Upgrading my home network to Gigabit Ethernet and Wireless-N turns out slower than before

Question

My home network has three desktops, three laptops and some NAS drives. All desktops and NAS drives support Gigabit LAN and all laptops support Wireless-N. I was running a 100 BaseT switch though.

I recently purchased a Gigabit Ethernet Switch and an Wireless-N ADSL Modem-Router.

After upgrading, I noticed that the wireless file transfer speeds from laptop-to-NAS and vice versa became terribly slow. Possibly even slower than before the upgrade. The transfer speeds from desktop-to-NAS (wired) have improved though.

As an example, copying a 50GB file from laptop-to-NAS was estimated at 15 hours!

Is there something I can do to improve this? Also, should I consider buying a dedicated wireless access point for speed rather than using the Wireless modem-router?

UPDATE: Not sure if this helps but I noticed that all network cables installed in the network are CAT 5.

Answer 1

1. This sounds like a problem with your Wireless-N ADSL Router. Note that speeds rated for Wireless-N devices (like Wireless-G or other technologies) are theoretical maximums. The practical speed depends on the router hardware and firmware and are usually well below the theoretical maximums. You should try the wireless part with another (better rated) Wireless-N router.
2. Another thing to look at is if the Wireless-N router is configured to use WEP or WPA for security. Using either of these encryption mechanisms would force it to act like a Wireless-G router and thus bring it below 54Mbps. Make sure you're using WPA2.
3. Are you sure you don't have any non-802.11n devices? If there's a mix of N and G (or worse, B) devices, then the default setting on most routers to use a "Mixed" mode could affect the throughput for higher speed devices. If you can change it, set the Network Mode to "Wireless-N" and not to anything else.
4. You could also try changing the Channel configured for wireless. That would help if there's interference in your environment.
5. Check if the router firmware is the latest and upgrade if necessary.
6. Also check the Cisco forums. It looks like you're not alone with speed issues.
7. Since the desktop speeds have improved, the Gigabit switch is helping the wired connections. However, CAT 5 may not be sufficient to support Gigabit ethernet speeds. You'd likely get a much better speed between your desktops and NAS through the wired connection with a CAT 6 cable (it's certified for Gigabit ethernet). A cheaper alternative to CAT 6 is CAT 5e. To improve speeds even further on the wired network, you can configure your systems to use Gigabit full duplex with Jumbo Frames (assuming all of them support it). The default configuration would be to auto-negotiate the speed and use Standard Ethernet Frames.

Also see:
CAT 6 VS. CAT 5e