Meaning of "Link Control Failure" in router status

[#1]

I tried unsuccessfully to get an anwer to this in the ticket for a recent fault.

My broadband is aparently working but my router status still shows a "link control failure":

$ stt status
xdsl info
Modem state:                             up
Up time (Days hh:mm:ss):                 9 days, 18:01:20
xDSL Type:                               ADSL2+
Bandwidth (Down/Up - kbit/s):            4805/1190
{admin}=>
ppp iflist
Internet: dest  atm_Internet [link control failure]   [234:01:10]  retry : 10
    admin state = up    oper state = up    link state = connected
    flags = echo magic accomp restart mru addr route savepwd chap
    echotolerance = 5  mru = 1500    auth type = auto
        [user name = ********@plusdsl.net]
        [password  = ********]
    mode = IP numbered
    dns metric = 10  class = 12
    route : dst=0.0.0.0/0 - src=0.0.0.0/0 (metric 10)
    LCP  : state = opened  retransm = 0  term. reason =
    IPCP : state = opened  retransm = 0  term. reason = LCP down

What do the "link control failure" and "LCP down" messages mean, and are these anything to be concerned about?

I've tried to work this out myself. From what I've read, "LCP" means "Link Control Protocol" and is like a ping for PPP. The one that is down is listed against "IPCP" which is "Internet Protocol Control Protocol" but I don't know any more than that.

My connection is working despite the appearance of these error messages - I'm using it to write this!

[#2]

LCP down would normally suggest that the authentication has failed on our line, however as it's connected it's nothing to worry about. Are you using a router we provided?

[#3]

Yes, I am using a TG585v7 supplied by PlusNet.

[#4]

@Chris I just checked my router (a plusnet-supplied TG585 v7 with 8.2.6.5 firmware).

My service is up and working, status currenly showing 11 days' uptime. But I still see these two errors "atm_Internet [link control failure]" and "LCP down". However, I have just checked the router and the "internet OK" light is solid RED. Previously, prior to my recent line fault being rectified, this light would flicker on/off GREEN and RED would indicate the DSL being down.

So I am confused...