originally Posted by ghporter 

With an intermittent source, such as web page loading or modest file downloads, 70 seems to be a good number that most people can see on a regular basis. On a LAN, you can indeed get closer to 90+Mbps, but the fragmentary nature of Internet file transfers (and limitations of speed test tools that depend on Internet transfers) make 100BaseT look like it has a lot more overhead than it does.

That's . If your internet connection does better than 70-95Mbps with GigE locally, it will do the same with 100BT locally. But the op is pushing half this, so it's just a distraction here.

Originally Posted by ghporter 

I've gotten a good solid 40Mbps over WiFi G in ideal conditions. Transferring large files over my LAN goes pretty fast, with 40 being on the high side of what I've observed. This is based on what certain tools report (I think I was using iStat the last time I checked my WiFi throughput on my MBP).

Were you counting uncompressed bits with a compressed protocol? O'Reilly lays out the math for the ~27Mbps limit for TCP over 802.11g/a.

[ghporter]

Originally Posted by mduell 

That's . If your internet connection does better than 70-95Mbps with GigE locally, it will do the same with 100BT locally. But the op is pushing half this, so it's just a distraction here.

My broadband connection maxes out at 6Mbps downstream...and most consumer connections max out around 18-20Mbps; even OptimumOnline, which used to be "insanely fast" is limited to 15Mbps down, 2Mbps up. Since most consumers don't have full-blown fiber to their routers, I used the more common range of downstream speeds. My real-world connection gets just a bit over 5Mbps down with over 600kbps up (ATT DSL), while a friend's cable connection gets real world speeds of something like 12Mbps down with around 800k-1Mbps up.

Originally Posted by mduell 

Were you counting uncompressed bits with a compressed protocol? O'Reilly lays out the math for the ~27Mbps limit for TCP over 802.11g/a.

Compressed, obviously. Compression is critical to higher speeds with G. Otherwise you'd only "see" an improvement over B of about 12-15Mbps (which would have killed the marketing of G, I think).

[Snow-i]

Originally Posted by rrsears 

Thanks a lot for your response! My ISP is Cox in Phoenix, AZ. I have the package that's supposed to get between 20-25 Mbps. After I installed a DOCSIS 3.0 modem I was getting between 17-20 (not bad, generally). When I unplugged the router and put the ethernet cable directly into the computer, I go 31Mbps! That's why I thought a new Airport Extreme with Gigabit Ethernet connections would help. The modem's Link light showed Orange which indicates a 10/100 connection (from the old Extreme) and showed Blue when connected to the computer (which indicates a Gigabit connection and is bonded according to the instructions). Thanks for you help.

Rick

You don't need DOCSIS 3.0 for 25MBPS. Docsis 2.0 can handle practical throughputs of up to...uhh...memory fails....I want to say 35-40 Mbps, but definately more than 20-25. A new Extreme would certainly let you see those speeds.

I have a DOCSIS 3.0 surfboard with the latest gen AP extreme. My connection is supposed to be 50/20, and on ethernet and over 5ghz 802.11N I see those speeds. 20 Megs of upload speed is niiiiice :-).

BTW, I got my new AP extreme refurbed from Apple, and I couldn't be happier.

That said, its good that you've got a 3.0 modem, as ISPs are rapidly increasing max bandwidth to stay competitive.

[rrsears]

Thanks a lot. You've been a big help.

Rick