In this protocol evaluation, SReM is compared with Xcast+ protocol, the selection of Xcast+
is done for the following reasons:-
J Xcast+ is widely referenced in the area of explicit multicast protocols.
J The availability of a close implementation for Xcast+ on NS2, so a modification
for the available simulation is done instead of implementing this protocol from
scratch.
J This protocol (Xcast+) is relatively close to the proposed protocol (SReM), so the
comparison will give good indication of the performance of SReM.
4.6.2.2 Performance Metrics
The following metrics are used to evaluate the performance of proposed work:-
• Average Packet Header Size represents the size of the header included in the data
packet in bytes. It represents the size of each data packet header in order to
deliver this packet to all destinations.
• Average End To End Delay: is the average time that takes the data packet sent by
source node to reach its destination node.
Total end to end delay = SUM( time_received(pkt) - timesent(pkt)) for all data packets
Avg. End To End Delay (AED) = Total end to end delay / no. of data packets received
• Normalized Routing Overhead: represents the number of sent or forwarded
routing packets to the number of data packets received by the multicast group
member.
Normalized Routing Overhead = No. routing overhead messages / no. of data packet
received by multicast group members.
4.6.2.3 Simulation Results
The simulation results will be discussed in this section, this discussion is organized with
regard to the metrics used for protocol evaluation. At each part, the results are presented in
figure form and then a discussion and explanation for theses figures is mentioned.
92