Current Rate and Maximum Rate during DLM explanation

[Flying-Chips]

Hi all, I'd like to gain an understanding about the Vox3.0 router as coming from Sky they only ever showed one figure for sync speed in their router. I was quoted I could receive upto 62Mbps download. I understand I'm currently going through DLM as I've just been activated, so know my speed will fluctuate.

During DLM what figure will change, is it the Current Rate or the Maximum Rate? With Sky I was reliably receiving 55Mbps download. I'm hoping that the currently showing 45Mbps isn't the max I'll receive otherwise I'll be moving.

Line Quality

  Downstream Upstream

Current Rate	38429 kbps	13063 kbps
Maximum Rate	45622 kbps	13063 kbps
Signal-to-Noise Ratio	6.2 dB	5.9 dB
Attenuation	DS1 14.7 dB, DS2 35.7 dB, DS3 55.3 dB	US0 4.7 dB, US1 27.1 dB, US2 42.7 dB

[Flying-Chips]

Hi all, my question has been answered. My router just rebooted itself and the Maximum Rate has changed. Not sure why the Current Rate isn't close to the Maximum Rate though. This can be used as reference in the future. Thanks 👍🏼

[Anonymous]

VDSL speeds and how they are achieved are much more complicated than someone somewhere flicking a switch which is a common misconception.  One thing to consider is that both your upload and download data, travel along the same two wires.  As a result, increasing your download speed can decrease your upload speed.

So, on my own connection, with a third-party modem, I've set it to get 49Mbps download and just 10Mbps upload, but by changing the "Signal-to-Noise Ratio" on the modem, I can adjust that to around 43Mbps download with 16Mbps upload.  Vodafone's modem+routers tend to take a middle of the line approach so with the VOX2.5 device I'd get around 46/13, but many ISPs favour download speeds over upload.

If you want tons more info you could try http://www.kitz.co.uk

[flilot · Accepted solution]

Max rate will vary a lot, different times of day, different times of year, how many other users are connected to the same cabinet as you causing crosstalk, etc etc. It's generally a figure that, all things being "perfect" (which they never are) your line would run at maximally, taking into account your line length, attenuation, and other factors, under current conditions. 

However, how your line is configured by DLM also has a bearing on the Max figure: if your line is currently interleaved, the max figure can be overstated.  New connections are generally interleaved to start with (even coming from a previous ISP to Vodafone you'll be classed as a "new" connection) and have a target Downstream Signal-to-Noise Ratio of 6dB.   If you are connected to a Huawei cabinet, DLM is usually pretty swift in action (within a week or two) if your line is stable, you'll be switched to fast path (instead of interleaved), and should find your Downstream Signal-to-Noise Ratio will lower in steps, which will increase your current rate as well as max rate (which is reported more correctly on fast path). You may also have G.INP applied to your line which will help speeds and stability even further.

However if you are connected to an ECI cabinet, things are more blurry, G.INP is not supported by default on these cabinets, so speeds are generally lower than Huawei connected lines, and DLM to remove interleaving and put the line onto fast path can take a lot longer (if at all).

Probably a lot to take in, but, just keep an eye on the line stats over the next week or two and you should see changes - don't be alarmed if your connection drops in the early hours of the morning at some time, as thats generally when DLM acts, and resync will occur after changes are applied.

[Flying-Chips]

Fab, just realised I didn’t actually ask a question in my haste yesterday afternoon, haha. You read between the lines though. Appreciate the detailed response. Some I already knew but didn’t know the ins and outs regarding different cabinets and how they manage dlm. Anyway to tell the difference between the cabinet types?

Additionally, any idea was Current Rate is slower than Max Rate. Is it because Max rate is exchange to cabinet (fibre) and current rate is cabinet to property (copper wire)? As mentioned before, Sky only ever reported one figure on the router which I believe was the Current Rate.

[clint_flick]

Hi

As you say you will need to wait.

Your SNR is about 6 so......................

https://www.broadbandchecker.btwholesale.com/#/ADSL

Downlink target SNR margin (dB) Downlink connection speed (kbps)

18 (worst case)	3008
15	3616
12	4096
9 (TalkTalk's initial default)	4768
6 (BT's initial default)	5568
3	6240
1	6624

 Table: Effect of target SNR margin on downlink connection speed

[Flying-Chips]

Saw the table you’ve shared whilst browsing yesterday. However, that link you’ve supplied it incredibly useful, especially the cabinet number and the details they share about what’s available etc. 

[clint_flick]

Prego.

I used to get updates from my county council on broadband roll-outs that the 50p levy was funding.

https://www.cswbroadband.org.uk/

AND I got that specific one from this forum.

So my actual brain was NEVER ever engaged to provide that post.