AV CableLAN Performance

Even though both products are based on the same core technology, the electrical environments they operate in , i.e. coax and unshielded twisted pair, are very different. As a result, I had significantly different results from my testing.

In each case, I first did some preliminary testing with a pair of each of the devices connected back to back via short lengths of coax or telephone cable to get a feel for the best-case performance, and then connected them into my home's cable TV or phone wiring. I used IxChariot and ran TCP throughput and UDP streaming tests on both devices. Throughput was tested with IxChariot's throughput.scr script with the only change from defaults being a 200,000 Byte test file size instead of the default 100,000.

Since one of the target applications for these devices is to support the IPTV (streaming video), I also did some streaming tests. Qcheck can handle only a 1Mbps UDP stream - hardly fast enough for streaming video, so I again turned to IxChariot. I chose the IPTVv.scr script, which emulates a Cisco IP/TV Media server streaming an MPEG-encoded video file. The defaults for the script have it streaming at 1.451Mbps, but I pushed that to 10Mbps - attempting to emulate a data rate closer to that of a compressed HDTV stream. And since alternative networking makers like to tout how their products can support multiple video streams, I set up the test run two streams, one transmit and one receive from the machine running the IxChariot console.

Figure 5 shows average throughput 3.5 to 4 X higher than the 5Mbps I measured with Corinex' original HomePlug 1.0-based CableLAN product. But you can also see significant throughput variation for both transmit and receive streams - hardly what you'd want for time sensitive applications like streaming video.

Figure 5: AV CableLAN TCP throughput
(click on image for a larger view)

Figure 6 shows the UDP streaming test throughput results, which came out nicely. Throughput in both directions comes in pretty much at the 10Mbps stream rate. Lost data (not shown) is negligible, with small blips below 1% loss near the beginning and end of the run,

Figure 6: AV CableLAN UDP streaming throughput
(click on image for a larger view)

It's important to note that all the AV CableLAN tests shown above were taken with the adapters connected via about 100 feet of RG-6 coax that had no cable TV signals on it and no splitters in the run. And since I don't have cable modem service, I wasn't able to see whether using the AV CableLAN system with it degraded performance. So these results can probably be interpreted as representative of best case performance.