180Mhz CPU fast enough for 54MBit bridge?

[ramaza]

Hi,

I would like to use the Bullet5 with DFS and WPA enabled but I am afraid the 180MHZ Atheros SoC is simply not fast enough for handling a fully loaded 54MBit link with DFS and WPA. I don't need any firewall, traffic shaping, NAT or something else. Just a simple bridge.

Has anyone already tried this with AirOS or any other firmware?

Regards,
Franz

[WHT]

Comparing it to the $1,200 OsBridge 5GXt-HP with a 533 MHz processor, I don't think the $59 Bullet with a 133 MHz processor would meet your expectations.

[InoX]

If you need 50mbps TCP traffic use MIkrotik. For 15-25mbps use bullet..

[ramaza]

I only need 25mbps TCP traffic because I can't use 40MHz channels. I already use 533MHz XScale boards but the problem is that I have to detach the radios from the board. This is only possible with Ethernet or USB.

The Bullet5 meets exactely our requirements. Only the CPU could be too weak.

I would love using USB because the wireless drivers would work on the powerful XScale board and USB is self powering. But I don't know how much additional cpu load the USB stack generates. Also TCP/IP stack is quite CPU intensive.

Perhaps an optimized firmware could handle 25mbps and has enough head space for handling DFS with radar scanning. The problem is that I have to know for sure before starting special firmware development.

Perhaps also the Atheros driver could be offloaded over the ethernet connection from the MIPS processor to the XScale processor . Much the same like the GDI printers concept.

Of course this wouldn't work off the shelf but I have to look further and I would hire specialists for working on this project.

[broken]

in my opinion. 180MHZ clock is good enough for 25/25 in bridge mode. Linux kernel doesn't care any TCP/IP layer in bridge mode. Problem is in Offloading CPU by network card chipset. In models such as RTL8139 there is no offload in linux and windows drivers (is to cheap). But look at Intel Pro 10/100/1000 with Linux drivers - CPU Offload is excelent!

[ramaza]

The problem is that Bullet5 doesn't use Intel Pro LAN.

If I have to guess I would say Bullet5 / Atheros MIPS 4KC is like RTL8139 concerning the CPU load.

[dd-wrt]

Hi,

if you need 65mb/s throughput, take a look on dd-wrt + non 180mhz hardware.

[WHT]

Rconaway had some interesting results in another post.

Rory...correct me if I'm mistaken, but did you mention you had better results with a UBNT radio compared to an Osbridge. I think you posted it within the past week.

[mrapo]

osbridge handles packet load of 7000 per second or more while ubiquiti pretty much dies at 2000-2500 packets pers second.

so, how possibly is that better result?

[WHT]

I don't know for sure what Rory was talking about, that's why I was asking him to chime in here.

[rconaway]

Sorry guys, didn't get notice of this conversation for some reason. With the OSBridge stuff, you have to be more specific on which models.

We have tested and deployed OSBridge 5GXi's with 20 and 40MHz channels. With a 20MHz channel, the best we got in ftp transfer was about 20% less than an NS5 with the exact same setup, same computers, within 5 minutes of each other. At 40MHz, the differential got worse. I'm guessing it's a processor issue.

We also ran tests with SkyPilot and Belair just to get a further comparison. I have to say we were pretty disappointed in the Bel Air radios but we were running older firmware. We have since upgraded the firmware and it didn't get much better. I do know Bel Air told us to pound sand when we asked for upgraded firmware without a paid support agreement. You would think that at $10K for a mesh radio with a whopping 14dBi output on the backhaul radios you would get a little love. I'm guessing they would rather see these radios in my backroom than to have me actually deploy them. Nice job on their part. So instead of Bel Air radios adorning the spring training facilitiies for the Texas Rangers and Kansas City Royals, we put up Ubiquiti Bullets and NS radios.

Of course, this is the same mentality that keeps cities thinking they need to spend $150,000 per square mile.