Two failing modems just before ADSLmax switch-on ... one big coincidence?

Towards the end of last week, our office ADSL connection starte
repeatedly losing sync ... looking at the modem's stats page reveale
that the SNR margin had become very low, and the line attenuatio
higher than it used to be. The modem there was a Dynamode R-ADSL-C4
which has a Conexant chipset.

The ISP did some line tests, which reported OK, and escalated th
problem to BT, and I bought a Philips SNA6500/5 from PC world a
lunchtime. Plugging that in produced decent SNR margin and attenuatio
figures, and the connection was rock solid again. I called the ISP t
say that it was just a dead modem, and to close the ticket.

That was on the Summertown exchange, SMSM.

Today I find my home connection is exhibiting exactly the sam
symptoms. I have the same model of Dynamode modem as the one at work
This is on the Boars Hill exchange, SMBZ.

Both exchanges are set for ADSLmax on the 31st. SMSM is amber, SMBZ i
green.

The question is: Is something being changed at the exchange end i
preparation for ADSLmax, which is causing these problems? Line car
firmware update?

It seems like a really big coincidence for two modems with the sam
chipset to fail within 5 days of each other, both exhibiting the sam
symptoms - of appearing to work fine, but reporting bad statistics o
the line. I'm planning to try a new modem on my home line soon, to se
if the problem magically goes away here too!

In the mean time, I'd be interested to hear if anyone else ha
experienced a similar sudden degradation of their line lately ..
perhaps it's time Dynamode et al released firmware updates for thei
modems to make them work properly with the latest exchange-sid
settings. Perhaps, though, I've just been unlucky with failing hardwar
over the last few days

--
gallafent

On 28 Mar 2006 22:48, gallafent wrote:

>The modem there was a Dynamode R-ADSL-C4, which has a Conexant chipset.

Thanks for the heads-up on this one. Although none of my friends or
family is actually using that particular modem/router (it's one I had
been considering, next time I saw one cheap on Ebay), I certainly have
or know of a few units which are running the Conexant chipset. Know of
a couple of Edimax units, 2 or 3 Safecom units, PTI/DabsValue units and
at least one which says "Conexant" on the admin web page :-) Will keep
a check on how they do when different exchanges get upgraded. These do
happen to be all over the place, from Staffs and S Wales to London and
Kent, but in most cases I expect my phone will ring first !!

>The question is: Is something being changed at the exchange end in
>preparation for ADSLmax, which is causing these problems? Line card
>firmware update?

Out of interest, is there anything in common with the exchange hardware?
I think some of the more recent firmware versions report the details in
the system log... From my sister's Safecom (in Staffordshire) it says

01/01/1970 00:00:19> Max Tx Power: -38dBm/Hz
01/01/1970 00:00:19> CO Vendor: TEXAS_INSTRUMENTS
01/01/1970 00:00:19> d/s SNR: 32.5dB, u/s SNR: 30.0dB

and an Edimax in S Wales

01/01/1970 00:00:17> Max Tx Power: -38dBm/Hz
01/01/1970 00:00:17> CO Vendor: TEXAS_INSTRUMENTS
01/01/1970 00:00:17> d/s SNR: 39.9dB, u/s SNR: 23.0dB

By chance, both show Texas Instruments
(CO = Central Office, which Americans use for telephone exchange)

My (pretty old) Conexant doesn't report the CO equipment, unfortunately,
but I did buy a few more routers recently for a quid or two each so one
or other might show this info... Unfortunately the single-port Safecom
doesn't seem to work over a remote link, else I'd check a friend's unit
elsewhere... the single port model seems to have a bug and goes to the
local LAN IP address in the URL, so while it is 84.xx.xx.xx from here I
click the "advanced setup" link and it goes to 10.0.0.100... and fails!

>It seems like a really big coincidence for two modems with the same
>chipset to fail within 5 days of each other, both exhibiting the same
>symptoms - of appearing to work fine, but reporting bad statistics on
>the line. I'm planning to try a new modem on my home line soon, to see
>if the problem magically goes away here too!

Yes - worth knowing, and a shame if it hits them all this way! Peter.

--
High quality e-mail... 10 GB mailbox 30 day free trial <http://2238.runbox.com> !

poster wrote:
> On 28 Mar 2006 22:48, gallafent wrote:
>
>
>>The modem there was a Dynamode R-ADSL-C4, which has a Conexant chipset.
>
>
> Thanks for the heads-up on this one. Although none of my friends or
> family is actually using that particular modem/router (it's one I had
> been considering, next time I saw one cheap on Ebay), I certainly have
> or know of a few units which are running the Conexant chipset. Know of
> a couple of Edimax units, 2 or 3 Safecom units, PTI/DabsValue units and
> at least one which says "Conexant" on the admin web page :-) Will keep
> a check on how they do when different exchanges get upgraded. These do
> happen to be all over the place, from Staffs and S Wales to London and
> Kent, but in most cases I expect my phone will ring first !!

My In Laws have got the Safecom 4110. About three weeks ago they
reported 'no broadband', just before disappearing on holiday.

I went to their house after they'd left, they'd left the Safecom
powered up. The ADSL link light was flashing, and the stats page
reported no connection (Atten and SNR fields were all 'N/A').

I rebooted, and it was fine again. I spent an hour or so on their PC
cleaning it up, and running Spybot upgrades etc, then suddenly the
modem lost link again. Nothing I could do restored it. I took it home,
and tried it on my line. It was fine (my line's SNR/Attenutaion is a
good deal worse than their's). I left it running 12 hrs, shut it down
for 12, and then running again for 48 hrs, all fine.

Re-installed it at the In-Law's and it was OK again there. I left it
running, and popped back in every couple of days to check. No problems.

The In Laws returned from holiday on Sunday, and all was fine until
last night, when they phoned to say the link light was flashing again.

I'm puzzled, could it be the Max ADSL upgrade upsetting it ?

Stats when working:

D/S U/S
Attn 42.4 22.0
SNR 24ish 31ish

Linked at 2 Megs d/s, 288k up.

Exchange Basingstoke THBZ

--
Mark
Please replace invalid and invalid with gmx and net to reply.

poster Wrote:
> On 28 Mar 2006 22:48, gallafent wrote:
> -I'm planning to try a new modem on my home line soon, to see
> if the problem magically goes away here too!-
>
> Yes - worth knowing, and a shame if it hits them all this way! Peter.
>

Hmm ... well, for the time being, at home at least, it is magicall
fixed with the old Dynamode modem too: today I have a solid connection
with SNR margins back up to between 25 and 31, and only a very fe
"errored seconds". So, I'm holding off buying a new one for th
moment.

Maybe it really was just a coincidence! Having said that, at th
office, one minute the Dynamode was consistently failing, and the nex
minute I plugged the Philips in and it was fine. I should test th
Dynamode at the office again ..... I expect it will work and I wil
merely have posted an example of some time-dependent variant o
Murphy's law. Ho hum

--
gallafent