Sunday, July 04, 2010

DD-WRT Wireless Router Won't Respond

I have a Linksys WRT54G V8 wireless router that I installed "DD-WRT v24-sp2 (10/10/09) micro". This router is pretty limited in the memory department (only 8MB) which means even running the micro release can cause issues: slow network performance, unable to connect to the web interface, losing wireless connectivity and complete loss of network activity from the device. The only quick solution is to reboot the unit by pulling the power for 10 secs. So here are my tips on how to keep the WRT54G V8 running like a champ:

  • Set the max connections to 512 (You can find this under Administration>Management menu)
  • Set the TCP/UDP timeout settings to 120 (found in the same menu)
  • Schedule the router to reboot nightly (Administration>Keep Alive menu)
  • - Ensure that you setup the Time Settings found at the bottom of the Setup>Basic Setup page
  • Disable DNSMasq for DNS (Setup>Basic Setup menu)
  • Disable all services except for DNSMasq (Services>Services menu)
  • Disable UPnP (NAT/QoS>UPnP menu)
  • Disable QoS (NAT/QoS>QoS menu)

With these settings, you should have a rock solid wireless router that keeps running 24/7.

Issues to be aware of: This setup will limit the number of connections that your network can handle. That means apps like P2P and online gaming may run into some issues. I would not suggest using this router to support more than 10 systems at once.

Sunday, March 01, 2009

Wireless speed low with full signal strength

I have a Buffalo WHR-HP-G54, running DD-WRT firmware (DD-WRT v24-sp1 (07/26/08) std - build 9994) and noticed that my Dell Latitude e6400 had a low wireless speed, even with a strong signal strength. I would connect to my wireless network at 54mbps, and it would fall down to 36mbps, 10mbps and finally 1mbps. After some checking around, I was able to determine the settings that needed changing to fix the issue.

In the Wireless>Advanced Settings tab

TX Antenna: Left
RX Antenna: Left
Sensitivity Range (ACK Timing) : 0

After that, reboot the router and everything should be working fine. I now stay connected at 54mbps with my laptop.

The Dell has an Intel WiFi Link 5100 AGN card installed.

File synchronization

If you are looking for a fast and efficient to sync files between multiple machines, check out Dropbox . This service allows multiple users/machines to sync folders seemlessly (i.e. all done automatically in the background). It even uses the users file system, so you don't need to have change the way you load/save files.


Friday, August 24, 2007

Dual Core CPU issues

I upgraded my system to an Intel CoreDuo E6400 which is essentially two CPUs in one. Installed the CPU onto a new motherboard (Asus P5LD2) with 2GB of RAM and did a fresh install of Windows XP SP2. After the install, I did the full set of updates from Windows Update, which in theory would take care of all issues related to my system. I found later that what is needed is a

http://support.microsoft.com/default.aspx?scid=kb;en-us;896256

Read more from the Microsoft article.

Saturday, October 28, 2006

Wireless connection times out

I have two laptops at home, both with wireless cards that I use to connect to my router. It's a Siemens SpeedStream 6520 DSL Router w/ 4 ethernet ports and a 802.1G wireless access point built in. Once setup, the laptops would either loose the connection to the router, or the connection would time out (i.e. no traffic would go across the link and web pages would time out) every 3-4 minutes. After the 10th time, I had to find a solution. I was not surpised to find out that many other people had the same type of issue with this router (among other issues), but had a difficult time finding a solution.

After many attempts, I believe I have found a solution that holds up.

[Solution]

First off, you need to update the Router's firmware (for instrustions on this, refer to the manual). There is an auto-update feature within the web management interface. Secondly, update the drivers for your laptop's wireless adapters. This made a big difference with the overall stability of the connection. And finally, set the router to use 'Channel 2' instead of 10 or 11. This seems to operate on a frequency that is less prone to interference (at least it seems to be making a difference with this router).

[UPDATE]

Another issue with having your wireless connection drop out at random intervals is when your wirless router is configured to not broadcast it's SSID. I had set mine this way to avoid having others try to connect to my router, but then discovered that this setting was causing my laptop to drop it's connection to the router. By enabling the broadcast SSID, this resolved the issue and I have not had a dropped connection since.

[References]

Siemens 6520 Router Manual

Broadband Help Forum

Western Digital Second Generation Serial ATA hard drive not showing up at boot

I recentlty purchased a Western Digital 320GB SATA-2 harddrive, installed the drive to my second on-board ATA connector and to my suprise, the drive was not detected on boot. I currently have an Asus A7V880 Motherboard, which uses a VIA serial ATA controller. After some quick searching, I found the following on WD's support site:

Our Second Generation Serial ATA hard drives use autospeed negotiation. This enables our Second Generation Serial ATA hard drives to automatically detect the motherboard data transfer rate, making it backward compatible with First Generation Serial ATA data transfer rates. However, because this technology is so new, some older First Generation Serial ATA controllers are unable to support autospeed negotiation and cannot recognize the drive. This “drive not detected” condition occurs when a chipset is incapable of correctly negotiating the data transfer speed with a Second Generation Serial ATA hard drive.

[Resolution]

You need to set a jumped on the back of the drive. From the WD support site:

To lock the drive at 150 MB/s data transfer rate, install a jumper shunt on pins OPT1, shown in the picture below.


[References]

WD Support site

Friday, July 14, 2006

iPod keeps rebooting

I have a 10GB 2nd generation iPod, and after a good 3 years of constant use, one day it started to reboot in loop, never making it past the Apple logo. After a few hours of searching, I was able to locate the proper diagnostic keys to fix the issue:

1st, 2nd, and 3rd Generations
Reboot iPod: Hold down the menu and play buttons.
Disk Mode: Hold down the rewind and fast forward buttons after a reboot.
Diagnostic Mode: Hold Rewind, Fast Forward, and Select buttons after a reboot.

Mini, 4th, and Photo Generations
Reboot iPod: Hold down the menu and select buttons.
Disk Mode: Hold down the select and play buttons after a reboot.
Diagnostic Mode: Hold Rewind and Select buttons after a reboot.

After I got it into Diagnostic mode, I put it into 'USB Disk' mode in hopes that I could run the Apple iPod Updater software and restore it. After a few attempts, the Updater would run, and then give the error message "Can't unmount iPod". This was due to the fact that the 2nd generation of iPod's were not powered by USB. The solution? I had to connect the iPod via FireWire to my system, set it into Disk Mode and then run the Updater. After this, the Updater worked correctly and I was able to fix the rebooting loop.

[References]

iPod Lounge : http://www.ilounge.com/index.php/faqs/




Saturday, February 18, 2006

Spooler Sub system App issue

This was a weird one - on an WinXP system with an HP Laserjet USB printer, an error message started to pop-up constantly, with the following message:

Spooler Sub System App has encountered a problem and needs to close
Error signature
SZ AppName:Spoolsv.exe
SZ AppVer:5.1.2600.2696
SZ Mod Name: SD1MF32.DLL
SZ Mod Ver: 5.60.2209.0
offset:00004537

Quite annoyning - So, I went searching for a fix. Found one!

[Solution]

You need to remove all printers on your system. Un-install the printers on your system, then to clean any left overs.

Remove all files in the directory:

C:\WINDOWS\system32\spool\PRINTERS

Run regedit and remove all entries under this tree:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Print\Printers
Then, you simply re-install your printer drivers and all issues should be resolved.

Sunday, January 29, 2006

Bluetooth - On your laptop, handheld and beyond

For those of you who are starting to get into Bluetooth devices, say a new Bluetooth (BT) mouse or handheld PocketPC, you may quickly discover some of the short comings of these devices. Some of the issues you may encounter are inability to connect to the device, poor connectivity, and overall poor performance. I currently use a Dell Precision M60, IOGear Cordless BT Mouse, Sony Ericsson T637 and a Dell Axim v50 PocketPC - all of which rely on BT to communicate wirelessly. With a default setup, out of the box type of approach, connecting these devices was a touchy situation - if the device is able to be discovered, I would encounter poor performance/connectivity and typically not be able to re-connect the device in the future.

[Solution]

This solution isn't much of a 'magical fix' but more of a best practice. I'll go through each device:

Dell Precision M60 Laptop: With the Dell laptop, by default, you are using the Windows XP BT drivers (read: BT stack) and there in is the problem. The first thing I would suggest is to update the drivers via Dell's support site - in my case it was the Dell TrueMobile drivers. After installation there was a huge jump the connection quality and overall connectivity with my BT devices. I also disabled the power saving options for this device, so that Windows was unable to shut down the device, as I had problems with the BT device not coming back after I shut my laptop (putting it into standby mode)

IOGear BT Mouse: Simple - fresh batteries all the time. This little guy just needs juice - if you are getting poor performance, change (or recharge) the batteries

Sony Ericsson T637: This one was a bit more intensive and required that I update the firmware for the phone (which requires special hardware, called a Terminator). Check back later for a step by step on this.

Dell Axim v50 PocketPC: Again, by default, the drivers that ship with the Axim are less than satisfactory. You need to first update your devices ROM (I went from A01 to A09 - available from Dell's support site) which made a huge difference across the board. The next step is to install the necessary 3rd party BT drivers/stack for peripherals (such as a keyboard).

[Review]

To say that BT is a robust technology would be a stretch, but at least it's possible (with the right updated drivers) to get good use out of your BT devices.