# A Single-Rate Multicast Congestion Control (SRMCC) Mechanism in Information-Centric Networking
## 1 Introduction  
Current network architecture and data delivery methods can no longer meet the demand for the efficient transmission of massive data in the future. Researchers are working hard on various supporting technologies, especially the optimization of network architecture [1]. A new network paradigm called information-centric networking (ICN) [2; 3; 4] has attracted wide attention. Unlike host-to-host communication in traditional IP networks, ICN is concerned with the content object itself rather than the location. Separating identity and location, ICN names information and uses the corresponding name rather than the IP address as identification for network traffic. Some ICN solutions have emerged. We are concerned with ICN solutions that can coexist with existing IP networks to achieve incremental deployment and smooth evolution, such as data-oriented network architecture (DONA) [5], MobilityFirst [6], information network (NetInf) [7], and (SEANet) [8]. In such solutions, a name resolution system (NRS) is used to map names to locators and requests are routed to the source based on the locator. To solve the problems faced in implementing these architectures, many related key techniques are still being investigated, such as naming, routing, caching, multicast [9; 10], security, and transport. This paper focuses on the study of multicast transport control techniques, more specifically the multicast congestion control mechanism. Multicast provides an efficient data transmission method, saving network resources through one-to-many and many-to-many transmission [11]. However, multicast itself does not consider how to deal with changes in network conditions and adjust the transmission rate. When a large amount of multicast traffic exists, the multicast source still transmits data at a fixed rate, which is bound to cause more serious congestion and packet loss. In addition, the multicast delivery stream may be widely distributed across the entire network along the multipoint delivery tree, and if the multicast application cannot respond correctly to network congestion, it will have a more serious impact on the network than the congestion caused by the unicast delivery application [12]. Moreover, the different branch bandwidths of the multicast delivery path and the heterogeneity of receivers make multicast congestion control very difficult [13]. The traditional multicast congestion control mechanism determines the sending rate according to the processing capacity of the worst-performing receiver, which is inefficient and unfair to other receivers. In ICN, some new multicast construction methods have appeared. But as far as we know, there is currently no effective congestion control mechanism that can be applied to ICN multicast. Therefore, it is necessary to study a congestion control mechanism for ICN multicast which can adapt to changes in the network environment and avoid major congestion. In this paper, we focus on designing an efficient single-rate multicast congestion control mechanism to improve multicast transmission performance. The main contributions of this paper are as follows:  
* We design a multicast congestion control mechanism called SRMCC in ICN. SRMCC provides router-assisted awareness of the network congestion state, a congestion control message (MCC) aggregation mechanism, and a single-rate adaptation method. To achieve protocol fairness, a fair shared rate estimation method is also innovatively proposed. * The single-rate adaptation method proposed in SRMCC adaptively adjusts the multicast rate according to the congestion state indicated by the queue occupancy ratio and introduces a rate selection factor to achieve a balance between packet loss rate and throughput. The definition of network congestion states is provided. * We develop and implement the SRMCC mechanism in NS-2 [14], and compare it with TFMCC, ASMP, and PerfwithECN.