TCP STREAMING ISSUE? Please help

Question

HI 
Iam posting here as my last resort to see if one of the many experts can resolve the anomaly I have on my BT Infinity option 2 totally unlimted package.
The issue is streaming my slingbox a device which in the past has been sold in the BT shop .The slingbox is located abroad and  I have had BT infinity a few years now.
when I first changed to  BT I first had this problem connecting to the slingbox ,it used to buffers slightly  and the onscreen application give stats on the streaming speed which when streaming,The stats would show the speed to be going at 2.5meg speed and then have sudden drops to 1meg which interupted viewing now this did not happen all the time but was intermittent. At this point it is very relevent to point out all other appliations have  worked without any noticble issues.
Iam bringing this issue foward now because I have recently changed my work/shift patterns so I have weekends off and find myself at home on more evenings and therefore using this device more now from my Home broadband connection what I have noticed is that at he times Iam home the device not only has sudden drops but also struggles with the streaming speed 900kbps like there is restrictions on the type of data.
When I do the bt wholesale speed test my stats are Brilliant 73meg down      16meg up on further diagnostics the line ip profile is 75 meg and it all looks good.
However my BT infinity struggles with this application and struggles with streaming tcp on my slingbox which only needs 2.5meg to work flawlessly.
I have regulary connected to my slingbox through different ISP be it  where I worked {BE BROADBAND} .my freinds house {sky fibre optic} and my brothers house who is on adsl2 with o2 broadband and he still is and has not changed quite yet to the sky infestrucure because he requires static ip. At these premises the slingbox streaming works faultlessly.
That proves at least one thing that the problem does not reside at the source end.
So over the last month or so that has led me to investigate my connection and what could be the possible causes of this problem being with my connection only.
I have changed over from my BT router to top of the range LINKSYS 6700 changed wifi channels switched off wifi , connected 3 different laptops /pc via ethernet, disconnected all other devices etc and connected 1 PC at  a time had a new connection to my DP pole 14 months ago aswell as new internal wireing done by openreach. And the problems still persists more so at the evening and weekends.
The last thing I tried was Wireshark which gives information on whatever data is going through the system. I  ran the application on my brothers connection using slingbox and under the heading PROTOCOL it shows as TCP.
When i use wireshark at my connection under the same heading PROTOCOL its says HTTP and it says under the heading  INFO continuation or non HTTP traffic.
 I understand there maybe many under lining factors to why the application does not perform to the desired quality distance from cab , line etc but the reality is the device performs as it should do everywhere i have tried and my brothers who lives a few streets away laughs at me that he is on adsl connection and pays half the cost for his broadband but has alll his services working without issues. 
I have rang BT technical a few times and although the BT tech team have tried to help I have gone round in circles in basically restarting router or modem.
I do feel that maybe some sort of settings change from BT side will resolve this
My contract is due to end with BT at the end of March 2014 and with regret if this issue is not corrected then unfortunetly I will have to change ISP provider.
Thanks

Answer 1

Hi I followed tha link to GLASHOST and when you try to test it comes back that there has been a error ?
Is there another website I could try?
Also how do I contact the MODS, regardless to the website not allowing me to test, at certain times (evening) there is definately throttling occuring or some setting on my line is causing this issue ,Iam sorry but tried to phone the TECH team but apart from power down modem or router there has been no effort made to try and resolve the problem.
I need some one at BT with expert experiance and Know how to look into this thoroughly.
I phoned customer options team yesterday and requested my MAC as I have less thn 1 month contract remaining,however  I  do not want to leave BT its a repitable company that has been trading for many years and its time that they showed that to me. do they care if I LEAVE?