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Banded profile FTTC

Muttley62
Grafter
Posts: 130
Registered: 22-03-2013

Banded profile FTTC

Assuming that my line is good with no problems, what reason could there be for being on a banded profile on fibre?
4 REPLIES
Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: Banded profile FTTC

What makes you think you are on a banded profile?
Muttley62
Grafter
Posts: 130
Registered: 22-03-2013

Re: Banded profile FTTC

We'll, since having fibre installed my download speed has consistently been around 40 meg rather than the estimate of 57 ish.  This has been investigated and two openreach engineers have been to my home and I have spoken at length to Plusnet customer support.  The result is that the line is OK and that the speed is probably consistent with line length.  However, I appear to be on a banded profile as per here:-
Network Incidence Check: Pass
Test Outcome Pass
Test Outcome Code GTC_FTTC_SERVICE_0000
Description GEA service test completed and no fault found .
Main Fault Location OK
Sync Status In Sync
Downstream Speed 43.9 Mbps
Upstream Speed 7.1 Mbps
Appointment Required N
Fault Target Fix Time null
Fault Report Advised N
Profile Name 27M-54M Downstream, Interleaving Off - 3.6M-7.2M Upstream, Interleaving Off
Time Stamp NA
Parameters MIN MAX AVG
Down Stream Line Rate 43.7 Mbps 43.7 Mbps 43.7 Mbps
Up Stream Line Rate 7.0 Mbps 7.0 Mbps 7.0 Mbps
Up Time 25200 Sec 86393 Sec 75401 Sec
Retrains 0 0 0
Current and Last 15 Minute Bin Performance
Last Traffic Count(Upto 15 mins) Current Traffic Count(Upto 15 mins)
Start Time Stamp 2013-05-21T12:12:59Z 2013-05-21T12:27:59Z
Ingress Code Violation 16 2
Egress Code Violation 10 0
Errored Seconds 5 0
Severely Errored Seconds 0 0
Unavailable Seconds 0
Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: Banded profile FTTC

Ah, right, that looks fine and looks quite standard. I'll just see if I can dig up the reference for you.
Right here you go, my bold -
Quote from: SIN498v4p3
2.2.1  Dynamic Line Management
Dynamic Line Management (DLM) is employed  in GEA-FTTC.  DLM constantly
manages lines to maintain a target link quality (speed and stability).  It does this for as
long as the product exists.
At provision, the line is put on  “wide open”  VDSL2 line  profiles allowing  the
upstream and downstream line speeds  to run at the upper limit of the product option
selected. 
On the first day of operation, DLM will intervene  if  severe instability is detected. 
Otherwise, DLM will wait until the day after provision before  deciding if it must
intervene, provided that the line has been trained up for at least 15 minutes during the
preceding day.
If DLM intervenes it will set a profile with a maximum  rate  and  a minimum rate,
where  the minimum rate  is  set at approximately half of the maximum rate
.  The
purpose of the minimum rate is to ensure that the line does not train at a rate which is
significantly below the level the line should be able to achieve.  If this happened, then
the line is likely to remain at a very low rate until a re-train is forced by the user by
powering off the modem. 
Note : It is the DLM system that sets the line profile, and this should not be interfered
with by CPs/users setting rates, SNR margins etc. at the modem. 
Note  : The upstream throughput is also constrained on the DSLAM to the upstream
rate requested in the order, i.e. 2Mbit/s, 10Mbit/s or 20Mbit/s, so even if the VDSL2
upstream line speed is higher, the  upstream throughput is constrained to the level
ordered for the product.

I can see that there may be an element of confusion between the established Profile (band) and Banded speeds that occur on 21CN ADSL (when there has been a fault condition and if it were not for the Banding the speed would be higher).
Certainly in your case you aren't achieving the higher speed of the Profile your are on, so not restricted. It should be noted that if your current  sync speed is actually lower than your line may be capable of, if the DLM sees a stable low enough error connection, it will raise the speed. It does seem better at doing this than 21CN ADSL DLM, judging by reports that other users have made.
Muttley62
Grafter
Posts: 130
Registered: 22-03-2013

Re: Banded profile FTTC

Thanks very much Anotherone for the explanation, that makes things much clearer now.