Pgm_Udp_Encapsulation


Used for:	RTclient and RTgms processes
Type:	Integer
Default Value:	`TRUE`
Valid Values:	`TRUE` or `FALSE`

The Pgm_Udp_Encapsulation option specifies whether multicast messages are encapsulated directly in IP or if they are encapsulated in UDP before IP encapsulation. TRUE specifies that the messages are to be encapsulated in UDP. FALSE specifies IP encapsulation.

UDP encapsulation makes each multicast message 12 bytes longer, but the RTgms and RTclients do not need to run as root on UNIX systems. RTgms and RTclients in a multicast group must have the same value for the Pgm_Udp_Encapsulation option. Messages that are UDP encapsulated do not benefit from the Cisco Systems PGM Router Assist feature.

If Pgm_Udp_Encapsulation is set to 1 to use UDP encapsulation, no PGM subscribers can be run on the machine where RTgms is running. This is because NAKs from PGM might not be correctly processed by the UDP protocol when RTgms and a PGM subscriber are running on the same machine. This problem does not occur when PGM is using raw IP sockets (Pgm_Udp_Encapsulation set to 0).