Network packet

TCP Friendly Rate Control

Explicit Congestion Notification

Network congestion

Real-time computing

Retransmission

Computer science

Computer network

Flow control (data)

Hop (telecommunications)

Router

Queue

Cluster Computing

Data retrieval in Named Data Networking (NDN) is based on content names irrespective of their hosting location. The NDN architecture introduces original naming, forwarding and caching techniques to improve data delivery efficiency. These distinctive techniques make the TCP congestion control scheme not suitable for the NDN architecture. In particular, the in-network caching and the multi-path forwarding used in the NDN architecture lead to fluctuations in the Round Trip Time (RTT) measurements. This makes the Retransmission TimeOut (RTO) an unreliable congestion indicator. Thus, the congestion problem in Named Data Networks deserves to be reconsidered. In this paper, we present a new congestion control algorithm, called IRNA (Interest Rate Notification and Adjustment), to mitigate the congestion problem in Named Data Networks while maintaining per flow and per consumer fairness property. More specifically, IRNA is a hop-by-hop scheme where each router monitors the occupation level of its outgoing queues to detect in advance potential congestion events. When the queue size is above or below a preset threshold, the router sends explicit notifications to its downstream nodes to specify the appropriate interest rate. Hence, by cooperatively adjusting the Interest transmission rate of each node and for each flow, IRNA succeeded to provide a fair transmission. We evaluated the performance of our solution using ndnSIM simulations. We compared IRNA to state-of-the-art hop-by-hop congestion control solution and we proved that IRNA managed to provide a faster congestion reaction and to achieve per flow and per consumer throughput fairness while maintaining a good bandwidth usage.

Fair hop-by-hop interest rate control to mitigate congestion in named data networks