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Streaming DivX/Xvid/Video_TS from PC to Mac with WRT54GS v4

Discussion in 'Cisco/Linksys Wireless Routers' started by Fedorov, Feb 14, 2006.

  1. Fedorov

    Fedorov Network Guru Member

    Hi all,

    Sorry for the long post, thought I'd at least explain what I've tried so far and hope you Linksys experts can offer me some good advice...

    I decided the Mac Mini was the perfect/quiet/small size to use in the living room as a media centre for my Plasma TV.

    Apart from surfing, my main requirement is to watch downloaded US tv episodes etc... I usually download all these to my PC and I've got them in a shared folder which I can access on the Mac Mini.

    So far, whether it is a 700mb Xvid or (more extreme?) Video_TS folder on my PC's hard drive if I try to play them on the Mac with VLC Media Player I get the video/sound freezing briefly every 5-10 seconds, not really watchable.

    My PC *was* wired to a Belkin WirelessG Highspeed Router, after looking at firmware issues I noticed that this model has a lot of "packet loss" issues reported and while it's never been an issue for my 2 wired PCs or wireless PocketPC something is causing this freezing issue to the Mac.

    Note that I tried copying one of the 700mb Xvid files across to the Mac and it froze while 10% through copying, it actually needed a reboot of the Mac!
    Transferring LARGE files wirelessly I know can also be a problem with many routers/firmware...

    My friend has a Belkin Pre-N router and his streaming to his Mac Mini appears much smoother even though I possibly have a better signal strength to my Mac.

    So, as my Belkin router is the older v1000 hardware I decided it was worthwhile getting a newer model... staying away from the ghastly unstable v5 firmware Linksys I got a Linksys WRT54GS v4 firmware model yesterday which comes with 1.05.03 firmware on it...

    Tried streaming a movie to the Mac again, I've got slightly less freezing but it still does it way too often to be watchable.

    I've now tried copying a large 700mb file across and that now works okay with the Linksys :)

    So my question is... is anyone else streaming video to their mac wirelessly? is it smooth? what suggestions has anyone got so I can achieve my dream? Smile
    Is it even possible to stream this stuff smoothly through the airwaves???

    Thanks in advance to you all.

    Fedorov.
     
  2. dvaskelis

    dvaskelis Network Guru Member

    I stream from my Mac (wired) to my laptop (wireless) and vice-versa all the time without issue, including streaming to a wirelessly-bridged Elgato EyeHome. Here's some hints I'd posted on hyperwrt.org to maximize wireless performance, some of which assume you're using a recent flavor of HyperWRT in your router:

    Well, you won't get faster than your wired speed, but maybe you can get pretty close. 802.11g under the very best circumstances, between one access point and one client sitting closeby, can get to about 22Mbps-24Mbps, although can be tweaked a bit to around 26Mbps-27Mbps with frame bursting or even up to 34Mbps or more with SpeedBooster (125 High Speed Mode). Sounds like a marketing blurb, huh?

    Note the "very best circumstances." Some things to try and get as close as possible to those best circumstances:

    1. Eliminate all interference from neighboring wireless networks

    You can use the Site Survey in the latest tofu (WRT54G/GL) and Thibor (WRT54GS) builds of HyperWRT to see what nearby networks your router can "hear". First see if you can find a clear channel. If there's no clear channel, click on RSSI to sort by weakest signal (largest absolute value dBm) to strongest signals (smallest absolute value dBm), and see if you can identify the clearest channel with the weakest signal and least interference.

    Now, keep in mind that the specifications for 802.11g set a frequency channel at the center of its signal that also "bleeds" into nearby channels. That "bleed" is +/-2 channels for 802.11b/g! That means an AP on channel 1 will send some of its signals on channels 2 and 3 and some below channel 1. An AP on channel 6 will send some of its signal on channels 4, 5, 7 and 8. And an AP on channel 11 will send some of its signal on channels 9, 10, 12 and 13. So when choosing a channel to reduce interference, be mindful of the bleed.

    It can be tougher if devices have turned up their signal strength to be high-powered beyond spec, so that it interferes with even more than two channels on either side and you won't know except for the hit in performance. Also, Atheros-based (Super G) and Airgo-based (True MIMO) APs can use so-called "channel bonding", where they can take over all of the channels by doubling the transmit power on channel 6 and "bleeding" over all channels from 1-11! Ah, who really likes their neighbors anyway?

    Also, sneaking into neighbors homes and turning off their wireless networks so you can download porn faster is typically frowned upon.

    2. Eliminate all other interference

    2.4GHz interference is all over the place: other neighboring wireless networks, cordless phones, BlueTooth devices, microwave ovens, baby monitors, etc. These can all reduce the speeds of your wireless networks.

    In extreme cases, you might want to think about reflectors to block interference, either from neighboring networks or other 2.4GHz devices.

    3. Drop 802.11b support, run in G-Only mode

    Set your router for G-Only in Basic Wireless Settings for its wireless network mode, as 802.11b devices can decrease the overall performance of the wireless network. Yes, that includes your shiny new 802.11b-only Sony PSP. Ah, well, maybe you can live with Mixed mode? :)

    4. Have the fewest wireless devices you can get away with

    The more wireless devices you have, the worse your performance will become. Can you consolidate any of them by wiring them to a wireless bridge?

    5. Use no encryption or WPA-AES

    Linksys WRT54G/GL/GS routers (and most Broadcom-based products) run their fastest with wireless security disabled, although they do AES in hardware so WPA-AES can be very close to the speed of no encryption. Using WEP will cost you about 10% performance, and WPA-TKIP will cost you about 17%.

    Note that older devices may only support WEP. This may give you the excuse to replace them and see what they're worth on eBay!

    6. Tweak 802.11g

    In Advanced Wireless Settings, make sure you have Frame Burst Enabled. It can make a difference, sometimes up to 20%, and it technically fits within the 802.11g standard although it's not explicitly in the standard. You can also set the Preamble to Short, although the difference that can make is very, very small and it can cause problems for fussier clients... my old WGA54G couldn't work with it for example. Also, if you have 125HSM clients and a WRT54GS, make sure you have Afterburner (SpeedBooster/125HSM) set to Auto. That can add another 15-20% in performance over just frame bursting, but your mileage may vary. It's a proprietary Broadcom approach to fast frames and hardware compression that works best when there are very few clients at shorter distances/good signal strength, and can actually make things slower if there are many clients or distances are long.

    To my knowledge, there is no support for 125HSM (SpeedBooster) in the Airport Extreme drivers in OS X.

    7. Stay strong

    The closer to the AP, the stronger the signal, the faster the performance. As you get further away, or start to weaken the signal with walls, the slower it will be.

    Try a high gain antenna on both sides of the equation if you need to boost a weaker signal. Note that high gain antennas do not cause additional interference. They work without increasing the power of the signal beyond spec, think of them as making signals clearer and more sensitive to signals.

    In the worst-case scenario, you can up the transmit power on the Advanced Wireless Settings page, although usually with increased noise and more interference to neighboring channels, so it may actually hurt performance although may improve range.

    Soon enough we'll all be running 802.11n networks with MIMO and today's 802.11g performance will be long forgotten. Anyone remember tweaking a Hayes Smartmodem 1200 thinking "holy sh** that's fast!"? Or the speed of Courier HST making you fall out of your chair? Progress is good.

    Good luck. Please post any results.
     
  3. Fedorov

    Fedorov Network Guru Member

    What a great reply, thanks a lot, going to divulge all of that information.

    One thing I did try last night was to turn the WRT54GS firewall off, turn mac filtering off, turn encryption off, turn g-mode ON but still got the same random freezing when streaming to my mac.

    I've not dared to flash to HyperWRT yet, keep seeing too many postings on here and other forums about how much harder the WRT54GS V4 is compared to the V3 etc....!!! If anyone has got a "definitive" guide to getting my V4 to upgrade the firmware then I'll be happy to try it ;)

    Thanks again, plenty of things to try still...

    Fedorov.
     
  4. dvaskelis

    dvaskelis Network Guru Member

    Thibor has a version specifically for the GS v4.0 that can be loaded directly by the stock Linksys firmware.
     
  5. Fedorov

    Fedorov Network Guru Member

    I bit the bullet and flashed from my original 1.05.03 firmware to Thibor's 13d GSv4 specific build - all worked fine :)

    Tried the site survey and it turns out that the one and only router it sees is a Belkin54g nearby on channel 11, the same channel as I was using.

    I switched to channel 1, tried streaming but still got the freezing issue... more to try still..... :)

    Fedorov.
     
  6. Fedorov

    Fedorov Network Guru Member

    Update: I stumbled upon a thread over on the VLC media player forums where others were having Xvid freezing/choppiness... there is a setting in VLC to change the size of the buffer cache - it uses a very small one by default (300). Setting it to something above 2000 cured my problem. Some other Xvid's I tried I needed to increase it to 6000.

    Haven't seen any freezing in any of the clips I've tried since! :)

    Thanks again for all the suggestions, glad it turns out to be a VLC issue rather than a PC/router/Mac hardware issue :)

    Fedorov.
     

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