In order to get multicasting to work, one simply needs to understand the address scheme.
In general, the address range 224.0.0.0 - 239.255.255.255 are reserved for multicasting. Within in this address space, there are some base level operations in the 224.0.0.x range which shouldn't be interfered with.
For a single site, the address range between 239.252.0.0 and 239.255.255.255 is probably best.
Gstreamer and the current 40m network hubs are designed to handle this kind of communication already, so one merely needs to point them at the correct addresses.
While in /cvs/cds/caltech/target/Prosilica/40mCode/SnapCode type:
CamServe -F 'Mono8' -c 44058 -E 20000 -X 0 -Y 0 -H 480 -W 752 -l 0 -m 300 | gst-launch-0.10 fdsrc fd=0 blocksize=360960 ! video/x-raw-gray, height=480, width=752, bpp=8,depth=8,framerate=60/1 ! ffmpegcolorspace ! queue ! smokeenc keyframe=8 qmax=40 ! udpsink host=239.255.1.1 port=5000
This will multicast to the 239.255.1.1 address, using port 5000.
On the machine you wish to subscribe type:
gst-launch udpsrc multicast-group=239.255.1.1 port=5000 ! smokedec ! ffmpegcolorspace ! ximagesink sync=false |