Since a week ago I have huge spikes in counter-strike and got very high choke-values when I have them (normal 0, sometimes 1, when I have a spike up to 23)
Down- and upload rates go down to min. 7.5
Does anybody know how it comes/how to fix it?

Hm still missing an edit-button :/
After setting an MTU-value (1492) I got a max choke value of 1, but spikes with high loss-values -.-

the same is happening with me two :(

Ok after a lot of searching I found the following answer in a german forum:
High cl_rate and cl_updaterate can cause choke = procentual loss of the data which has been sent from the server to the player.
So if lan-settings (rate 25000 updaterate 101) cause choke-spikes u should use lower ones, hope that can help you ^^
Unfortunatelly I get loss-spikes when I do so (but I have no exeptional choke values anymore xD)
cmd_backup is supposed to help against loss, I'm gonna try that...

yeah my cl_rate and cl_updaterate are high... i'm gonna lower them down to see if it changes anything :)