D-Link DSL-502T slow line rate

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garryk

41 posts

Geek

#58551 14-Mar-2010 13:05

Hi all,

My Linksys WAG54Gv3 got blasted in a recent thunderstorm, and after limping along for a while, has now finally gone to the big bit bucket in the sky. I've had to dig out an old D-Link 502T to get me back on line until I figure out what I'll replace it with (suggestions here would be very welcome. I'm looking for anything that can better the WAG54Gv3 performance, which has been pretty rock solid on the DSL front, maybe not so good on the wireless, but I'll probably split the wireless away as a seprate box next time. VoIP FXS/FXO line capability might also get added to the wish list).

The interesting thing I've noticed is that, although the modem has come up in ADSL2+ multimode, I cannot get it to run a faster linerate than 7.5Mbps down/900K up. Some might think that's okay, but my Linksys connected at 11Mbps down/ 900K up on exactly the same connection (no suggestions about filters and all that, please. I'm using a central splitter).

For the record, the modem is reporting
                  Down      Up
SNR                15     12 dB
Atten              28      15 dB
Data rate     7547      901 kbps

(The old Linksys I believe (can't check anymore) had an SNR of 12/12 dB down/up.)

I've had a look around to see whether I have the latest firmware on the 502T, and currently have installed

ADSL Firmware version is 5.00.04.00 - 5.00.03.00 - 5.00.03.00 Annex A - 01.07.2b - 0.52
ADSL Software Version V3.00B02NZ.20060710

which (from the date), looks quite old? But I can't see anything NZ-specific that's newer. Hardware-wise, its not a gen II, its a ver. A5, but I believe these are supposed to be capable of ADSL2+ speeds (unless anyone knows better?).

(Note: The 502T status page reports both ADSL Firmware and ADSL Software versions? The Firmware version didn't change when I upgraded, only the Software version. Is it separately upgradeable?)

So, my question is, does anyone have an explanation as to why I can't get the same higher line sync rate I was getting on the linksys? I'm on a FS/FS plan with Orcon, and they couldn't explain it. Is there a later software or firmware version I can load? Or is it something else? TIA

Ragnor

8085 posts

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#307118 14-Mar-2010 17:14

Different hardware, the Linksys uses a Texas instruments chipset for the modem and the D Link uses a GlobalSpan (I think, the Gen I does anyway). The gen I version of the 502T is very old and does not support ADSL2+ sync speeds.

I'd recommend you switch to a proven broadcom chipset modem/router/wireless ap like the Dynalink RTA1025W (~$120).

http://www.gearbot.co.nz/store_products/search/dynalink%201025/

MightyApe

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webwat

2036 posts

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#307817 16-Mar-2010 14:05

Some of the DLinks had compatibility issues with ADSL2+, but its fallen back to ADSL so thats good. You could set the modem to ADSL2 or ADSL2+ and see if it synchronises, but you have noise margin to spare so I dont think your splitter was damaged by the lightning strike at all.

Maybe put your flash new router onto a UPS to protect against future surge/spikes though, you dont want the next power fluctuation/cut to take out your VoIP along with internet. And keep in mind that you will have double NAT issues if you go for a separate wifi router next time.

Time to find a new industry!

farcus

1455 posts

Uber Geek

#307835 16-Mar-2010 14:51

there is a know problem with the dlink 502 and 504 routers that limit the adsl 2 speed to 7.5MB.
Telecom did develop a firmware update that fixed the problem but then switched to Thomsom for their modems and refused to release the firmware update.

Apparently firmware updates from the DLINK website do not fix the problem for NZ

garryk

41 posts

Geek

#308954 18-Mar-2010 22:47

Thanks for the responses.
Of course, my last router was on a UPS, along with my Disk Station, but ironically the UPS dying (battery finally gave up the ghost) could have been what helped to take it down!? Not sure which came first, the lightning damage or the UPS battery dying. Probably the UPS was already flaky and the lightning/power surge finally toasted it, causing low volts on the UPS output, stressing the load hanging off it.

I'm not much of a fan for Dynalink, I'm afraid. Am looking at an Asus DSL-N11 or N13. I believe (but can anyone confirm if?) these have a Broadcom chipset. I keep hearing Billion 7800N's are quite good, but perhaps a bit pricier than I want/need.

Other candidates for DSL and/or Wireless devices are:-

ASUS RT-N16
UBNT Rocket M2
Draytek Vigor 120
TPLink TD8840

Bit of a mixed bag I guess, but am trying to keep an open mind at the moment.
Any other suggestions are welcome, but I guess I'm now getting a bit OT, so I should bring things back to the DSL-502T.

The implication from the responses is that a new firmware could have made the line rate quicker, even with this generation of hardware?That would match with what I've read on overseas forums. So, given the TNZ developed code is not available, how differently would the DSL-502T behave in the TNZ network if flashed with an Australian variant of the code?

Ragnor

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#308977 19-Mar-2010 00:35

I think you might aswell try the AU firmware, just remember to change the settings to the NZ ones (PPPoA, VPI 0, VCI 100 etc) not much to lose.. if it doesn't work you're going to get a new modem that fully supports ADSL2+ anyway.

Few questions:

1: How much do you want to spend ideally?
2: Do you want an all in one unit or is a separate modem and router solution fine?
3: Do you want wireless N?
4: Do you want Gigabit lan?