Research On In-network Congestion Control Mechanism For NDN

In recent years,with the rapid development of the Internet,the amount of data in the network is increasing dramatically.Consequently,users had shifted their attention to the Internet content.Challenged by this change,the traditional end-to-end TCP/IP architecture has been unable to meet the requirements in the big data era.Named Data Networking has emerged quietly to make up for the shortcomings of traditional network,and has become the hotspot of the research of next generation of Internet.NDN adopts the mechanism of distributed caching and named routing,which effectively improves the ability of data distribution in the network.However,due to the existence of multi-source and multi-path phenomenon,NDN is still suffering the problem of network congestion.For its novel architecture design,the traditional congestion control mechanisms of TCP/IP cannot be applied to NDN directly.Therefore,how to design effective congestion control scheme for NDN has become an important research point.Facing the congestion control problem,the existing schemes are mainly divided into two types: receiver-based congestion control and inner-network-based congestion control.The former is mainly to control the request rate of receiver,so as to reduce the network traffic transmission.However,the congestion state estimate of receiver-based congestion control is inaccurate,because the estimate is only depended on the performance of the client.The latter is deployed in the routers,and can better coordinate and control the flow in the network.Therefore,this paper selects the in0 network congestion control as the solution,and then explores the NDN congestion control mechanism from the two aspects,resource utilization and client service quality.The main contributions of the paper are as follows.First,whether network resources are fully utilized is an important standard to measure the performance of network.For an excellent congestion control mechanism,it should maximize the utilization of network bandwidth under congestion.Guided by this idea,this paper proposes a BBR-based hop-by-hop congestion control mechanism,named BBR-HBH in short.On the one hand,this mechanism divides the process of multi-hop transmission into multi-segment single-hop transmission,and independently detect the actual bandwidth and RTT of each link with virtual interest packets.On the other hand,bandwidth coordination mechanism is designed to overall schedule the bandwidth resources of each link,which can maximize the utilization of bandwidth resources.The simulation results show that BBR-HBH can be effectively applied to NDN.Comparing with ICP mechanism,it greatly improves the bandwidth utilization when congestion is occurred.Second,considering that the existing congestion control schemes cannot effectively guarantee the QoS of VIP users when facing congestion,this paper proposes a congestion control mechanism based on identity authentication for Named Data Networks(IACCM).In IACCM,the network uses the identity of user to control the access of network traffic.It is divided into two parts,permission application and traffic access control.First,the user needs to send his public key and identity information to the network server provider(NSP).After receiving the user's application information,NSP uses his own private key and the user's public key to generate special identity credentials,which is returned to the user through a secure channel.At the same time,NSP also needs to pre-configure its own private key on the edge routers for verifying user identity.Later,before sending interests,users re-encrypt the identity information with their own private keys and identity credentials to generate a digital signature.When received interests,routers use the preconfigured NSP's private key to verify the identity of interests sender.According to the congestion levels,the interests of authorized users are forwarded preferentially,and the interest of unauthorized users are probabilistically accessed.Simulation results show that,compared with the ASFP mechanism,the authorized users under the IACCM have better performance in the interest satisfaction rate,interest packet retransmission rate,round-trip delay,and bandwidth occupancy rate.And it shows high adaptability when network state dynamically changes.