API Response time verdammt hoch

#Exectued on a netcup server, ping and down-/upload speeds are normal
time curl -H "Content-Type: application/json" --data "@test" "https://ccp.netcup.net/run/webservice/servers/endpoint.php?JSON"
{"serverrequestid":"222DM2jojzy2VJIQn39U2RllGJM","clientrequestid":"","action":"login","status":"success","statuscode":2000,"shortmessage":"Login successful","longmessage":"Session has been created successful.","responsedata":{"apisessionid":"***************************"}}
real    0m27.281s
user    0m0.020s
sys    0m0.004s

{
   "action":"login",
   "param":{
      "apikey":"xxxxxxxxxxxx",
      "apipassword":"xxxx",
      "customernumber":"123456"
   }
}