A mobile ad hoc network (MANET) is a network which allows mobile nodes to communicate with other nodes in the absence of any infrastructure. It is a wireless medium where devices are connected by means of wireless links. Due to mobility and no fixed infrastructure, network congestion becomes one of the major drawback for both unicasting and multicasting in MANETs. Because of the network congestion, it is very difficult to guarantee quality of service (QoS) in MANETs. Issues like throughput, bandwidth, delay, jitter, etc. make QoS more challenging in such network. As multicast transmission in MANETs is much more complex and effective than unicast, so we will focus on the typical routing protocols based on multicast routing. Zone routing protocol (ZRP) is considered to be one of the most scalable routing protocols due to its multicasting feature. ZRP which is a hybrid multicasting routing protocol that solves the shortcomings of both proactive and reactive routing protocols. In this paper, we will discuss about the extended ZRP, i.e., MZRP (multicast zone routing protocol) for different multicasting approaches like shared tree-based (ST), dense mode (DM), center-based or core based tree multicast (CTR). Apart from these, in order to solve congestion due to multicasting, two vital queue management techniques are used namely, droptail and RED (random early detection) to analyze the performance of the network by means of QoS parameters like throughput, end-to-end delay, packet-delivery ratio and normalized overhead using MZRP routing protocol in MANETs.

mobile ad hoc network (MANET), multicast routing protocol, ZRP, droptail, RED.