On 28/05/13 6:22 PM, Allan Duncan wrote:
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. Well, the line is 4.6km according to Internode, and various modems have got speeds ranging from 1 to 4.2 Mbps. The Fritzbox was managing 1Mbps with some tweaking. However, I have managed to make a considerable improvement by puting an old D-Link DSL-502T into bridge mode and setting it for ADSL 1 (G.dmt). This has increased my speed to 3.6 Mbps, which is in the range I would regard as acceptable. Interestingly, this modem wouldn't sync at all in ADSL 2+ mode. Other modems tried include a Netcomm modem (loan unit) at 2.8-3.0 Mbps, and a Bigpond modem at 4.2 Mbps.
Unfortunately, I am unable to check the SNR margin on the D-Link easily, because I can't access its web interface due to routing issues, unless I take the router out of circuit, and connect a PC directly to the modem, or add a switch, so I can connect a PC at any time (the web interface and DHCP server do remain active for the LAN port in bridge mode). From memory, I think it was around 6 or 7 dB at 3.6Mbps sync speed.
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.
I'm on a Telstra exchange here, so can't access line profiles. No choice. Optus is in town, but effectively can't get Optus powered services due to RIMs and/or pair gain on the Optus network (the coverage checker says you can go through Optus, but the change request will fail - I've tried at two different addresses). Internode will probably never install a DSLAM out here. As for NBN, it's still more than 3 years away (i.e. not on any of the rollout schedules yet :( ). -- 73 de Tony VK3JED http://vkradio.com