Multicast

RFC 8815 deprecated interdomain PIM-ASM (any-source multicast) so PIM-SSM (source-specific multicast) is the way to go!

Setup

For it to work, you'll need to do the following:

  • Ask your peering to enable IPv4/IPv6 multicast AFI on your peering
  • Set up IPv4/IPv6 PIM for the (s,g) joins to pass through
  • Be prepared to setup IGMPv3 and MLDv2 from your listeners

You're done! You should receive the multicast routes from peers advertising them.

FRR configuration used by C4TG1RL5. Please make sure you understand how to configure and use frr before you use anything from this configuration!

Participants

Current participants:

  • NOP-MNT
  • GRAWITY-MNT
  • MIRSAL-MNT
  • C4TG1RL5-MNT
  • KIOUBIT-MNT
  • PREVARINITE-MNT
  • MARK22K-MNT

Feel free to ask for a peering and set it up!

Current streams

NOP music stream

cs broadcasts a 96 kHz, 24-bit music stream. An SDP file is required to receive it: 

v=0
o=Node 0 0 IN IP4 172.23.199.110
s=None
c=IN IP4 232.2.3.2
t=0 0
m=audio 1234 RTP/AVP 96
a=rtpmap:96 L24/96000/2
a=source-filter: incl IN IP4 232.2.3.2 172.23.199.110
v=0
o=Node 0 0 IN IP6 fd40:cc1e:c0de::fffe
s=None
c=IN IP6 ff3e::8232:232
t=0 0
m=audio 1234 RTP/AVP 96
a=rtpmap:96 L24/96000/2
a=source-filter: incl IN IP6 ff3e::8232:232 fd40:cc1e:c0de::fffe

The stream can then be streamed with ffplay -protocol_whitelist file,fd,udp,rtp -fflags +genpts /path/to/sdp_file.

mping

mping is a program that sends a ping message to a multicast group every second (and responds to incoming pings, if any). There are two implementations:

  • The original implementation by troglobit, which supports both sending and receiving.

  • A reimplementation, which supports only sending.

  • mcjoin -j -i [INTERFACE] [fd00:8e13:ce5d::9bee],[ff3e::8000:42]:4321 mping-sender