I wonder what the big hole starting around 1.6 MHz is about on the SNR graph.

Each tone should be loaded to an SNR margin equal to the target, give or take a bit for the fact that bits/tone is an integer value. Some low frequencies may be higher in SNR margin if they hit the bits/tone ceiling.

Best guess there's a slight compatibility issue between the chipsets in the DSLAM and in your router, causing a sub-optimal negotiation.

These happen, hence why some CPE sync somewhat higher than others on the exact same line.

http://forum.kitz.co.uk/index.php?topic=13125.0
http://forum.kitz.co.uk/index.php?topic=13186.0

Perhaps he was a WWII 'das boot' submariner operating the sonar, and is obsessed with *ping* *ping*

Nick

In reply to a post by Ignitionnet:

Best guess there's a slight compatibility issue between the chipsets in the DSLAM and in your router, causing a sub-optimal negotiation.

I don't think the above is cause. What in it would consist? Is my router only at some connections incompatible with DSLAM and also badly measures SNR margin? Furtermore, DSLAM was changed, the problem is still actual.

Edited by konrado5 (Mon 04-Nov-13 19:30:14)

In reply to a post by konrado5:

In reply to a post by Ignitionnet:

Best guess there's a slight compatibility issue between the chipsets in the DSLAM and in your router, causing a sub-optimal negotiation.

I don't think the above is cause. What in it would consist? Is my router only at some connections incompatible with DSLAM and also badly measures SNR margin? Furtermore, DSLAM was changed, the problem is still actual.

You said the problem started when you moved to the new DSLAM.

My ISP recently changed DSLAM. On previous DSLAM I did many recyncs at 5 minutes and I had either 1277 kbps with SNR margin 7.0 dB and power output 11.3-11.9 dBm or 1260-1277 kbps with SNR margin about 6 dB and power output 12.4 dBm. At new DSLAM I have immediately after recyn SNR margin about 4.6 dB, however after 20 minutes SNR margin is 6.8 dB.

It would seem fair to say that the DSLAM has a different chipset, or that the new DSLAM has a defective port / line card.

Thanks. *Leaves thread*

In reply to a post by Ignitionnet:

You said the problem started when you moved to the new DSLAM.

I apologize but my English is poor. I had something else in mind. At new DSLAM I have immediately after recync SNR margin about 4.6 dB, however after 20 minutes SNR margin is 6.8 dB. I have only one errored second for upload at three days and 0 bitswaps except first 20 minutes of new synchronization. However both on new and old DSLAM I have often lower SNR margin at lower synchronization rate, higher power output and the same used tones than at higher synchronization rate, higher power output and the same used tones.

Actually why's this in the fibre broadband section too?

In reply to a post by konrado5:

At new DSLAM I have immediately after recync SNR margin about 4.6 dB, however after 20 minutes SNR margin is 6.8 dB. I have only one errored second for upload at three days and 0 bitswaps except first 20 minutes of new synchronization.

so there were bitswaps or not, in this first 20 minutes ?