Towards bottleneck identification in cellular networks via passive TCP monitoring

Abstract

The bandwidth demand of today's mobile applications is permanently increasing. This requires more frequent upgrades of the mobile network capacity in the radio access as well as in the backhaul section. In such quickly evolving scenario, the risk of capacity bottleneck is increased, therefore network operators need tools to promptly detect capacity bottlenecks or, conversely, validate the current network state.To this end, we propose to exploit the passive observation of individual TCP connections. Being a closed loop protocol, the performances of every TCP connection depend on the status of the whole end-to-end path. Leveraging on this property, we propose a method to infer the presence of a capacity bottleneck along the path of an individual TCP connection by passively monitoring the DATA and ACK packets at a single monitoring point. We validate our approach with test traffic in a real 3G/4G operational network. The realized monitoring algorithm offers a powerful tool to network operators for on-line performance assessment and network troubleshooting. © 2014 Springer International Publishing Switzerland.