lost around 30% of sync speed in 2 years on fttc.

My contract is nearly up with zen and I thought I would start looking around for other company's to see what deals are available. I went to the zen homepage and input my phone number to see what sync speed I would roughly expect nowadays and it was a big difference in what I am actually syncing at. Currently I'm syncing at 47.9 Mbps when the checker says I should be more in the region of 63.3Mbps. Now I understand that this is a ballpark figure and that over time crosstalk would play a part but not quite to that extent.

My ping time has also nearly doubled in the 2 years which to me is far more important. I checked my ping graph and noticed I have been getting weird lag spikes for around the last 6 weeks http://www.thinkbroadband.com/ping/share/d2478e3d792...
Would this also be cause by cross talk?

I have router stats available and can see lots of errors but apart from that I really dont know what they mean.

Looking for some advice about what the possible issues are.

Looks more line a regular speed test or other use of the connection

Only one laptop and its off most the time I do stream netflix and youtube but the large regular spikes are an unknown.

router stats

Mode VDSL2
Traffic Type PTM
Status Up
Link Power State L0
Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 5.9 6.4
Attenuation (dB) 0.0 0.0
Output Power (dBm) 13.6 6.6
Attainable Rate (Kbps) 53592 21639
Rate (Kbps) 47904 20000
B (# of bytes in Mux Data Frame) 51 236
M (# of Mux Data Frames in an RS codeword) 1 1
T (# of Mux Data Frames in an OH sub-frame) 64 5
R (# of redundancy bytes in the RS codeword) 12 16
S (# of data symbols over which the RS code word spans) 0.0345 0.3771
L (# of bits transmitted in each data symbol) 14824 5410
D (interleaver depth) 937 1
I (interleaver block size in bytes) 64 255
N (RS codeword size) 64 255
Delay (msec) 8 0
INP (DMT symbol) 3.00 0.00
OH Frames 197477511 71041368
OH Frame Errors 73 285
RS Words 3169066819 2659961
RS Correctable Errors 1838941888 1201
RS Uncorrectable Errors 1758 0

Nothing jumps at me from modem stats

Forgive me if I'm barking up the wrong tree but isn't it unusual or maybe a fault that the upstream is synced a lot better than the downstream and also the latency depth on the upstream is a lot lower than that of the downstream?

Morning,

Have you tried contacting support yet at all? They can see the history of the line speed and see when it started to drop and whether or not it is gradual or sudden. Worth a call in my opinion.

Rate (Kbps) 47904 20000

Not that unusual, the upstream and downstream frequencies are interleaved blocks unlike with ADSL2+. So you do get oddities where downstream is degrading already but upstream still good. Also the different power masks for cabinets can cause variations too.

There may be some local spot noise impacting a few downstream bins, but without a full bin plot difficult to say a lot.