## 1 Introduction
UIN is a promising schemes which has been evolved into Smart Identifier Network (SINET) [11; 12] and applied in multiple domains such as vehicular communication [13; 14; 15], satellite-terrestrial networks [16], wireless sensor networks [17] and smart grid [18]. Figure 1 shows the basic network architecture of UIN. As for infrastructure layer, it is composed by three planes including control plane, forwarding plane and user plane. The control plane consists of various control functions, and the basic UIN architecture mainly contains the Authentication Centre (AC) and IDentifier Mapping System (IDMS). AC is responsible for authenticating the attaching users, and IDMS is in charge of the mapping between AID and RID. The forwarding plane consists of access network and core network. The router in core network is called Core Router (CR) and adopts RID as the identifier, while the router in access network is called as Access Router (AR) and uses AID as the identifier. Therefore, there are two addressing spaces in UIN. The user plane consists of various user devices which attach to different access networks. Each device connected to access network will be assigned an AID, and performs the authentication procedure with AC at first. After that, IDMS will  
assign a AID-RID mapping relationship for authenticated devices. When packets transmit through the network boundary, IDMS will perform the identifier-location mapping management, and Access Switch Router (ASR) will encapsulate RIDs in the head of packets, which would be recognized by router in the core network for forwarding. In this way, massive changes are limited in access networks and the core network will remain relatively stable. The control plane and forwarding plane provide the control and forwarding separation mechanism, while the access network and core network provide the identifier and location separation mechanism. Compared with SDN which only separates the control and forwarding and ICN which only separates the resource and location, UNI provides better mobility, better security and better reliability through the identifier and location separation mechanism, access and core separation mechanism. The characteristics of UIN are useful for multicast to achieve the better manageable, controllable, and more security [19]. The essence of multicast is to deliver packets from one or more sources to a group of receivers. In general, multicast can be realized on network layer (IP multicast) or application layer. Compared with application layer multicast which provides multicast service based on unicast, IP multicast is designed to save bandwidth consumption of the whole network. The bandwidth benefit that multicast source could gain from IP multicast is huge, mostly from O(\(n\)) (\(n\) is the number of destinations in a multicast group) to O(1). After several decades of developments, IP multicast is very popular in specific deployments such as enterprise networks (e.g., for video conferencing), smart home networks (e.g., Universal Plug and Play (UPnP)), carrier IPTV and constrained environments [20]. Most importantly, with the recently fast development of IoTs, massive data from smart objects will be delivered to data centre to abstract the information and vice versa. Therefore, multicast communication plays an important role in this kind of applications. Currently, the most important IP multicast routing protocols are Protocol Independent Multicast (PIM) and its variants which includes Protocol Independent Multicast-Sparse Mode (PIM-SM) [21], Protocol Independent Multicast-Dense Mode (PIM-DM) [22] and Bidirectional Protocol Independent Multicast (BIDIR-PIM) [23], and all of them have been standardized by IETF. However, these multicast routing protocols are based on the open group model [24; 25] and adopt open group management mode through Internet Group Management Protocol (IGMP) [26] and Multicast Listener Discovery (MLD) [27], which cannot support the effective multicast group management for that sources have no control of receivers' access.