BT 2Wire/BT2700HGV dropping connection

[excossack]

Morning all.

I have landed here from the thinkbroadband forum.

ISP: Demon Internet
OS: Windows XP Pro sp3

I have a BT 2Wire/BT2700HGV router running Singtel branded firmware, the router will drop connection within a few minutes of being on or sometimes it can be a couple of hours.

I have a spare Netgear DG814 (which used to be my original router) before I went WiFi on a few devices. The netgear performs fine and does not drop connection like the 2wire does.
The DG814 does not connect at the same speed the 2wire does, the Netgear has a lower connection speed.

Some details from the routers
Netgear DG814
V4.10 Feb. 11, 2004 DG814

Modem
ADSL Firmware Version 3.9.122
Modem Status Connected
Connect Mode Fast Mode
Down Stream 4608 Kb/s
Up Stream 864 Kb/s
VPI 0
VCI 38

MTU 1475

BT 2Wire/BT2700HGV
2wire
Connection Speed:
• Incoming: 5706 kbps
• Outgoing: 1008 kbps
DSL Line (Wire Pair): Line 1 (inner pair)
Protocol: G.DMT2+ Annex A
Downstream Rate: 5706 kbps
Upstream Rate: 1008 kbps
Channel: Interleaved
Current Noise Margin: 9.1 dB (Downstream) 5.5 dB (Upstream)
Current Attenuation: 47.5 dB (Downstream) 23.0 dB (Upstream)
Current Output Power: 17.8 dBm (Downstream) -31.0 dBm (Upstream)
DSLAM Vendor Information: Country: {0xB5} Vendor: {50 00 00 00} Specific: {0x00}
PVC Info: 0/38


Singtel
BT2700HGV
• Software: 5.29.117.3

When the 2wire drops connection, sometime I see a red light on the router, other times I do not.
Here is the error that is shown in the diagnostics
DSL Synchronization: UP
G.DMT Signal: UP
PVC Connection: Could not find an ATM circuit
PPPoA Service: Unable to connect to login service
PPP Authentication: -
IP Connection: An Internet address could not be obtained
DNS Communication: Unable to contact the Domain Name Server

I have tried setting the MTU to the same as the Netgear and still get the same issues.

When the connection is dropped(or get a red light) as soon as I plug in my Netgear the connection springs to life and stays stable.

I have 4 WiFi connected devices, Wii, 2xSamsung phones and a XP tablet.
I have 2 wired connections
All devices experience the same issues.

The router plugs into a BT master socket with a built in filter which has a CAT5 and a RJ11? connection on the face plate

I have set the MTU Upload to 1475 and that made the router appear more stable , as a test I updated my news groups to generate some traffic, surfed the web and streamed some audio and all was good.

Later on that evening, it was up and down again.

Any ideas people?

Thanks
John

[Steve]

 

Not a 2wire user but I'm sure there will be some along later. However I believe the Singtel firmware has a minimum downstream noise margin of 8dB. The Netgear and the stock firmware for the 2wire will hang on to a much lower noise margin (0-6) before dropping connection.

[Lance]

Welcome to the forum.

It sounds like it could be a failing psu - the psu supplied with the 2700 does seem particularly weak. Spares used to be available on eBay or many people simply buy a whole new router so they have a spare one of those too.

[excossack]

Thanks for the quick replies. I may have a spare PSU from an old 2wire that fails to power up.

[Simon]

That could be why it fails to power up, though.  I've had three PSUs fail on one 2700. 

[Rik]

Another vote for probable PSU failure.

[Steve]

Except he's only got 1dB of margin to play with.

[excossack]

Is there a later firmware I can upgrade to that may help me?

[Rik]

Hang about, one of our 2700 experts will be along shortly.

[excossack]

For now, I have at least one option - change the PSU (assuming I havent binned the old one)

[Steve]

Just wondering whether routerstats would help? http://www.vwlowen.co.uk/internet/files.htm but whether it will differentiate the possible faults.

[excossack]

I shall have a look at the at link when I get home...The spooky thing is, that chap lives about 5mins from me!

[FritzBox]

Try the psu first, if it still does it then change the router

Had exactly the same problem with a m8's 2700 Singtel last week. Changed the psu, no joy. Stuck a brand new 2700 SBC firmware in, all is now well

[MisterW]

I agree with the others that the 2700 PSU is a weak link but I'm not convinced that it's a PSU failure in this case.
The log entry shows the DSL link UP but Authentication failing, even if the 2700 is rebooting due to PSU problems, why would it fail to authenticate sometimes ?
I'd be interested to know what mode ( G.DMT/DMT2/DMT2+ ) the Netgear is synching with?.
The 2700 is trying G.DMT2+, and at that attenuation ( 47db ) the line will probably perform better using G.DMT or maybe G.DMT2. I'm sure I've seen other instances of similar issues, where the 2700 is trying too hard to synch at G.DMT2+ and is sometimes failing to find an ATM circuit when synched. Not sure if it was just the singtel firmware though ? I must admit all of mine have BT firmware v5

[excossack]

I will have a look at the Netgear and see if i can see what mode its using.
Is this a limation of the hardware or the firmware that may cause the router to fail it it cant sync to the correct mode?

[excossack]

From the Netgear DG814 manual (dg814_reference_manual.pdf)

Interface Specifications:
WAN:
ADSL
Dual RJ-11 pins 2 and 3
T1.413
G.DMT
G.Lite
ITU Annex A

[MisterW]

G.DMT
G.Lite

Aha!, that tends to indicate that the DG814 is (G.DMT)ADSL1 only and nothing I can find contradicts this. That would explain why the Netgear synchs slower than the 2700. In principle there shouldn't be a problem with the 2700 synching using G.DMT2+ but at your attenuation its a bit marginal and if the DSL synch is at all 'iffy' I could see it failing to establish a ppp session.
Can you post the output from the DSL Diagnostics page ?

However I'm going to go back a bit on my suggestion that its not a PSU. My experience with failing PSU's is either rebooting or Red power lights but having spoken to one of my colleagues with a 2700 he had a PSU issue which caused a failure to connect, with it otherwsie looking ok ( i.e green lights ). So maybe changing the PSU is a good start after all...

[excossack]

Where is the DSL Diagnostic log located. I have found plenty of logs while looking around the router, so want to make sure I get the correct log.

[Rik]

http://192.168.1.254/xslt on my 2700s...

[excossack]

Great. Will have a look tonight. Standby for more Q's 

[excossack]

Ok, at the page http://192.168.0.1/xslt
I get the Gateway summary page showing these options

Internet Connect/Disconnect
Connection Status
Diagnostics
Wireless Setting
Voice Settings
User Guide


Internet Connection Details
Connection Type:    PPPoA
Username:    channel19.xx.xxx
Internet Address:    xx.xxx.x.xx
Subnet Mask:    255.255.255.255
Default Gateway:    194.159.169.245
Primary Domain Name Server:    158.152.1.58
Secondary Domain Name Server:    158.152.1.43
Domain:    
Maximum Transmission Unit (MTU):    1475
Gateway Ping:    Successful
DNS Communication:    Successful
Configuration Server Post:    Successful

[Rik]

Is Diagnostics a clickable link?

[excossack]

It certainly is, and that gives me the page
Links across the top:
Summary
Details
Diagnostics
Statistics
Advanced Settings

Status
DSL Synchronization:    UP
G.DMT Signal:    UP
PVC Connection:    UP
PPPoA Service:    UP
PPP Authentication:    UP
IP Connection:    UP
DNS Communication:    UP

With the option of Refresh or Test

[Rik]

Can you grab a screen shot and post it? It sounds very different to the firmware I'm running.

[excossack]

Ok will do. Give me bit.