Different DSL noise margin from different routers

Kencollins

Hi all,

I am a new DSL customer to Vodafone, and it was connected today. I am on an unbundled exchange, and the 24mb package.

I am 1.8km from the exchange and getting 10.5mb download speed.

I set up the broadband with an Eircom router I had lying about. The attenuation downstream was 26, DSL signal noise margin was 12, connected at 12225.

When I changed to Vodafones modem (using all the same cables ect) the signal noise margin went down to 6.2. It still connects, runs at the same speed, but the margin is hugely different!

The Vodafone router is a huawei HG556A.

Anybody have any ideas?

Israeli Superiority

I think you should be more worried about your speed because at that distance from the exchange, you should be getting 18 - 19mb.

I get 10.5mb and I'm 2.0km from the exchange, I should get more but my noise margin is around 7db, any lower and my line will suffer from drop-outs.

dub45

What's your internal wiring like? Any extensions?

Kencollins

Hi, thanks for the replies!

I am not too bothered by the speed. It is nearly 11mb, and the rep on the phone said that the most I could expect was 12.5 to 13. I'm coming from fixed wireless 3mb so it's a big improvement!

I have no extensions connected. The eircom line comes up out of the ground behind the skirting board. I have it joined to 1m of cat5e, running through a wall into the next room. It then terminates into the eircom box. I wired the box myself with the plastic idc tool. Then there is a filter and 3ft of standard phone cable to the modem.

The DSL has been solid for 24 hours with the modem reporting no disconnects and the speed is constant.

Which reading should I trust? Xyzel router says s/n margin 12, Vodafone one says 6.2.

I really don't like the Vodafone one anyway. It is trying to do too much (HSDPA, ADSL, WIFI, Telephone) and the switching clicks coming from the inside when you turn it on sound weird!

Kencollins

unless....could the vodafone router be reporting it's "target" signal/noise margin as set by the dslam?

Either that or it's faulty. I dont know which one to believe, or whether I should get on to vodafone and see if they can up the speed a bit.

Ken

Alun

It's quite common really. Some DSL chipsets just seem to work better with certain manufacturers' DSLAMs than others for some reason, plus the firmware can also play a part. So you could try 20 different modems and get 20 different results.

ED E

The 556As are cheap enough gear, and locked down for a lot of users. That said the 660HN and HW from Zyxel are nothing special either. If you had the D1000(HNU) I'd expect to see slightly better performance, but with a HN/HW(which is what you'd have) it should be flat enough with the 556 so I'd say that 556 is malfunctioning.


I'd suggest setting up the Zyxel with Voda PPPoE details and using that.

Kencollins

Thanks for the replies!

I have the Zyxel in bridge mode with the PPPoE details in my own router running openwrt. It all seems to be working well that way, with the S/N margin staying above 12.

I wonder would Vodafone be able to increase the profile by a few mb since there is some headroom on the noise?

bluemachaveli

Kencollins wrote: »

Hi all,

I am a new DSL customer to Vodafone, and it was connected today. I am on an unbundled exchange, and the 24mb package.

I am 1.8km from the exchange and getting 10.5mb download speed.

I set up the broadband with an Eircom router I had lying about. The attenuation downstream was 26, DSL signal noise margin was 12, connected at 12225.

When I changed to Vodafones modem (using all the same cables ect) the signal noise margin went down to 6.2. It still connects, runs at the same speed, but the margin is hugely different!

The Vodafone router is a huawei HG556A.

Anybody have any ideas?

There is a difference in quality of the modems. I had Eircom push my profile upto 15Mb (Line is rated for 12). Works perfect with my Netgear modem, Constant issues with the connection dropping on the 556a and Eircom Zyxel.

ED E

Kencollins wrote: »

I wonder would Vodafone be able to increase the profile by a few mb since there is some headroom on the noise?

Next profile is 15Mb, not sure you'd make that.

Kencollins

Thanks for all the replies.

In the end I didn't bother getting the profile changed, i'm happy with 11 and perfectly stable.

The HG556A really is a heap of crap with the vodafone firmware. I wonder where they went so badly wrong. I flashed it with openWRT, assigned lan port 4 as the wan port, and it's a fantastic router now! Running a media server from a usb stick in the 3g slot and implementing proper QOS makes it really worth the 30 euro that it cost!

It is a pity that the openWRT firmware doesn't support ADSL directly, you have to use it with a bridged adsl modem to get the pppoe working.