ADSL2 modem stats

[Skylarking]

Hello

I am having some trouble with my connection speeds and i was wondering if anyone that understands modem stats tell me what can be going wrong? I usually get 3Mbps.

Statistics -- xDSL

Mode: ADSL_G.dmt
Traffic Type: ATM
Status: Up
Link Power State: L0

Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (0.1 dB): 94 100
Attenuation (0.1 dB): 635 315
Output Power (0.1 dBm): 166 123
Attainable Rate (Kbps): 1184 424



Some things to note

- i am 4km cable length from the exchange
- nothing else is on the phone line
- this started happening recently and every restart gives that exact same speeds
- tried different modems, cables, outlets and no help
- yes im in australia ><

[Masark]

Your problem is the attenuation, and the resultant noise margin. The attenuation is significantly higher than it should be (you're at 63.5Db attenuation. It should be in the 50s, at most) and the SNR is low (9.4dB, should be 12dB+). The SNR limits the available bandwidth, as shown on the "attainable rate" figure.

Since you've checked the cabling internally, that leaves the problem as being somewhere on the line to the central exchange.

There's nothing you can do about that yourself. Bug the ISP/phone company about it.

[Skylarking]

Thank you for your response!

So the speed problem is fixed, im getting what i usually get now. But you say my stats should be better? I got these stats from another modem in my house and they seem to be a little better. Also my ISP lets me play around with internet profiles, these are the stats when its set to "ADSL2+ standard". There are other profiles as well like adsl2 high reliability, adsl2 high speed, adsl2 low latency and even the equivalent with normal adsl. I was told that for my line being so long its either best set at the standard profiles or high reliability.

What is the difference with adsl standard and adsl2+ standard? Will my speed drop or increase or something?

Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoE 226041 407475 0 3016 83437 01:46:16
LAN 10M/100M 2581167 2820785 0 12407 4333 21:55:51
WLAN 11M/54M/270M 3589091 2042305 0 11269 6196 09:15:08

ADSL Link Downstream Upstream
Connection Speed 3063 kbps 552 kbps
Line Attenuation 59.5 db 38.3 db
Noise Margin 8.8 db 9.3 db

[Masark]

What is the difference with adsl standard and adsl2+ standard? Will my speed drop or increase or something?

ADSL, ADSL2, and ADSL2+ are various standards for DSL. ADSL2 is the sequel to the original ADSL standard and uses more advanced modulation to achieve higher speeds, and ADSL2+ uses a larger range of frequencies in addition to ADSL2's modulation to go higher still. ADSL under optimal conditions is capable of 8Mbps down, whereas ADSL2 improves that to 12Mbps, and ADSL2+ improves that further to 24Mbps.

As a general rule, there's no reason to use the prior standards when ADSL2+ is available.

[Artorius]

In addition to that VDSL can go as high as 55Mbp/s down and VDSL2 100Mbp/s.

[Masark]

In addition to that VDSL can go as high as 55Mbp/s down and VDSL2 100Mbp/s.

Yeah, VDSL and VDSL2 (and the even newer G.fast) go even further on the ADSL2+ throw-more-frequency-range-at-it method and give lots of speed, but only at short ranges (the further you go, the smaller the range of usable frequcies. Past about 3km, VDSL2 performs about the same as ADSL2).

They're generally only used for fibre-to-the-node, cabinet, or building implimentations.

I personally question whether G.fast will ever really be implimented on a serious scale, as at the loop lengths where it would be useful, you really might as well just push the fibre the last couple hundred metres to the premisis and be done with it rather than spend money on the G.fast equipment.