mcastproxy

When IP Multicast is not available the mcastproxy program can be used to connect hosts. Suppose that students from four different campi want to use TGWB. Suppose also that multicast is available in the local networks but it is not available among the campi. In that scenario, the mcastproxy program can be used to connect each campi. As shown in Figure , there is one instance of mcastproxy in each campus. Each mcastproxy instance can listen to local multicast traffic and send it unicast to each other campus. The packets received through unicast are sent through multicast to local users.

Figure: mcastproxy environment example

mcastproxy program uses a configuration file, mcastproxy.conf from the .tgwb directory located at user's home. Next is presented an example of this file.

#Multicast group address
GROUPADDR=225.1.2.3
#Number of hosts to send unicast packets
NADDR=2
#IP Addresses list to send unicast packtes
ADDRLIST
192.168.1.2
10.0.0.1
# Time to live for multicast packets
TTL=1
REUSEADDR=0
# Loopback: 1 enable, 0 disable
LOOPBACK=1
# Unicast port to use
UCASTPORT=32566
# Multicast port to use
MCASTPORT=5151