>> re-connect by it's self and continue to do this and on other connections the customer will have to manually re-boot the router for the connection to come back up.
I've seen this before, and its been discussed on these forums before by several people. In fact Ive even seen it occur on my own line with a different router. I've seen someone blame the ISP, but then move to another and the problem just followed.
My own (unproven) theory is that it may be either to do with the type of equipment in the exchange or at the RAS. Reason being that it first happened to me (with a Voyager 2100) after I'd been reRASed a few years ago. The problem went away entirely on its own accord about a year later.. which would have co-incided to about the time BT installed some new MSANs in our exchange.
I believe its more likely to occur when just the PPP session is lost (The later part of the connection to the ISP) rather than full loss of sync.
>> Another thing i think maybe related is i have read somewhere if the Router is passing a huge amount of traffic with high errors they Draytek will try to resync to kick out the errors.
No It will loose sync when the SNR is too low for the router to "hear" the signal properly.
Errors could be taken as being an early warning that the SNR is getting too low and is the equivalent of the router saying "pardon - can you repeat that please".
Thats the simple version, the reality is there's different types of errors, some of which are reported on some, but not all routers. The errors recorded by most routers are FEC/HEC/CRC, which are in effect the least severe.. the more severe error states are things like OOCD or LOF which leads up to an LOS.. which may lead to a full resync
If the router doesnt display these events, then you should be looking at the no of errored seconds over x period of time. The connection should be able to cope with occasional errors, but it will loose sync if there's a high burst of errors together. (eg too many CRCs in a time frame will be the trigger for one of the error state processes.. then 10 SES's will cause loss of sync). (
More info on the types of errors and error states ).
>> Also i would like any feedback on routers that are known to handle poor quality lines and low SNR signals.
hmmm bit of a hard task.. there are some routers which are known to handle poor quality lines. Some work better on some lines, whilst others work better on others.
For example some Netgears (DG834Gv4) are known to hang on well to long lines, whilst Speedtouch routers hang on well on others. Other routers worth looking at 2Wire and Roseways had success with the Billion 5200G.
When youre talking about poor quality - does that mean long lines with low sync speeds, or lots of SNR fluctuation?
Im also thinking that because of the VoIP element lots of errors aren't going to be too good as quality of call would be an issue so perhaps a router that can be tweaked to allow a higher Target SNR for stability. Im not well up on "true" VoIP so maybe others can comment.