BT Business Broadband ADSL2+ and Cisco 877

Hi,

I wondered if anyone can help.

I have been using BT Broadband for sometime now and from the very start I have suffered from an issue where I will loose connection for around 15 seconds, this could happen many times a day.

Looking at the Cisco logs, I see the following:
001186: Jan 31 18:31:32.812: %LINK-3-UPDOWN: Interface ATM0, changed state to down
001187: Jan 31 18:31:33.812: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, changed state to down
001188: Jan 31 18:31:46.988: %LINK-3-UPDOWN: Interface ATM0, changed state to up
001189: Jan 31 18:31:47.988: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, changed state to up

I have swapped the router, cable, filter etc no avail.

BT Wholesale have been looking at it and have done a "lift and shift", checked and replaced cabling. The engineers that have been say that interleaving should be switched off, other say it needed to be on so im not sure on that one.

My whole company uses Cisco 877's and BT Business Broadband all on the same code and they dont have an issue.

Looking at the config of one of the other routers the DSL operating mode is set to ADSL2+ where mine is set to itu-dmt. I tried setting my router to ADSL2+ but the connection doesn't stay up for more than a minute.

Any help would be appreciated.

Thanks

Gavin

Could simply be the line dropping due to noise.

Can you post your stats using the sh command?

Matt

Seen similar issues with Cisco 877's not taking to certain DSLAM chipsets. The lines were with Zen they said they'd seen some issues with certain makes of DSLAM's and Cisco kit, but no more details than tat.

Do you know what the remote chipset make is? You may have to connect another router to find out

Hi Matt,

Apologies for the long post but here goes:
ATM0
Alcatel 20190 chipset information
ATU-R (DS) ATU-C (US)
Modem Status: Showtime (DMTDSL_SHOWTIME)
DSL Mode: ITU G.992.1 (G.DMT) Annex A
ITU STD NUM: 0x01 0x1
Vendor ID: 'STMI' 'TSTC'
Vendor Specific: 0x0000 0x0500
Vendor Country: 0x0F 0xB5
Chip ID: C196 (0)
DFE BOM: DFE3.0 Annex A (1)
Capacity Used: 83% 100%
Noise Margin: 10.5 dB 6.0 dB
Output Power: 18.5 dBm 12.5 dBm
Attenuation: 41.0 dB 24.0 dB
FEC ES Errors: 0 0
ES Errors: 11982 75
SES Errors: 0 0
LOSES Errors: 0 0
UES Errors: 0 0
Defect Status: None None
Last Fail Code: None
Watchdog Counter: 0xC1
Watchdog Resets: 0
Selftest Result: 0x00
Subfunction: 0x00
Interrupts: 41642 (0 spurious)
PHY Access Err: 0
Activations: 65
LED Status: ON
LED On Time: 100
LED Off Time: 100
Init FW: init_AMR-3.0.014_no_bist.bin
Operation FW: AMR-3.0.014.bin
FW Source: embedded
FW Version: 3.0.14

Hi,

I dont unfortunately and I no longer have another router to try. I will try and find out and post back.

Gavin

Also need the downstream and upstream figures that go along with that data to make any real sense of it.

If activations means resyncs, then 65 suggests a noise issue.

Have you looked at the wiring in the premises? i.e. tested line from the master test socket? Got all phones/faxes/other devices filtered?

A handful of PoS kit which use phone lines can cause problems with broadband.

Also trying different versions of firmware can make a difference to both sync speed and other stability issues.

In reply to a post by theblarney:

Vendor ID: 'STMI' 'TSTC'

That could be the problem. The STMI chipset in your Cisco, isn't great. I'd really suggest benchmarking the line against something with a Broadcom chipset - even something as basic as a Speedtouch 536, just to see if that is any better.

Matt

Hi Mr Saffron,

The wiring in the premises is fine, my router is plugged into the master socket and has been checked by one of the engineers, I have even had a new cable from my house to the exchange (apparently).

As for the other devices, there is nothing else connected to the phone line.

Interleave Fast Interleave Fast
Speed (kbps): 6656 0 1056 0
Cells: 1131466 0 106951763 0
Reed-Solomon EC: 636 0 0 0
CRC Errors: 426 0 1 0
Header Errors: 362 0 4 1
Total BER: 6578E-10 0E-0
Leakage Average BER: 1123E-9 0E-0
ATU-R (DS) ATU-C (US)
Bitswap: enabled enabled
Bitswap success: 0 0
Bitswap failure: 0 0

Thanks

Gavin

I received a call from a very helpful chap at BT Wholesale who said that he was going to be the sole owner of the fault from within BT.

I mentioned again the ADSL2+ \ ITU.DMT configuration and the first thing he mentioned was a Cisco microcode update that were for a number of Cisco router models.

I have uploaded it to the router this afternoon and so have been able to change the router to ADSL2+ operating mode and so far so good the connection has been stable.

I will post back in a day or so my findings.

Agreed, an option if you find a router that handles the line better is to then use it as a pure modem, and use an appropriate cisco router to handle the security/routing