A method for monitoring services, in a content delivery network (CDN), having a plurality of delivery nodes used to deliver services requested by end-users comprises: instructing the plurality of delivery nodes to associate identifiers to service requests, when the service requests arrive at any of the plurality of delivery nodes, the identifiers being logged with their associated service requests in log files; sending a request to a log collector for log information, the request including a service ID corresponding to a service to be monitored; receiving the log information corresponding to the services to be monitored, based on the service ID and the associated identifier; and based on the received log information, determining a required bandwidth for delivering the service to be monitored. Also, network nodes for carrying out this method are disclosed.