I took drop-outs to mean those where your up and down sync speeds and SNR all simultaneously drop to zero rather than those where just the SNR drops.

In reply to a post by MHC:

I took drop-outs to mean those where your up and down sync speeds and SNR all simultaneously drop to zero rather than those where just the SNR drops.

Sometimes the dropouts are only caught on the SNR trace, but they're all from the same effect. See this topic http://forums.thinkbroadband.com/multiuser/t/4302327...

In reply to a post by Mygri:

I've just posted a link to a line stats graph in response to ian72's post. I don't know whether you'd consider the SNR stable or not.
.,snip..
the ISP person that I spoke to was knowledgeable, informed and helpful; even so, she was quite clear that there was evidence of 'interference', although perhaps I should have pressed her a bit harder about its nature.

The graph shows a slight drift in noise margin with minor spikes. I'd consider it to be fairly stable. It is just possible that there are multiple short outages that were not caught by your sampling but checking the connection uptime in your router stats should reveal that. My betting is that it hasn't dropped at all and the ISP rep is just giving you some BS. All that they would be able to see is whether or not you had had disconnects and my betting is they don't actually monitor anything at all. It is possible to sound quite convincing while talking complete drivel - if that were not the case the likes of PC World wouldn't be able to charge £30 or so for a short HDMI cable.

If this were my connection and the connection uptime confirmed there are no WAN dropouts I'd ask them to reset the noise margin to default. If they wouldn't then I'd change ISP. What you do is entirely up to you of course.

I took the OP's comment in the same post as the image at face value:

Ignore the dropouts - these are due to interaction between the router and the NIC

If the router is actually dropping out and not just the local LAN connection then I agree there are issues. But, if the above is correct then it isn't a WAN issue to be concerned with.

If your router is not disconnecting and it is dropouts on the LAN as per your post then your connection looks reasonably stable. Ask the ISP to drop the SNR to 6dB and if they talk about noise or dropouts then ask for their evidence as your graph doesn't suggest there are issues (at least in that 24 hour period).

Hmmm... food for thought.

The router sampling rate is set to 5 sec, the smallest interval it will go to. I've not seen any WAN dropouts, but as you say, some shorter breaks could be occurring undetected. Over 24 hrs though, some would inevitably be seen if they were occurring at any credible intervals.

I'll get in touch with the ISP again and quiz them more closely about what they claim to be seeing. I take your point about BSing, but I certainly didn't get that impression, and as an engineer, I can usually tell when someone's trying to pull the wool on technical issues. That said, your point about gold-plated HDMI (and other AV) cables is spot on!

Unless they can provide some evidence that there is a problem, I will ask for a reset; your and ian72's comments that the SNR looks fairly stable suggest to me that this the next thing to try.

Hi,

I've just posted a reply to kwikbreaks, which directly relates to your input as well. This all seems to be pointing in the direction of asking for a target SNR reset.

My looking at it was that a dropout would stop ALL data being transferred across the LAN, Up Sync, Down Sync and Down SNR whereas there are significant periods where the Sync data is being received correctly but SNR is at zero. Look closely at some of the complete SYNC drops especially those towards the right and you should be able to make out an SNR drop just before.

I see what you mean. It is difficult to tell with a single graph with all the values - would be easier with separate graphs or the data set itself to see exactly what is happening. Key to me is knowing uptime of the router which is the information we don't have at all.

It won't lose and re-establish sync inside 5 seconds. In any event check what the router says the connection uptime is.

Worth looking and any stats you can find on errors too - FEC errors can in the main be ignored as they were corrected but CRC errors are bad news - in effect a dropped packet which will have to be re-transmitted. Some routers (Thomson/Speedtouch) report unbelievable numbers for FEC errors but sfaik nobody has questioned Netgear reporting of them. Many will have been picked up during the initial speed negotiation so look for changes over time - ideally from after a reboot but it's not worth doing that just to check.