Yup, still using my somewhat antique 2600 which has been running 24/7/365 almost flawlessly since it was all shiny, new and state of the art ! Unfortunately my ISP has recently decided that I *really* needed an upgrade to 21CN and therefore swapped me over with no warning whatsoever let alone asking first and since then things have not been good

Previously it just sat in the corner doing its stuff and I haven't been near it let alone tinkered with it in donkey's years. I do however know from syslog archives that there hadn't been any problems to speak of. Line stats always stable/predictable (except when there's been a BT fault), PPP connections remain up for several 100 hours and are generally only terminated because I terminate them, very occasional dropped connections are re-established automatically, no loss of synch (except when there's a line fault), no significant errors and so on.

However, since being shoved onto 21CN I'm now getting a pretty unreasonable looking number of PPP drops. In some cases it's been a massive spike of uncorrected errors prompting the Vigor to drop the connection but mostly it's because of the other end suddenly failing to respond for no obvious reason i.e. no echo response. At no time is line synch lost or SNR reduced to an unacceptably low value. It's literally a case of everything working just fine and then suddenly nothing works and the Vigor is trying to re-establish a connection. The big problem is that on some occasions all attempts consistently fail and the Vigor will just sit there for ever trying every few seconds. The only solution is a power down and/or line disconnect for a period of time - possibly to clear a stale session that is preventing a new one being established. Logs appear to show spurious, strange, corrupt, illegal or otherwise unexpected responses whilst trying to re-establish a connection hence presumably why it keeps failing. Line stats are always good: Synch 8064K/448K, SNR is typically 14/15dB stable to 0.5dB and attenuation 23dB. Connections are obviously G.DMT (ITU G.992.1) but given the line stats, I've absolutely no idea why it doesn't synch at 8192K.

After a lengthy and still on-going debate/argument with my ISP who are insisting there isn't any problem of course, they're now trying to suggest that the Vigor is obviously incompatible because it's not shiny and new enough so that's clearly what's causing any difficulties there might be ! Almost certainly complete rubbish I think but does anyone have any thoughts or suggestions here ? I can't think of any plausible reason why it shouldn't work fine (as it had been for the best part of 10 years until the 21CN upgrade) and the fact that virtually all problems appear to be a result of no response from something downwind almost says it all. I can obviously post logs to show exactly what's happening but thought I'd ask if anyone knows of any likely/fundamental issues first before delving into the gory detail.

I can't offer a solution to your particular problem but I can say that my Vigor 2600VGi operated satisfactorily on my ADSL2+ service when my 2820 had to go off for repair. It's some time ago now and I can't remember whether I set Modulation to 'Auto' or to 'G.DMT'. If you haven't tried both settings, that might be worth a try.

Also, my ISP allows me (via the Control Pages) to remotely place the line into 'ADSL1' mode — I've never done this so I'm unsure whether the change is immediate or a request is forwarded to BT. However, the fact that such a facility exists for at least one ISP may be worth following up with your provider.

Good luck.

I've had problems with both 2800 and 2600 on 21CN.

Have used both on ADSL2 and Pipex's unbundled 16mb service and like you, massive up times. Migrated from pipex onto the recently installed 21CN with BT and it all went mad. Routers were losing sync and dropping connection. Sync rate plummeted, it was like being on a 56k modem, but it had more drops.

Went back and forth with the ISP. They reset sync profiles tweaked various settings. The connections eventually improved, but it was never very stable or fast. I ended up having to upgrade and tried both a 2820 and 2830 both which were massively better and am now back to getting a few hundred hours up time.

Very annoying to have to upgrade though when according to spec it should be ok.

AFAIK, the 2600 will only sync on ADSL2+ (21CN) lines at 8MB, if you can get it to sync at all. This is to do with the chipset and so no firmware upgrade is ever going to sort this out. I had 2 2600 and when one of my lines went to ADSL2+ I could never get it to work satisfactorily. It would sync (but at the capped speed on my short line)...

With your line attn you should be syncing way above that on an ADSL2+ service... in excess of 15MB I would have thought (presuming you are on an ADSL2+ up to 24MB service) - the SNR at 14/15MB shows there is serious instability on the line - probably caused by the frequent drops and the high number of uncorrected errors you're seeing.

I would suggest you look at an ADSL2+ compatible router - you can get a lot more out of this line..!

Thanks for the replies

The Vigor is happily working well most of the time and there has NEVER been a loss of synch and/or drop in data rate or IP Profile that I am aware of so it's obviously quite capable in general terms. The fact that someone has used one successfully under similar circumstances is good to know. However, the accounts of problems various are obviously not-quite-so-good to know !

The 2600 will only support G.DMT (ITU G.992.1) at best so yup, it's always going to be 8Mb absolute max regardless of what might actually be on offer but other than that I really can't see why there should be any major problems at all. Providing that the negotiation process with the current exchange equipment results in something truly compatible with ASDL1 rather than something else of course. I'm led to believe that this /shouldn't/ ever be an issue at all due to backward compatibility of ASDL2.

How (NOT) surprising to see the name BT cropping up in the discussion mind you seeing as they're not only my prime suspect here, they also appear to be tweaking stuff left, right and centre just now as well as apparently having some 21CN 'issues' that are being kept rather quiet it seems !

The thing is that I'm pretty sure that the primary problem is down to LCP non-compliance at the exchange equipment which is initially resulting in the PPP dropout and then subsequently screwing things up somewhat. This means that the link is sometimes ultimately hanging because neither end is behaving particularly sensibly when trying to negotiate a connection and/or login following a recently dropped connection. If the initial unexpected and unexplained drop didn't happen then the lock-up wouldn't happen either. The initial drop is due to a period of lack of response to routine control packets DESPITE both the link and the equipment at the other end apparently still essentially working as they should be. Something at the exchange or beyond appears to be simply ignoring incoming LCP packets for periods of time (1 to several minutes) as/when it feels like it for whatever reason it might have to be doing so.

Whilst I can well imagine that there may be various LCP packets in use now that the Vigor is not aware of due to it's age, let's face it, the protocol in general has been around since Noah set up his first network in the Ark and therefore it shouldn't be fundamentally broken !

Does anyone know if there's any way (via telnet) to tweak the Vigor Echo-Request settings and relevant timeouts ? In fact I'm sure that I used to have a *very* handy guide to all the telnet options/parameters but I'm b*ggered if I can find it now so any link to such a document would be very useful indeed. I'm currently struggling to remember how to telnet to it as it's been so long since I've needed to never mind being able remember or work out what I can and cannot do if/when I ever manage to get there :lol:

I totally understand that you don't want to shell out for new kit when you didn't ask for any change to your service, but the bottom line is that the 2600 is not ADSL2+ compatible (it never stated that it was in its specs). I guess if you're happy with the capped 8M speed and the frequent disconnects then so be it...

Personally (and this is just my opinion) I would retire the faithful 2600 and move on to something else that will give you the extra speed that your line could now so clearly achieve. I reluctantly (because I love the features that the 2600 provided and it was always rock solid) did just the same and now sync at 14500... My faithful 2600 is also now working as a simple switch, so it's still being useful !!