>> Then it wouldn't reconnect to my ISP after resyncing again.
That bit is part of the establishing a PPP session. Sync is attained between you and the exchange, whilst the PPP session is the ISP part.* Your ISP can make you loose the PPP session but they cant make you drop sync.
I have actually seen numerous reports where users have problems automatically regaining PPP session after an ISP has carried out load balancing, or if the PPP session is lost for some other reason. As mentioned I know someone who moved to zen because he thought it was an isp specific problem but it followed him there too. Ive seen reports of Enta customers and also many other ISPs saying the same thing.
I even went through a period of it myself with my Voyager 2100 router which righted itself again out of the blue. I didnt have DMT installed at the time, nor did the guy who moved to Zen.
This problem seems to crop up with various different routers, it covers various ISPs and it seems to come and go, one thing I have seen mentioned elsewhere is that it doesnt seem to affect the ST frog modems, possibly because a USB modem will automatically sync when the PC is booted up, but relies on the "dial command" (PPP session) being initiated on the PC.
A router is a separate entity with its own processor, CPU and even operating system and doesnt need anything PC related to be able to attain sync or establish a PPP session and carries out this process without any interaction from the PC or anything on the PC.
All the DMT tool does is sets a command in the router so that it will establish a sync at a lower target SNR Margin during the sync negotiation process with the dslam and DLM. It doesnt actually amend anything at all to do with the PPP session.
Because a router doesnt rely on a PC related for sync or PPP then thats why I dont see how the problem could have "gone away" when a new PC was attached.
When I did have the problem the time frame did co-incide with a time when BT was "mucking about" stuff at my exchange,
and although I cant prove it, it is possible that it is far more likely to be something to do with a combination of the router hardware, the dslam and further up the chain at RADIUS servers which does have responsiblity for establishing a login.
Although it shouldnt in theory happen, there are many many cases when if the router chipset and the dslam chipset is "matched" then users seem to report better stability. Theres also the AR7 chipset "issue" which hasnt yet been fully explained, but its possible that that involves a specific combination of the router chipset and the dslam chipset and some other as yet undiscovered BT variant(s) on their config. If you match all those variants whatever they are then something weird seems to happen.
It cant however be anything PC related... hence why the change of PC etc is likely to be a co-incidence.
However just thought do you connect via USB or ethernet?
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Edited to clarify
* Although the PPP session is generally on the whole ISP related, there is an earlier part of authentication which is carried out still on the BT system.
Authentication is a many stage process, but can be split down into 2 main parts... at the BTw RAS and at the ISP's RADIUS.