Slow broadband

[#1]

Yesterday my broadband slowed down to 86Kbps and was like this all day. I tried to go through the steps PlusNet recommend but unfortunately I do not have a spare router and cannot access one.
This morning my speeds were fine, but they have deteriorated again, down to 486Kbps. I logged into the router and did a connectivity check on the Internet and I got a big red X for the Internet:

I have checked the connectivity a few times and sometimes everything is green and working, and other times I get the same result as the image above. Can someone advise what I can do to resolve this without the need to check with another router.

[#2]

I've just done a traceroute for community.plus.net if this helps:
concepts:~ macuser$ traceroute community.plus.net
traceroute: Warning: community.plus.net has multiple addresses; using 212.159.8.110
traceroute to community.plus.net (212.159.8.110), 64 hops max, 40 byte packets

1  dsldevice (192.168.1.254)                                                7.768 ms      99.702 ms      99.878 ms
2  lo0-central3.pcl-ag01.plus.net (195.166.128.234)          47.232 ms      47.039 ms      50.845 ms
3  gi1-5-131.pcl-gw01.plus.net (84.92.6.16)                        46.302 ms      46.637 ms      45.898 ms
4  po4.pcl-gw02.plus.net (212.159.1.129)                          60.336 ms      62.171 ms      308.444 ms
5  te2-2.thn-gw2.plus.net (212.159.0.190)                          59.594 ms      60.324 ms        59.283 ms
6  po4.thn-gw1.plus.net (212.159.1.134)                            60.922 ms      58.855 ms        59.315 ms
7  po6.ptn-gw01.plus.net (212.159.1.137)                          59.760 ms      60.543 ms        60.854 ms
8  gi3-0.pih-cr1.plus.net (212.159.1.177)                            60.547 ms      59.785 ms        62.807 ms
9  if25.pih-lb03.plus.net (212.159.0.17)                              61.538 ms      61.536 ms        62.404 ms
10  if25.pih-lb03.plus.net (212.159.0.17)                            61.855 ms      59.548 ms        59.793 ms

[#3]

Hi mentalist3d,
Both BT & our profile shows 7150k so I can't see anything obvious. Have a look here for some tips to troubleshoot the problem.
Jojo

[#4]

Hi Jojo
Thanks for the reply, I've had a look at that page and tested everything apart from the router (not got a spare) so I've submitted a ticket which is currently getting looked at, so hopefully it will be resolved soon or the problem identified.
Thanks