Dual WAN

[Tomken]

What are the router settings in order to use Dual WAN and what are the advantages of this - if any ?

[billion_fan]

Dual WAN on the 7800N does not run concurrently, so you can not use both WAN's at the same time.

The Dual WAN feature is for auto fail back, meaning if the ADSL fails (drops sync or drops PPP) you can set the router to fall over to the EWAN connection, to make sure you have a active internet connection.

This will work visa versa, EWAN fails, then the internet connection can fall over to the ADSL connection.

You can select this by changing the WAN interface to Dual WAN, and set the primary connection as you wish and the secondary connection (which it will fall over to)

I hope this explains the Dual WAN feature.

[Tomken]

Thanks billion_fan, I had seen the WAN setting for this but wasn't sure of the effect it may have had on ADSL, as that is my usual connection.

Does the cable always have to be connected in this mode or does the mode need changing back to ADSL (selecting ADSL/EWAN and "Keep Backup Interface Connected" enabled) when wanting to use wirelessly - i.e. using the laptop in another room from the router ?

Going off topic, had a disconnect a few days ago and it resync'd at over 2 meg less - have since managed to get it back up but the best it will do is about a 0.8 meg less than what it was before. Attenuation is 50dB.

The Downstream and Upstream SNRMs are at 6dB which is the profile I'm on and was wondering if this is down to a deterioration of the line or a router problem

[billion_fan]

Hi Tomken

Using the Dual WAN feature you will have to remain connected to the EWAN port on the 7800N as you can not tell when your ADSL will drop so here is the example.

7800N connected with a ADSL conenction and EWAN connected to a Virgin Cable modem, if the ADSL connection drops then router will use the Virgin Modems connection (fail over), to provide the house hold with internet access.

Once the ADSL is back up the router will automatically change back over to the ADSL connection, and so should provide a household with a non stop internet connection (well not non-stop a small delay when changing over the WAN services)

You should not have to change any settings on your laptop as they will be connected to the 7800n ESSID, the 7800N will fallback/failover to and from the ADSL connection when and if there is a ADSL drop out.

[billion_fan]

regarding your ADSL sync rate issue, you can always adjust the SNR via the http://192.168.1.254/snr.html to boost your ADSL downstream speeds.

As you have stated your SNR reading is 6db maybe you can try and set the SNR to 75 and check the speeds again.

If the router is syncing up and holding sync this is not a router issue, you can try and connect the router to a diffrerent line and check if the router syncs at higher speeds.

It could a tempory issue line issue, try and resync again after a couple of days.

Also have your checked for CRC or FEC errors?? I am writing a autotelnet script that will output all telnet findings to a txt file, this will show the CRC and FEC error, and loads of other stuff, I might start a thread with this autotelnet tool for people to try

[Tomken]

Right - got that.

Just had a look at the log and it seems to be quite chatty - is this normal.

I'd add the screenshot - but it won't let me copy & paste or enter the file name for the attachment

Setting the SNRM to 75 only increases the bandwidth by about 0.4dB but the FECs are very high on that now whereas when I first set the 7800N up it was running OK on that.

I've done a reset each morning since but with no improvement and it could be a temporary thing as a couple of weeks ago, the SNRM was sitting at 8.4db and I managed to get it back up to 6383dB (and held for about 12 days) which was somewhere near what I was getting but did have some line problems prior to that and was sync'd at about 5.6ish.

Current stats after 45mins are

Down / Up
FEC 951856 / 0
CRC 4 / 35
ES 3 /33
SES 0 / 0
UAS 34 / 34

[billion_fan]

Hi Tomken

Here is a link to expain what Forward Error correction (FEC errors) are.

http://en.wikipedia.org/wiki/Forward_error_correction

Maybe this can help to explain what is happening with your line

[Tomken]

Well, I know that on a tweaked 4.5dB profile, the FECs are in the millions after just a short time and the resulting lag due to retransmissions.

Any thoughts on why I can't attach the screenshot either from a snip or a paint image.

[billion_fan]

Normally when replying at the bottom of the message you are typing, there is two options 'Options' and 'Upload Attachment' when you click on 'Upload Attachment' you should be able to select a file name eg capture.jpg and click on 'Submit'

[Tomken]

That's what I thought, but it wouldn't let me browse or add the file.

Seemed a bit erratic this time but here are the log entries I tried to submit earlier.

EWAN Log.png