Macs With Airport Wireless Cards And My D-link Router


My Mac mini just arrived and has an AirPort Extreme wireless card. I have a cable modem connected to a D-Link 624 wireless router, which is connected through ethernet to my Power Mac G4 (running Mac OS X 10.3.9). I also have a Dell PC running Windows XP SP2 with a Dell TrueMobile USB2.0 wireless card. My Power Mac and the Dell receive the internet fine. I never have any problems and speed is fast and good. I set up the Mac mini yesterday and noticed that during long downloads, the download would just stop. The download rate would drop constantly until it hit zero KB/s (although as soon as it started to drop, no new KBs were downloaded). The Mac mini is running Mac OS X 10.4.2 with all of the latest software updates (every computer in my house is up-to-date, including the router's firmware). It seems that 80% of the time a 15+MB download will not complete. I tinkered around with my router settings but still I have not found anything to change that percentage to zero. I just thought to experiment with the AirPort (not Extreme) card in my Power Mac G4. My Power Mac G4 is connected through ethernet to the wireless router, but I still have the AirPort card in from when a friend gave it to me for free. I disconnected the ethernet cable and connected using AirPort. The Power Mac G4 and wireless router are about four feet apart (a monitor is between them) and the Signal Level is constantly between fourteen and fifteen bars (out of fifteen) in Internet Connect. The Mac mini is about thirty-five feet away from the wireless router (it is in another room down the hall), with three walls between them as well. I get between ten and twelve bars out of fifteen total (Interference Robustness is enabled, although when it is disabled, it still connects with the same signal strength). The Dell PC is a floor below me, about twenty-five feet away. Windows XP says the signal strength is "Excellent."

Continuing, the problems I had with my Mac mini and its AirPort Extreme card also happen with my Power Mac G4 when I use the AirPort (standard) card to connect to my D-Link wireless router. The success rate is greater with the router's neighboring Power Mac G4, so I want to think distance is a factor, although the ten-to-twelve bar Signal Level (which is very good) seems to disprove that.

I will be happy to explain my router configuration if it will help. I don't have any fancy features turned on (after experimenting with Super G and Turbo modes, I decided to leave them off), and I'm broadcasting on Channel 11 (which is the best channel? I can select between 1 and 11.

I appreciate everyone's eager help and patience as I deal with this problem. Just to let you all know, I try a lot of tinkering before I report a new problem, so know that I'm not just typing these posts up at every whim. I hope you will help me with my wireless internet problems.

That being typed, I have a few more things to share: whenever a download stops and goes through that constantly-decreasing-KB/s act, both Internet Connect and the Network Preference Pane list my AirPort connection as connected and never show a drop of any kind.

Also, the D-Link Knowledge Base says this…
"Wireless Drops With Large File Transfers:
If your wireless connection is dropping with large file transfers or downloads, please change the preamble to short on the card and the access point/wireless router. Consult the documentation that came with your wireless card and access point/wireless router for help with changing the preamble. This will allow for better connectivity on busy networks."
Upon checking, "Short Preamble" was (and always has been) enabled, as opposed to "Long Preamble."

I will be happy to answer any questions that will help you help me. Thank you very much and have a nice day!
I have almost the same setup, and am experiencing the same problem. On an IRC channel I frequent, the guys there seem to think that is the physical pipes between ISPs in between my computer and the one I am downoading from, and not a problem with the computer setup at all. They kind of say 'oh well, move on...' to me.