USB ethernet adaptater blocked at 100Mbps

Discussion in 'MacBook Air' started by Mr Eddy, Sep 8, 2011.

  1. Mr Eddy macrumors newbie

    Jul 26, 2011

    I've bought two usb ethernet adaptater, first one looks like the monoprice one :
    And the other one is the Belkin F5D5005.
    The first one wasn't coming (I leave in France and bought it on ebay), that's why I've got two know, but I'm about to ship bakc one of them.

    Anyway, my problem is I get the exact same speed transfer with bot, and the Belkin has a light to indicate if it's running 100Mbps of Gigabit, and it says it's blocked in 100Mbps.

    I've tested some transfer from my NAS (Synology DS211J), ans speed is around 11-12MB/s, never better. Indeed, I had the same speed with the Apple adaptater. And sometimes, it's even blocked at 10Mbps instead of 100Mbps... I had to plug/unplug them to get it back to 100.

    I've been using ASIX AX88772 drivers (without them, Lion couldn't even us the adaptater).

    Any idea what I could check to see what going on and manage to have a semi-Gigabit (the USB maximum speed indeed) ?

    Thanks :)

  2. miles01110 macrumors Core


    Jul 24, 2006
    The Ivory Tower (I'm not coming down)
    Somewhere in your network you must have a 100Base-T bottleneck, which explains why your maximum speed is 100 Mbps = ~12 MB/s. You probably won't get any better than that.
  3. Azathoth, Sep 8, 2011
    Last edited: Sep 8, 2011

    Azathoth macrumors 6502a

    Sep 16, 2009
    AFAIK there is no Ethernet to USB (2.0) adapter that does more than 100Mbps ethernet (= ca. 11MBps). The only Ethernet standards are 10Mbps, 100Mbps and 1000Mbps (and up). USB 2.0 can't handle 1000Mbps, and unless some bridging is going on, I would expect the speed to be capped at the next lowest level - e.g. 100Mbps

    ASIX chipset lists that 1000Mbps is MAC (no, not Apple Mac) only - ie. there is no 1Gbps PHY on the chipset.
  4. Mr Eddy thread starter macrumors newbie

    Jul 26, 2011
    Miles01110 > The MBA is connected to a modem/routeur which is connected to the NAS. So I can't see any bottleneck in my configuration which is really a simple one.

    Azathoth > USB are limited to 480Mbps, and I've read review here and on some other website of user reviewing adaptaters with which they could get real 250-300Mbps.

    Any other idea ?
  5. deeddawg macrumors 604

    Jun 14, 2010
    Are you getting higher speeds from other devices on the network? What's the brand / model of the router?

    What's the rating on the network cables you're using? Cat 5, 5e, 6?
  6. Mr Eddy thread starter macrumors newbie

    Jul 26, 2011
    Unfortunately my MBA is my only computer at this time.
    I'll try a test with the white macbook from a friend to compare them tomorrow.

    The modem is from my internet provider. The brand is netgear, I'll check this too tonight.

    The cable are the one provided with each device (modem and NAS), how can I know their category ?
  7. deeddawg macrumors 604

    Jun 14, 2010
    If you have cable internet, then I think the likely Netgear units are the CMD31T or CGD24N.

    If your provider gave you the CGD24N then the problem is the router; the CGD24N doesn't appear to support gigabit ethernet; 10/100 only, which would create the situation you're seeing.

    Post the model number and someone here will look it up to see if it supports gigabit ethernet.

    Ethernet cables often have lettering printed on the cable which will state if they're Cat 5, 5e, or 6. If there's no lettering, then I'm unsure of a way to tell. I wouldn't worry about the cables so much at this point as the router.
  8. crspechicn macrumors newbie

    Jan 3, 2011
    What Azathoth is saying is that there is no "480 Mbps" ethernet standard -- you're either at 100 Mbps or 1000 Mbps (gigabit), best case scenario. While a regular USB drive or other peripheral could theoretically use up to 480 Mbps, the ethernet standards are such that you are either operating at 100 Mbps or 1000 Mbps, which is a hardware (PHY) function.

    Do you have links to other reviews of USB-ethernet adapters where people are getting > 100 Mbps? Perhaps theirs have 1000 Mbps capability but just can't use it all.
  9. deeddawg macrumors 604

    Jun 14, 2010
    See the Lev Walkin review on Amazon. Claims to have achieved 20-30+ megabytes per second sustained transfer speeds, which would require >100Mbps.

    It stands to reason that you can use gigabit ethernet on devices that can't feed the full 1000Mbps through; otherwise you couldn't use 802.11n wireless routers with gigabit ethernet devices, since 802.11n won't support 1000Mbps throughput. I'm no ethernet guru, but I expect there's capability to buffer and throttle packet throughput if the gigabit port is feeding data faster than the host can deal with it.

    Point being that a USB gigabit ethernet adapter certainly won't give full gigabit throughput due to USB port limitations; but it should be possible to see throughput well in excess of 100Mbps Fast Ethernet.
  10. Mr Eddy thread starter macrumors newbie

    Jul 26, 2011
    A big thanks, with your help I've been able to find out were was my problem.
    The modem/router is a CBVG834G (here it is : ) And it sucks... Network is limited at 10/100Mbps. And the ethernet cable they rovide is a Cat 5, which makes sense since the modem can go any quicker.
    I was naïve thinking they would provide 10/100/1000baseT by default and didn't check this in first place.

    And I've discovered another specification of my modem, it's 802.11g and not n for wireless. It has nothing to do with this topic, but I got it 7 months ago, so I assumed it was capable of "n" WiFi.

    My conclusion is simple, I'm gonna get a router with "n" WiFi AND gigabit support.

    So if you have any advice :) I'm gonna search around the forum anyway.

    Lev Walkin's review is the one which made me buy my adapter indeed.

    I'm not wondering to get real gigabit, just looking for a better speed than 100Mbps. I exchange lots of data between my NAS and my MBA, since there are some RAW photos in there, more speed would be helpful when exporting them via Lightroom for example. This was my point crspechicn, sorry if I wasn't really clear in first place.

    While keep you updated when I get a good wifi/router. Don't know if I can expect a better speed for the wifi (MBA has a "n" Wifi which isn't a full "n" I read), but I'll surely get better transfers for local network.
  11. billy12 macrumors member

    Apr 16, 2008
    If you're looking for a new router, I recommend the Linksys E4200; it's one of the best consumer routers. It does simultaneous 2.4 GHz and 5 GHz 802.11n and has four Gigabit Ethernet ports. It uses a Broadcom chipset, so it's compatible with DD-WRT and Tomato firmware (though 5 GHz isn't yet supported by all firmwares). On the pricey side though.
  12. deeddawg macrumors 604

    Jun 14, 2010
    Glad we were able to help sort out the cause of the problem.

    First thought is to see if your internet provider can swap you out for something like the CG3000. If they'll do that for low/no cost to you, then you benefit from gigabit ethernet plus 802.11n wifi with the provider providing support for the device.

    If they want to charge you a small fortune, then you might consider adding your own wifi router such as the WNDR3700 or WNDR4000. The challenge is you'd be adding a 2nd layer between your network and the WAN, which complicates debugging any connection issues, as well as complicating setup and any routing you might want to do to gain external access to your Mac or Synology NAS. You'd probably want to turn off wifi on the CBVG834G. This is probably not the best solution for people not savvy about networking and router configuration.

    A third solution is to add a gigabit switch to the existing router; connect it to the router with one port, then use two other ports for the Synology NAS and Mac's USB ethernet adapter. Simple, but big downside is you're stuck at 802.11g wifi speeds when you're accessing the Synology over wifi.
  13. Mr Eddy, Sep 10, 2011
    Last edited: Sep 10, 2011

    Mr Eddy thread starter macrumors newbie

    Jul 26, 2011
    Unfortunately, in France, each ISP provides one type of modem and you don't have any other choice. And they check the MAC address of the device, so even if I wanted, I couldn't do it.... So the CG3000 is out of question unfortunately.

    I've bought on Amazon the TP-Link WR1043ND, even if the Linksys E4200 and Netgear WNDR3700 and WNDR4000 sounds good, their prices are a bit too expensive I thought.
    And as you said, now I'm facing this challenge with the 2nd layer it adds...

    Here is my setup :
    Internet <--> Netgear CBVG834G <--> TP-Link (on one of the 4 LAN ports)
    My NAS Synology is connected to a LAN ports too. The MBA is connected via the WiFi of TP-Link (I have to buy another cable to use it with the LAN port, but I'm stuck with some configuration problem)

    I disabled DHCP, configured LAN to static IP in the same subnet than what the Netgear provides (here, In this configuration, I can access internet from TP-Link's wifi or by connecting the mac to the TP-Link on a LAN port, both works perfectly and WiFi access speeds is now 3 times faster than with my Netgear.

    I can also access my NAS when I'm in the local network (and again, via WiFi, access to my iTunes library which is on the NAS is much better). But from on outside one, I can't reach it... Do I have to setup some port triggering or virtual servers in the "forwarding" menu of the router ? I tried both, and didn't change anything.

    Or did I missed something else to configure ?

    EDIT : Maybe it has nothing to do with my setup. I plugged my NAS again to the Netgear and it's impossible to access from outside the local network, although I didn't changed anything in it's configuration or in the Netgear modem configuration (juste re-enabled wifi for my test)
    I haven't needed to access it from outside since a week or so, that's why I didn't realize this before.
    Since all the needed ports or open, the IP address of the NAS is set to static, I really don't know what to do know.... a network device unaccessible from network, sounds like useless :/
  14. crspechicn macrumors newbie

    Jan 3, 2011
    You can spoof MAC addresses with almost any good router, at least I know you can with Linksys/Cisco routers. I believe that functionality is there exactly for that reason. Google "MAC Cloning" or similar.

    You have to setup "Port Forwarding" not necessarily port triggering, but port triggering will do the job if you have it setup right. Do you have dynamic DNS setup? Are you certain of your external IP?
  15. Mr Eddy thread starter macrumors newbie

    Jul 26, 2011
    My TP-Link provides a "MAC clone" thing, but it's made to clone PC's address on the WAN port. Not sure this is what you were thinking of.
    In the forwarding menu, all I have is :
    Virtual servers
    Port triggering

    For the external address, I'm sure of it since I was able to access netgear web administration from it (a functionality that is provided by the web administration, all I had to do is activate it to use it)

    I'll try again all this from start when I get back from work. But there's something going wrong with this net gear modem :/
  16. 2IS macrumors 68030

    Jan 9, 2011
    I'm running this router and I've been very pleased with it. Best router I've owned and I've owned many. About the only thing I am not terribly impressed with is it's 5GHz range, which is pretty short. I'd stay way from DDWRT for this router. 5GHz doesn't work properly and overall performance is worse. Not sure if Tomato is any better. I've just kept mine stock for now.
  17. billy12 macrumors member

    Apr 16, 2008
    I'm on stock too. Haven't found any Tomato builds that support 5GHz yet.
  18. Azathoth macrumors 6502a

    Sep 16, 2009
    I'm also on the E4200 - my first 'n' 5GHz router. The 5GHz range isn't great, but OTOH mush less interference from other users.

    AFAIK Apple doesn't support 40MHz BW on 2,45GHz - hence for max data rate you should use the 5GHz band.

    I get 80-100Mbps data throughput when I'm near the router.

    The only minus on the router is the limited logs that are available from it.
  19. AlecEdworthy macrumors 6502


    May 1, 2007
    Leicestershire, UK
    It is possible that your ISP has locked down the admin interface on the router. I found an instruction manual on the web for your model of router and it says on page 1-7 that you can alter the access privileges for two different levels of user (MSO and Admin) and then on page 3-10 it discusses port forwarding (which is what you will need to use). You'll need to know the IP address of your NAS and the port number you need to forward (e.g. 548/tcp for AFP) in order to configure that.


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