Broadband Faults Guide - Banding Guide

[#1]

21CN (Up to 16Mb)

WBC 160k - 288k	160kbps to 288kbps
WBC 288k - 576k	288kbps to 576kbps
WBC 576k - 1M	576kbps to 1152kbps
WBC 1M - 2M	1152kbps to 2272kbps
WBC 1M - 3M	1472kbps to 3072kbps
WBC 2M - 4M	2272kbps to 4544kbps
WBC 3M - 6M	3328kbps to 6656kbps
WBC 4M - 9M	4864kbps to 9728kbps
WBC 7M - 14M	7168kbps to 14336kbps
WBC 160k - 24M	Unbanded (up to 24576kbps)

 Above are the levels of banding that can be applied to your line by DLM (Dynamic Line Management). Banding is applied when your connection drops on a regular basis. The banding slows your connection by restricting your connection rate. For example, if your connection drops 10 times within 24 hours, you may notice that your connection is banded to WBC 4M-9M this means your connection will only be allowed to synchronise at a maximum of 9728Kbps. Your speeds are lowered to try and help your line stabilise.
Normally, your line should be WBC 160K-24M which essentially means, your connection can synchronise anywhere between 160Kbps up to 24576Kbps – this is a profile with no banding on it. In a lot of cases if you have a fault where your connection has dropped out, your profile will be restricted to WBC 160K-288K which means you’ll only see speeds of around 250Kbps.
 
If the INP value is either 4 or 8, this means the line is chronically banded – meaning that DLM will not be able to remove the banding on the line – it will need an SNR Reset (by an engineer or our Faults Team).
 

20CN (Up to 6Mb)

There is no line banding on 20CN circuits. The connection speeds are controlled by either increasing the SNR or by restricting the IP Profile. Please see the below table:

Sync speed (incr 32kb stages)		IP profile
From	To
160 kbps	256 kbps	135
288 kbps	384 kbps	250
416 kbps	544 kbps	350
576 kbps	832 kbps	500
864 kbps	1120 kbps	750
1152 kbps	1408 kbps	1000
1440 kbps	1696 kbps	1250
1728 kbps	1984 kbps	1500
2016 kbps	2240 kbps	1750
2272 kbps	2816 kbps	2000
2848 kbps	3392 kbps	2500
3424 kbps	3968 kbps	3000
4000 kbps	4512 kbps	3500
4544 kbps	5088 kbps	4000
5120 kbps	5664 kbps	4500
5696 kbps	6208 kbps	5000
6240 kbps	6784 kbps	5500
6816 kbps	7360 kbps	6000
7392 kbps	7936 kbps	6500
7968 kbps	8096 kbps	7000
8128 kbps	8128 kbps	7150

The above table shows the IP Profile’s that are available based on your synchronisation rate. For example, if you have a synchronisation rate of 4500, you will be assigned an IP Profile of 3500 – this equates to around 3.4Mbps.
 

FTTC (Up to 76Mb)

More, in depth information on how these figures are used in our own internal testing can be found on the Faults Testing guide.

[#2]

What is "by restricting the IP Profile" in the 20CN section supposed to mean? You made it sound like restricting the IP Profile is an alternative strategy for the DLM to take instead of increasing the target SNRM, which sounds a lot like banding, and isn't what happens.

[#3]

Thanks for commenting.
I'm sorry if that's how I've made it sound. If the SNR increases, the sync rate will fall, naturally the IP Profile will drop to match this. The IP Profile can be adjusted if required, but this isn't something that we would do, actively.

[#4]

Shouldn't the speed range on the
WBC 2M - 4M 2272kbps to 4533kbps line be
WBC 2M - 4M 2272kbps to 4544kbps ?

[#5]

@spraxyt - thanks for flagging, that's been amended now.

[#6]

I have had an ongoing problem with my broadband for 3 months. Had 3 engineers visit the house and 3 subsequent training period following their visit. After each time the line is great during the training.. no loss in signal and good download speeds etc etc then as soon as the training completes I go back to a low synch speed and associated low downloads. Everytime somone has run these test on the raised question it shows I have WBC 1M-2M with an INP of 4 or 4.5. This is the case even during any training period. Also one technician said plusnet had not recieved any update for my profle from the exchange for weeks/months. So you say that an INP of 4 means the line is chronic banded and the dlm cant change it. How can I get this changed? No one I have spoken to seem to know what I am talking about when I have asked. Havve searched about INP and banded profiles and cant find anything about them being related anywhere other than this post.
Thanks
(Moderator's Note: Duplicate comment removed. David (spraxyt))

[#7]

Hi awigham,
Apologies for the very delayed response. If you're seeing unusual issues such as this, then we would normally expect to see your connection dropping out. If this is happening and your connection is staying stable, we could look at getting you put onto a 'NonBanded Profile' which would stop the banding from occurring.
If you've a Forum Thread of Ticket Reference you can refer me too, I'd happily take a look for you.