450 K/s or less wireless throughput...

[rbivins]

Hello everyone,

I just upgraded my DirecTivo from the sleeper iso to the PTVUpgrade CD. Also added a new 120 GB A drive. My Tivo has really seemed to have settled down. I used to have all sorts of reboot problems and instabilities. I suspected the A drive, maybe I was right.

Well, 5 or six months back I was in a discussion with a few of you about why the Tivo throughput is so slow over a wireless network. Unfortunately, I don't remember the members that I was talking to. The gist is that I've attached my Tivo to my home network using two different wireless configurations, and they both get about the same throughput:

Config 1:
TiVo -> Wireless USB Adapter -> Wireless Access Point -> Network.

Config 2:
TiVo -> Ethernet (WIRED) USB Adapter -> Ethernet-to-Wireless Access Bridge -> Wireless Access Point -> Network.

The funny thing is that all my computers that are on the same side of the Bridge in Config 2 can talk to my TiVo at about 3,300+ K/s, but all computers accross the wireless side of the bridge talk to my TiVo at ~450 K/s, which is just a bit too slow for streaming.

Question is, what is it about TiVo data that makes it so hard to transmit wirelessly? It can't be the USB drivers, because they seem to talk at the 3,300+ rate that others have been able to consistenly acheive.

Just to add confusion to the problem, my PC's can talk accross the bridge at tremendous speeds (up to 4,000 k/s or even more -- it's a Wireless G network). The bridge is only about 15 feet away from the access point. It's just used to eliminate the wires acrooss the room (a comprimise mandated by my wife). All the other PC's in my house are wireless, and they talk at 108 Megabit using Netgear's XR technology, which the bridge doesn't use.

Anyway, at that long ago date, I remember someone saying that they had an idea on how to increase wireless throughput, but to check back in a while. I'm wondering if anyone has been able to improve the throughput in the interum?

I'd be happy with about 1,000 k/s just to be able to stream wirelessly. :)

Thanks, in advance.

--Robert

[Jamie]

Hello everyone,

I just upgraded my DirecTivo from the sleeper iso to the PTVUpgrade CD. Also added a new 120 GB A drive. My Tivo has really seemed to have settled down. I used to have all sorts of reboot problems and instabilities. I suspected the A drive, maybe I was right.

Well, 5 or six months back I was in a discussion with a few of you about why the Tivo throughput is so slow over a wireless network. Unfortunately, I don't remember the members that I was talking to. The gist is that I've attached my Tivo to my home network using two different wireless configurations, and they both get about the same throughput:

Config 1:
TiVo -> Wireless USB Adapter -> Wireless Access Point -> Network.

Config 2:
TiVo -> Ethernet (WIRED) USB Adapter -> Ethernet-to-Wireless Access Bridge -> Wireless Access Point -> Network.

The funny thing is that all my computers that are on the same side of the Bridge in Config 2 can talk to my TiVo at about 3,300+ K/s, but all computers accross the wireless side of the bridge talk to my TiVo at ~450 K/s, which is just a bit too slow for streaming.

Question is, what is it about TiVo data that makes it so hard to transmit wirelessly? It can't be the USB drivers, because they seem to talk at the 3,300+ rate that others have been able to consistenly acheive.It's got to be flow control or dropped packets. You could look into adjust the tcp window on each end (google "tcp window" for gobs of info). What version of the USB modules are you using? The newer versions of the usb 2.4.27 backport have a usbnet module that supports pause frame flow control. That might help.

Next step I'd take is to fire up ethereal on the receiving PC to look at what's going on over the wire.

All my tivos are wired, but I do have a wireless laptop and can stream SD shows to it no problem.

[rbivins]

It's got to be flow control or dropped packets. You could look into adjust the tcp window on each end (google "tcp window" for gobs of info). What version of the USB modules are you using? The newer versions of the usb 2.4.27 backport have a usbnet module that supports pause frame flow control. That might help.

Next step I'd take is to fire up ethereal on the receiving PC to look at what's going on over the wire.

All my tivos are wired, but I do have a wireless laptop and can stream SD shows to it no problem.

I can manually change the tcp window on my Wireless Access Point and on the bridge Receiver. Both are set to 1500, which is supposedly the "best" for the Windows environment. The PC's all seem to like it. I have no idea if this works well with TiVo packets.

It MUST be dropped packets, but I don't know why my Wireless network is dropping *only* the TiVo packets. I do believe I'm using the 2.4.27 backport drivers, but I do not know how to adjust the pause frame settings.

Have any ideas?

--Robert

[jonbig]

I can manually change the tcp window on my Wireless Access Point and on the bridge Receiver. Both are set to 1500, which is supposedly the "best" for the Windows environment. The PC's all seem to like it. I have no idea if this works well with TiVo packets.

Err, you're mixing your terminology. What you are referring to is the MTU (maximum transmission unit), not the TCP window. The TCP window settings only matter on the two endpoint computers that talk to each other (although the speed could be adversely affected by a lack of buffer space on bridges/routers and the like in between).

[rbivins]

Err, you're mixing your terminology. What you are referring to is the MTU (maximum transmission unit), not the TCP window. The TCP window settings only matter on the two endpoint computers that talk to each other (although the speed could be adversely affected by a lack of buffer space on bridges/routers and the like in between).

You are correct. I've probably got to figure out how to modify that setting. I think my problem is inefficiency of my wireless network coupled by the fact that the client I'm using is two Wi-Fi links from my TiVo:

Tivo -> USB Ethernet Adapter -> Ethernet-to-Wireless bridge -> Wireless Access Point -> Wireless PCI Network Card -> Laptop.

And, since these two links travel through one access point, whatever inefficiency is probably doubled.

The stream works real well if the laptop is in the same room as the Access Point and the Bridge. But, of course, the signal is loud when everything is in the same room. Plus, that sort of defeats the purpose of having WiFi in the first place.

--Robert