All things related to multicast

[Frank Fulchiero <>]

On Jun 20, 2008, at 7:04 AM, Niels den Otter wrote:

> > I'm not sure if this is 'the bug', but I got an answer from the  
> > person
> that initiated the SAP stream yesterdam.
>
> He was setting up a miniSAP server (VLC) to announce a session via  
> SDR.
> This appeared to work too good. Problem was in the announcement
> interval. The documentation said that the announcement interval should
> be provided in seconds, while the sourcecode would have a
> usleep(interval) so in microseconds.

If that's true, that's probably how we caused the SAP storm in February.
But it's not always a consistent bug, as we ran it with a delay of 30  
for a whole day without problems:

# sap.cfg - Configuration file of the mini SAP server

# Global miniSAPserver options
[global]

# Number of seconds between announces. 5 is default. Internet  
announces better use 30.
sap_delay=30

# The network interface on which to stream.
interface=en0

# Then you should have one "[program]" section per program announced

# Note that only announces for MPEG2 TS streams are supported.
# Though announces of other types of streams may work for some clients,
# they will not be compliant to the announce spec. and are not at all
# guaranteed to work.

# IPv4 example
[program]
# Name of the program (as it will show up in the VLC playlist)
name=ConnProgram1

# Name of the streaming entity (organisation)
user=conncoll

# DNS or IP of the machine on which you run the stream
machine=136.244.96.102

# Website of the streaming entity (organisation)
site=http://www.conncoll.edu

# Multicast IP address of the program
address=233.88.214.137

# UDP Port
port=1234

# The name of the playlistgroup your announce will be part of in the  
VLC playlist
playlist_group=ConncollPlaylist