Chasing higher sync - Speedtouch 546

Hello. I have a speedtouch 546 v5 runinng firmware 5.4.0.11.0.

I'm posting because for months now my sync has remained stable at approx 5240. During this time I would see swings in SNR from 8 - 13. This suited me fine, I don't need the higher sync - I game a lot & prefer uninterrupted connectivity. Recently the 546 has been chasing higher sync values, for example I'm currently sync'd at 6336 with an SNR of 9. and have had approx 20 resets over the last 3 weeks, none of which have dipped below 5440.

I have not changed anything on the router & it's not like I sync at dire speeds - so I've ruled out a line fault. My BRAS profile is fine & I get acceptable DL speeds (generally 525KBs). Could something have changed in the exchange? Do I need to upgrade my firmware to 6.1? How have others here got on with the new fimware? Any other ideas, please?

Thanks for your time.

It could just be simply due to your line having less interference now - maybe something along your line' route, or within you or your neighbour's premises, that was previously causing more noise on your line, is now not switched or on causing interference.

Thanks Hysteria - appreciate your input & I hear what you're saying, however I've always been able to force the higher rate by instigating a manual re-sync. I simply chose not to because I knew that in doing so, when the SNR dips, I would eventually end up at my 'normal' rate anyway (usually in the evenings). I'm not seeing any more or any less SNR & my DMT tool reports much the same spread across the various frequencies.

Now though the 546 seems to have taken on the re-sync task when IT decides!

I upgraded from a Netgear DG834 (v1) for just this very issue. It always sync'd higher, but it didn't offer the stability I need. Nothing quite beats a re-sync mid frag!

Modems don't resync automatically just to get a higher speed. What's probably happening is that something is causing 'bursts' of noise that are enough to cause the modem to lose sync, but have gone by the time that the modem resyncs.

I would suggest that you need to take the usual noise avoidance measures. Does the problem disappear if you leave the modem connected to the master test socket?

Thanks for the replies.

I am currently connected to the Master socket. Interesting idea about the noise bursts - any idea what could cause such a short burst that the MODEM never syncs at a really dreadful speed, please?

I though that MODEMs operated within specific SNR regions, outside of which they would resync? Of course, this is simply a 'thought' :-)

EDIT: any thoughts on the latest firmware, please?

Edited by kalisana (Sat 10-Mar-07 17:01:02)

It only takes a short burst to knock out your connection such that by the time the modem has started the reconnection routine with the exchange, which is not instantaneous, the noise burst will have gone and so it will try to connect at the best sync it can for the SNR margin present at that moment.

Damn, looks as though I may indeed have a noise hunt on my hands.

Thank you everyone for the pointers, much appreciated.

EDIT: any ideas as to what might be generating the very short noise bursts, please?

Something else I've noticed - it only ever resyncs when the SNR margin is very low, i.e. 4-5. I accept this as normal behaviour as this margin has always forced a resync. It never loses sync with normal SNR margins (8-11).

I guess I need to monitor SNR and see if I get any dips when running 'normal' values. Although these may be hard to detect if the bursts are very short?!

Edited by kalisana (Sat 10-Mar-07 18:20:08)

Unless you can relate it to something electrical switching on or off at your place or externally when it actually happens not really. As these type of noise bursts can be a real pain if not downright impossible to locate unless it turns out to be something obvious as it could be at your place or anywhere between you and the exchange.

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any ideas as to what might be generating the very short noise bursts, please?

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Could be from all sorts of sources, but a common one is a noisy switch contact.

Connecting to the master socket is not enough - you need to try the test socket after removing the master face plate, assuming it has one. This disconnects the extension wiring. If the problem goes away then it's your extension wiring that's picking up the noise. If not then there's probably not much you can do about it other than asking your ISP to raise the margin.

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I am currently connected to the Master socket. Interesting idea about the noise bursts - any idea what could cause such a short burst that the MODEM never syncs at a really dreadful speed, please?

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Central heating pump, deep freeze, refrigerator or vacuum cleaner being switched on. The initial inductive load of even a modestly powered electric motor is quite impressive. Anything which causes you to hear a click on a radio could be enough. And that is just the stuff on your own mains circuit. Outside your home there are thunderstorms and the neighbourhood factory which turns heavy plant on and off all day and night. And don't forget the street lamps - if you find your line dropping just after sunset, they would be a prime suspect.