Wireless Network Throughput Problem

[GregBester]

Hi guys,

I have a home network problem that is baffling me. I bought a Belkin N150 modem/router that supports 802.11b, g, and n devices and has a maximum link speed of 150Mbps. The reason why I bought it initially was that the internet package I opted for only came with a wired router and because I wanted to make my home network wireless. On top of that I was hoping to continue enjoying wireless media streaming, which has worked great via ad-hoc between my two laptops, both which only support up to 54Mbps as they only have [up to] 802.11g integrated NIC devices.

For the last couple of years or so, I have had no trouble streaming video between laptops and even added a third desktop PC later on, bridged to one of the laptops (computer to computer) via normal ethernet. I could access all hard drives in every computer, and stream video between all of them with no problems. It's probably relevant to note that most of the video I watch is ecoded to 1 to 1.5Mbps and mostly mp4, mpeg, and avi so it's nothing HD and therefore shouldn't tax the network too much.

Anyway, I bought this Belkin 150N and thought that it would improve network streaming performance while offering me wireless internet as well. Alas, it does not.

When streaming video from one machine to the other, the video keeps buffering, freezing and glitching. Or at least it seems like that's what it's doing. To keep the process simple, here is the current setup I am trying to get working:

MEDIA LAPTOP ---/wireless/---> ROUTER ---/ethernet/---> DESKTOP PC

When I try and copy a file from the media laptop (on 802.11g) to the desktop PC via the router, I get a maximum transfer speed of 2.2 MB/sec. A decent sized movie file of 800MB comes in at about 6 min to transfer. I realise connecting a G device to an N router is going to affect the router's performance and 2.2MB/sec is probably typical performance.

So my question is, if a whole movie takes 6min to transfer, why does streaming get interrupted and glitch out, as if it's running out of bandwidth?


More info.

I downloaded NetMeter to monitor network activity when copying and streaming, etc. There is a screenshot of it attached to this post.

In the purple oval on the left you can see that I am getting maximum transfer speeds allowable by the 802.11g standard when copying files across the network. On the right, in the yellow oval, you can see the activity that is recorded when I attempted to stream a video. As you can see, maximum bandwidth is not even being approached, I assume reflected by each spike for when the media player (VLC) buffers the video (I assume). Then the video stops streaming unexpectedly. WHY??????

The router and the media laptop are in the same room and have line of sight. Is it just my router? Should I get a 300Mbps one?

If anyone has a solution or any insight to this problem, please please help!

Cheers

 

[thiggins]

Windows file copy has optimizations built in to ensure reliable and fast data transfer. Filecopy uses TCP/IP, which will retransmit data if it is lost.

Videos are encoded using variable bit rates and will be pulled across the network by the player if you simply browse to the file and open it.

This is why you see a consistently high bandwidth during file copy and a variable one during video play.

Most video players (VLC included) are not intelligent and don't buffer. So when they encounter more errors than they can handle during playback, they simply stop. Things like Hulu, Netflix and any web-based streaming service are much smarter and use protocols optimized for dealing with low bandwidth, high variability link as well as copious buffering. I'll bet viewing web video works fine. You can run Netmeter during a video stream session and see what the bit rates look like.

2.2 MB/s is ~16 Mbps, which is a typical 802.11g speed with a strong signal. What I suspect is biting you is throughput variability over the longer time period it takes you to view a video. 802.11n routers typically have a much higher throughput variability due to higher packet loss. This doesn't bother non time-sensitive things like web browsing, file transfer, email, but make video streaming a pretty miserable experience.

I'd first try forcing the router to 802.11g mode and see if that helps. Then I'd try another router. Let me know how you make out.

 

[stevech]

I'd also suggest choosing a different WiFi channel on your router, either 1, 6 or 11. This would be the case where a neighbor's WiFi, or some other radio frequency device's competition for the part of 2.4GHz you're set to use, is causing intermittent delays. As Tim said, these can accumulate and cause streaming to falter, whereas a file transfer simply retries to correct.

IMO: Streaming video on WiFi is always problematic. Best to use cat5, MoCA or HPNA (IP over power wiring). Or use 5.8GHz as its less crowded.

 

[GregBester]

Hi guys and thanks for the replies.

Before I saw your posts I did exactly what you both said, i.e. changed the channel on the router and forced it to receive only "g" signals. I also configured the integrated NIC's on both my laptops the same way and enabled throughput optimization and set them to transmit at maximum power.

I was able to stream video without any glitches last night but found that when I used the microwave or had my 3G modem plugged in, transfer rates still suffered. This is something I'm willing to live with, though. I'm just glad I got it to work.

@ thiggins, thanks for the insight into copying vs. streaming. That totally makes sense.

Truth be told, during this whole debacle it dawned on me that all these issues could be relieved if media player developers would implement some sort of smart buffering. Surely this would be a better idea? It would certainly give people more of an incentive to use their products. I like VLC because it plays anything and is simply PACKED with options. I just wish it buffered intelligently. Come on VideoLAN!

And thiggins, do you know of any media players that do implement this sort of intelligent buffering? I looked up Hulu and Netflix, but they are both web-streaming sites and not available in my country.

Another question is, how do I configure my router for 5.8Ghz? Doesn't it have to be dual-band to have this feature? I don't think mine has the option. All I get is 20Mhz and 20/40Mhz options along with which standard to accept.

Thanks for the help, guys. I think I'm sorted for now.

Cheers