ADSL2+ slowdown after change of modem

willgoat · May 06, 2010, 10:35:13

Yesterday, i connected a new modem NETGEAR DG834 v4 on a shorter lead to my master socket. My speed drop down dramatically. Just now i check that i sync at a very slow speed for my ADSL2+. i used to get on average 21 mb/s, now i got 5.5 mb/s. I then check on bt speed check shown below.

Test1 comprises of Best Effort Test: -provides background information.

Download Speed
5454 Kbps

0 Kbps   7150 Kbps
Max Achievable Speed

Download speedachieved during the test was - 5454 Kbps
For your connection, the acceptable range of speedsis 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :6652 Kbps(DOWN-STREAM), 1056 Kbps(UP-STREAM)
IP Profile for your line is - 5500 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 11.24:23.62:65.14 (SBE:NBE:PBE)
These figures represent the ratio while sententiously passing Sub BE, Normal BE and Priority BE marked traffic.

the stats from netgear is shown below.

Port   Status   TxPkts   RxPkts   Collisions   Tx B/s   Rx B/s   Up Time
WAN   PPPoA   29463   43477   0    277   1677    06:16:27
LAN   10M/100M   279276   244863   0    1969   482    23:27:12

ADSL Link    Downstream   Upstream
Connection Speed   6655 kbps   1057 kbps
Line Attenuation    13.5 db   6.3 db

will this return to normal?
Noise Margin   32.0 db   5.3 db

Rik · May 06, 2010, 10:36:17

Not necessarily, what router did you replace?

willgoat · May 06, 2010, 10:42:02

Quote from: Rik on May 06, 2010, 10:36:17
Not necessarily, what router did you replace?

One of those plexus/tenda variety, WBR-T2.

Rik · May 06, 2010, 10:45:53

In my view you should be syncing much faster with those figures. If you made the change yesterday evening (when noise levels are at their highest0, then try re-booting. If not, try putting the old router back into use and see if that helps.

Steve · May 06, 2010, 10:50:30

I wonder if it's ones of those banded profiles looking at the sync,the limit for that band being 6656. BT tend to place those on unstable or high error rate connections

Rik · May 06, 2010, 11:02:48

IDNet can't get through to BT's system to check banding atm, so I can't give you a definite answer on banding, Will. If swapping routers or re-booting don't fix the problem, then give support a ring and they'll test for you.

willgoat · May 06, 2010, 11:21:32

Rik, I just put my old setup back on. Still synching at lousy speed.

ADSL Link Info

adsl: ADSL driver and PHY status
Status: Showtime Channel: FAST, Upstream rate = 1029 Kbps, Downstream rate = 66
55 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: U:OFF /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 32.9 5.0
Attn(dB): 19.5 5.7
Pwr(dBm): 17.7 12.4
Max(Kbps): 25876 19984
Rate (Kbps): 6655 1029
G.dmt framing
K: 104(0) 37
R: 16 8
S: 1 4
D: 64 2
ADSL2 framing
MSGc: 59 29
B: 103 36
M: 1 4
T: 2 4
R: 16 8
S: 0.4976 4.5714
L: 1929 273
D: 64 2
Counters
SF: 18293 18291
SFErr: 0 47014
RS: 2378106 310947
RSCorr: 0 369269
RSUnCorr: 0 0

HEC: 0 299157
OCD: 0 0
LCD: 0 0
Total Cells: 4643495 1194886503
Data Cells: 32610 558690525
Drop Cells: 0
Bit Errors: 0 13970177

ES: 0 2659
SES: 0 1695
UAS: 35 31523

please do check for me later on. thanks

willgoat · May 06, 2010, 11:23:29

and why is the SNR margin so high??

Steve · May 06, 2010, 11:29:29

If it's a banded profile the SNR margin will be high as you have the potential to sync much higher but the exchange won't let you. I'm just looking at your last set of stats your error count seems very high for such a short time up and they're upstream I think.

willgoat · May 06, 2010, 11:37:10

hmm.. before i put on the netgear, my upload speed is lower. after netgear on yesterday and when i switched back to the plexus now it still uploading at higher speed, maybe it is with higher upload profile for netgear or something.

so what should i do? leave the plexus (old) on or switch to the netgear setup, and wait?

Willgoat

Steve · May 06, 2010, 13:38:32

I am tempted to say Netgear as we're used to it and know it performs on adsl2+,I think probably best speak to support and find out what BT's done to the connection. You could ensure that you've taken all measures to reduce the interference at home, ring wire,flat extension leads and sky boxes are examples of devices that can induce noise into the adsl signal. We know adsl2+ is much more sensitive to the effects of noise than adsl. Does the Netgear a recent firmware?

willgoat · May 06, 2010, 14:37:29

I have updated the netgear to the latest firmware.

the thing is, with my previous modem which i have on for many months now on adsl2+, it didnt' have this low profile. So, just a bit surprised when the speed drop but so much. But i have been having problem with incoming call cutting off the adsl recently so i thought of changing modem to the proven netgear to check.

Steve · May 06, 2010, 14:50:48

I think you've now described your fault, with the loss of adsl with an incoming call and this has screwed your connection. Hopefully its just a filter (unless you've got a filtered faceplate) have you tried swapping it? The filters from adslnation are widely recommended. It something that you need to get corrected before sorting your connection speed out.

Rik · May 06, 2010, 15:18:45

I'd second that, Steve. Try a new filter and, if possible, use the test socket. Does your master socket have a part-removable faceplate, Will?

Rik · May 06, 2010, 16:49:22

Will

Support have now been able to check your line and, as Steve surmised, you are on a banded 3-6M profile. IDNet can get this lifted, but not until the problem of why the line is dropping sync has been resolved.

As mentioned, try a new filter, use the test socket if you have one, and try an alternative phone handset. If none of those steps cures the problem, get back to us and we'll think some more.

willgoat · May 06, 2010, 17:19:36

Rik, hmm...so you don't think this has anything to do with the netgear installed yesterday? Without the banded profile lifted, how would i know whether anything i did change anything since i will always reconnect back to the same limit? i might be a bit thick here ..

regards,

Rik · May 06, 2010, 17:26:01

It may have something to do with the Netgear, but it's more likely to be the result of perceived instability when the phone cuts off calls. Your line has a reasonably high error count so, taken with the cutoffs, DLM has judged it to be unstable and applied a banded 3-6M profile. You are running at the top end of that.

Find the cause of the problem before asking for re-banding as, if the problem persists, banding will be re-applied and BT will not remove it manually, so it will take some time to recover.

Steve · May 06, 2010, 18:11:32

I guess if you solve or alleviate the problem, your phone will stop cutting out your adsl and your overall error counts will reduce,if you wish to monitor your line 24/7 routerstats is a useful tool.

willgoat · May 06, 2010, 18:24:45

Rik, how do i check error with the netgear router?

Port   Status     TxPkts   RxPkts   Collisions   Tx B/s   Rx B/s   Up Time
WAN   PPPoA     1887     2373   0     284   1172   00:19:21
LAN   10M/100M     7207     6702   0     2636   834   00:23:25

ADSL Link   Downstream   Upstream
Connection Speed   6655 kbps   1085 kbps
Line Attenuation     14.0 db   6.4 db
Noise Margin     32.1 db   4.8 db

i checked the following:
1) on the old plexus modem setup, removed faceplate and connect straight socket in there. try phone call, still disconnect line.
2) switch to netgear with new line setup which consist of brand-new splitter straight to wall, and short 1m lead to netgear. incoming phone again caused disconnection.
3) switch the phone to my old analogue phone using a third splitter. incoming phone still caused disconnection.

so what do i do now?

Rik · May 06, 2010, 18:30:32

It's possible that you have a rare line fault called an HR (high resistance) fault. These are notoriously difficult to track. Ensure you have eliminated any possibility of your own equipment being an issue - that includes any internal extensions. If you're satisfied that is not the case, especially the filters, then ask support to get BT to test your line. Be aware, though, that if they send an engineer out who finds no fault, or a fault on your side of the test socket, you are looking at a bill of £170 or more.

Don't worry about the error count for now, the first thing we need to resolve is the line drops.

willgoat · May 06, 2010, 20:29:03

well, i am setting routerstat and observe it for the next few days. however, if the line continue to drop with answering of incoming call even with the low current profile, there is no point of keeping me banded at with such high margin..

see how it goes.

cheers.

Steve · May 06, 2010, 21:20:48

I agree it difficult to understand the reasons for banding but I think BT's attitude with unstable and/or high error rate connections is to keep their activity to a minimum. There are probably valid reasons for instance if you have a connection with high error counts with high throughput and sync,this connection will spend a lot of its time resubmitting data requests and thus consuming more than its allotted bandwidth over a period of time. Since BT relies on connections being unused some of the time(contention) the end result of this scenario is congestion and reduced throughput for others.

willgoat · May 12, 2010, 15:14:46

I am not getting any improvements, still disconnect after picking up a ringing phone. Since i got both my phone and adsl from IDNET, i suppose IDNET should be able to help me with this?

Rik · May 12, 2010, 15:24:37

Yes, contact support they will raise a fault.

Glenn · May 12, 2010, 15:27:47

Yes, you need to give them a call, ideally from a mobile or different phone number, as they may need to run more tests.

You seem to have done as much as you can to isolate your side of the phone circuit, eg using the test socket with different routers and filters, but still have the same issue.

It may well need an engineer visit, but as has been said before there is a potential for a charge if NFF, I haven't been charged for visits so far