On 28/05/13 08:26, Tony Langdon wrote:
Been having a bit of fun and games with ADSL since moving house. Have had the issue checked out, and other than some extra unused wiring in the house, which the Telstra tech disconnected, there are no known issues on the line. The Telstra tech's test unit can sync at nearly 4Mbps, and a Bigpond router (not sure what brand these are) will sync at 4.2 Mbps. However, I haven't had so much luck.
A loan Netcomm router from Internode was able to hold just under 3 Mbps, which was acceptable, however, that has since been returned. According to Internode, the line is 4.6km long, and I can expect 3-4 Mbps. What I'm looking for is a router that is known to work well on long lines. Doesn't need to be anything fancy, I will most likely put it into bridge mode and put the existing router behind it (which will give me VoIP, IPv6, etc). Just need something that can hold sync at a reasonable throughput on a long line.
The best indication of what you will get is the Loss and SNR margin that you can find on the modem's web interface. Distance is only a partial indicator, weight of copper is the other. For lines put in over the last 40 years that figure is "cheap". Quality of junctions also matters - I just had Telstra around to deal with one of them - even voice calls failed with water-caused crackle. I'm about a Km closer than you and I get 6.4Mb at a SNR of 7 dB, loop atten 37 dB (the Draytek Vigor120 I'm using gives slightly different info to the Netgear DG834N I was using). The Vigor 120 has an Infineon chip apparently. That data rate is for Internode's "ADSL2+ High Speed" profile. Now the dud junction is gone it has been rock stable. In fact this has prompted me to put in a profile change to Very High Speed. Fingers crossed. While I was typing that, the change happened: 7.2Mb at 4 dB SNR, got a CRC error at lockup 20 min. ago, none since. Is good! For these various profiles the faster the speed, the lower the SNR. The thing to watch is the Rx CRC error rate and the stability of the SNR.