Sync is short for synchronised speed, and is the speed the modems at each end have agreed to use. They are synchronised. It is the speed that bits are passing to and fro at all the time, whether or not any data is being transferred. The HG612 calls it the "Path Rate".

The "Max" figure is not the sync, it is what is theoretically attainable if product structures such as 80/20 and 40/10 were not in place.

Edited by RobertoS (Wed 21-May-14 17:54:38)

Remember though that the allocation of tones/carriers is NOT dynamic, it is fixed for each ADSL or VDSL variant so a user will not see bandwith taken from Downstream and given to Upstream.

Yes, I forgot to say that choice of bandplan is not a dynamic thing, per user. It has to be selected once for everyone who is connected to a VDSL2 cabinet or (in the case of SLU) any of the cabinets which serve a given cable bundle.

Crosstalk problems are too high if bandplans get mixed up.

As RobertoS said, you are actually sync'd at 64505/19999.

Your SNR level indicates 6.1dB, so you are pretty much synchronised at the optimal speed for your line; that suggests you have not had a DLM cap applied to the line.

You just managed to include the details (R=0, D=1) that show you do not have FEC or interleaving activated downstream, suggesting that DLM has not intervened that way either. The modems have chosen to activate FEC upstream, but that is common on lines where there is plenty of spare capacity; we can't tell what DLM has ordered precisely (you need to scroll down further to show INP and delay figures for that), but it is likely to be 0 for both. FEC will be using some of that spare bandwidth to offer protection, but it hasn't included interleaving (which would add latency).

Scrolling down, you will see lots more statistics for your line, showing how many errors you are getting.

So...

It is unusual to see a downstream attainable of 65Mbps alongside an upstream of 30Mbps (mine are currently 80 down and 24 up), suggesting that you are seeing some interference. The modems seem to be measuring that interference as a high level of regular noise (so are keeping your speed low), rather than bursts of interference (which would give you higher speed but lots of errors). Or there might be some kind of fault on your line.

We can't see exactly what you *ought* to get, as these stats don't show us the attenuation values properly. The "--pbParams" output will help there, but I don't know if you can get that from DSLstats.

Can I suggest that you try installing the other set of monitoring software, the modem stats? These will let you generate graphs that show line conditions per frequency, which might show a problem.

http://forum.kitz.co.uk/index.php?board=46.0

In reply to a post by WWWombat:

It is unusual to see a downstream attainable of 65Mbps alongside an upstream of 30Mbps (mine are currently 80 down and 24 up), suggesting that you are seeing some interference. The modems seem to be measuring that interference as a high level of regular noise (so are keeping your speed low), rather than bursts of interference (which would give you higher speed but lots of errors). Or there might be some kind of fault on your line.

65/30 Attainable is certainly a little exceptional but not impossible. Due to distance I am on 58 down and 25 up (attainable) so not far off.

In reply to a post by WWWombat:

We can't see exactly what you *ought* to get, as these stats don't show us the attenuation values properly. The "--pbParams" output will help there, but I don't know if you can get that from DSLstats.

On my copy of DSLstats (which is a test one, v4.53.2), it's the 3rd sub-tab under the Telnet Data tab:

xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 10634 Kbps, Downstream rate = 53992 Kbps
Path: 0, Upstream rate = 10671 Kbps, Downstream rate = 46159 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959) (2792,4083)
Medley Phase (Final) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 10634 kbps 53992 kbps
Actual Aggregate Tx Power: 6.1 dBm 11.8 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 4.5 36.3 51.6 N/A 18.1 46.8 73.3
Signal Attenuation(dB): 4.5 36.2 51.4 N/A 18.1 46.8 N/A
SNR Margin(dB): 6.3 6.0 6.2 N/A 6.2 6.2 N/A
TX Power(dBm): -3.6 -4.7 5.0 N/A 10.0 7.4 N/A