Understanding connection signals

[#1]

Can anyone attempt to give some advice about a broadband connection ?  This has nothing to do with Plusnet, except that you are all such helpful and friendly people !  As I have mentioned on this forum before, I have a place in France.  I have a broadband connection with Orange which I cannot use at present.  It is absolutely no good asking for help from the Orange Help Desk - this is France after all, where the word "service" is not in the dictionary and all I get is the Gallic Shrug !  I have tried reporting the problem, but to no avail.
The DSL lamp on the router is lit and stable, so to my pea-brain, that means that I should be connected, but I am not.  Npt even my internet radio, which is pretty fool-proof, cannot connect.  Now before I go into town to find the Orange office to rant and rave, I need to be sure of my facts.  Therefore, question :  Does the DSL light actually mean that the service is available and working, or does it just mean that the connection is alright ?
The router is showing a connection speed downstream of 615 and upstream of 105 - both slow, but we are a long way from the exchange out in the sticks and that speed is normal.  However, it is saying that the connection to the primary DNS server is "Fail" which suggests to me that there is a technical fault at Orange's end, but I really do not know.  I do not understand why I cannot connect if the DSL light is on, unless there is a problem with my computer (everything worked normally yesterday) or there is a fault with the ISP.
These are the test results translated :
Access Wi-Fi:  OK
ADSL connection Synchronization :  OK
Ping ATM OAM: OK
Ping ATM OAM complete: OK
Session PPP: FAIL
Authentification:  OK
Obtain IP:  FAIL
Ping default link:  FAIL
Ping Primary DNS Server:  OK
VPI = 8
VCI = 35
PPPOE
UBR w/o PCR
VC/MUX
So if anyone can tell me whether the DSL lamp is the detrming factor, I would be most grateful.  I wish that Orange gave as good service as I get from Plusnet at home in the UK.  The joke is that when you contact the Orange help desk, you are asked to fill out the customer satisfaction survey before you have even asked the question !! I think that says it all.
Thanks.

[#2]

What make/model of router is it?
Is there some sort of authentication/logon required - should be in the setup instructions?

[#3]

If there is a problem with the connection to the DNS server it won't be able to find any websites. You could try specifying a different server. Try 208.67.222.222 and 208.67.220.220 (OpenDNS).

[#4]

The router is a Hitachi AH4021.
I have also just found the following test result, in case it throws any light on the situation :
00:29:43 kern crit kernel: ADSL link down 
01:32:32 kern crit kernel: ADSL G.994 training 
01:32:39 kern crit kernel: ADSL G.992 started 
01:32:44 kern crit kernel: ADSL G.992 channel analysis 
01:32:48 kern crit kernel: ADSL G.992 message exchange 
01:32:48 kern crit kernel: ADSL link down 
01:2:52 kern crit kernel: ADSL G.994 training 
01:33:00 kern crit kernel: ADSL G.992 started 
01:33:04 kern crit kernel: ADSL G.992 channel analysis 
01:33:08 kern crit kernel: ADSL G.992 message exchange 
01:33:08 kern crit kernel: ADSL link up, interleaved, us=156, ds=604 
01:37:48 kern crit kernel: OAM loopback response not received on VPI/VCI 8/3
As far as authentification is concerned, I have been using the srevice for months already without having to change anything.  It suddenly stopped working early this morning following strong winds.  Thta is why I do not know whether it is me or whether it is the ISP.
I am not sure what was meant by "If there is a problem with the connection to the DNS server it won't be able to find any websites."  The DNS server is presumably at Orange's end.  Could that indicate that the DNS server is down ?  If only I could get them to tell me whether there is a general fault due to the weather it would help, but all they say is that they do not know !
I wish I understood what the stable DSL light really means.  By the way, my previous translation was not quite right; it should have read "Ping default GATEWAY : Fail"
Thanks

[#5]

Having the DSL light on and steady green means the modem has connected (synchronised) with the equipment at the telephone exchange. The next stage is to go on from there to your ISP (Orange). If that was successfully completed another light would normally come on, labelled Internet. Your failure to connect appears to be at that second stage.
The second stage needs your broadband username to be entered (for PlusNet in the UK that would be username@plusdsl.net) and the account password. All the configuration settings need to be correct; Orange should have told you what these are.
Note that the broadband username is *not* your email address. Sorry, I do not know what format this takes in France.

[#6]

Thanks for that; now I understand (except of course my modem here in France has no "internet" light on it whereas my Plusnet modem does !).
However, suddenly the system came back up, so obviously there was a problem which Orange could not be bothered to tell me about !  I can only guess that there DNS server was giving trouble, but it is miraculous that it all started up again without my doing anything - and still no further word from Orange.  Just another gallic Shrug, I suppose !
Thanks for all the help

[#7]

Forgive me if this is an egg sucking tutorial, but a web address of the form www.x.com is a virtual address. The DNS server has a big database of web addresses and tells your PC the actual IP address. It is a bit like the difference between a PO Box and a street address.
Your original post suggested there was a problem connecting to the DNS server, presumably Orange's own. Without a DNS server your PC doesn't know where to look to find the actual server a website is stored on. The fact it has suddenly come back would suggest it was a problem with their DNS server rather than your connection.

[#8]

Quote from: shermans

Session PPP: FAIL VPI = 8 VCI = 35 PPPOE UBR w/o PCR VC/MUX

I guess the DSL light means the VPI/VCI values are correct. But the PPP fail message tends to suggest the username/password you have for Orange is wrong or is not the username/password Orange expect to get from that line.
SW.

[#9]

Quote from: shermans

Session PPP: FAIL Authentification:  OK Obtain IP:  FAIL Ping default link:  FAIL Ping Primary DNS Server:  OK

Trying to guess what these really mean is difficult, but I imagine "Authentification:  OK" means the telecoms provider passed on the broadband username and password and the Orange authentication server accepted it. Then comes "Can we establish a PPP (Point-to-Point Protocol) connection please?" from your end and the Orange server didn't respond quickly enough (or at all). So Session PPP (and Obtain IP which follows) both fail and no connection was established.
I imagine the reason your connection has mysteriously started working again is because a nice person in Orange's Networks team has given their equipment a bit of TLC to sooth its fevered brow. I doubt that you are the only customer that will have been affected by these failures to connect.

[#10]

Thanks spraxyt for "smoothing my fevered brow" also !
You have answered my question, and I suspect your conclusion is correct.
Ironic, isn't it, that a Plusnet Forum solves the problems of another ISP. !  It says something about the Plusnet community and the service we fortunately get from Plusnet.