ADSL- Upstream Power: why is this 0 dBm?

ujava · Post by **ujava** » Sun Jan 16, 2005 9:16 am

Hi there, I have posted this question on another forum, but I didn't receive any answer.

I have just bought an ADSL2 router, it's a Netgear DG834GT and it works quite well except from its upload rate.

My adsl line is 12mbit/1mbit, and the router succesfully syncs at 12286 kbit/s downstream but just 661 kbit/s upstream and sometimes even lower.

Here's a short stats from the router:

Code: Select all

Status: Showtime  Channel: FAST, Upstream rate = 657 Kbps, Downstream rate = 12286 Kbps
Link Power State: L0
Mode:                   ADSL2+
Channel:                Fast
Trellis:                ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):       6.8             15.0
Attn(dB):       21.0            9.9
Pwr(dBm):       12.2            0.0
Max(Kbps):      19084           760
Rate (Kbps):    12286           657
                        G.dmt framing

As you can notice the Upstream Power is 0.0 dBm and it really looks strange.

Except this upstream limitation I am not experiencing any disconnection or other sort of problems.

Please notice that the line directly connects from the local exchange to the router. Neither a wall-plate, just crimped the cable coming from the telco.

I have tested on the same line a Zyxel 642R router and it succesfully reach a 1 mbit upstream adsl link but since it doesn't support ADSL2 the downstream is limited to 8mbit.

Does anybody have any clue about my problem? Is 0.0 dBm a valid upstream power value?

Thanks for your appreciated help. Hope I have provided enough information.

ttyy

CBUM · Post by **CBUM** » Sun Jan 16, 2005 11:48 am

Im not sure what DSL specs are but in the cable world we use DBMV to determine signal strength back to the headend. Decible Mili Volts. DSL uses voltages to send information so in the cable world a return rate of 40-55 db is normal for a cable modem to push its signal back to the headend to achive a level of 0 by the time it hits the headend. I gather the modem isnt pushing much at the time you tested it since its running a self test to provide you with the information you got. I could be wrong. A DSL guy may be able to help you more.

ujava · Post by **ujava** » Mon Jan 17, 2005 3:03 pm

CBUM,

thank you for your prompt reply, but I am afraid that my 0 dBm problem isn't linked with the test... I think these are real time values, as a matter of fact googling I have found other people with the same router quoting "correct" upstream power values in the range you have sayd.

I think that it is linked to the fact that the modem can't connect at full upstream rate provided by the adsl line. But I can't figure what is causing this low value...

ttyy

mccoffee · Post by **mccoffee** » Mon Jan 17, 2005 3:51 pm

have a tech come out is the phonewirring old ?? if you know a electrician or a phone tech as a buddy you could try this http://www.broadbandnuts.com/index.php?page=dslwire1

ujava · Post by **ujava** » Mon Jan 17, 2005 4:48 pm

Dear Kent,

thanks for your suggestion. Wiring is really new and just a single cable is coming from the telco NIS to the router. No other appliance is connected on that line. I have also tryed to connect the router directly to the NIS but it made no difference...

I begin to suspect that the router might have some defect...

ttyy