| 摘要 |
A Monitoring system and a method in a monitoring system comprising a public network 4, a private network 2, an access limiting device 6 arranged to limit the access of the private network 2 from the public network 4, and a control server 20, 22, 24 connected to the public network 4. The monitoring system further comprises a monitoring device 10 connected to the private network and being arranged to send an http request to the control server 20, 22, 24. The control server 20, 22, 24 being arranged to send a http response to the monitoring device 10 in response to the http request, wherein the content length of the http response is not defined or wherein the content length is set to a number that is large enough to enable transport of a plurality of future control messages as part of an over time stretched http response resulting in an open path from the control server 20, 22, 24 to the monitoring device 10 through the access limiting device 6 and wherein the control server 20, 22, 24 is arranged to send control messages to the monitoring device 10 via said open path. |
