Mac OS 10.5 is here but no SSM support

Well Apple latest operating system, Mac OS 10.5 (codename Leopard), is finally here but unlike Windows Vista, there does seemed to be any Source Specific Multicast support added.

There is no sign of the Multicast Source Filter API (RFC3678) in the /usr/includes directory. Search for MCAST_JOIN_GROUP or MCAST_JOIN_SOURCE_GROUP on Build version 9A581, doesn’t return any results. So no IGMPv3 or MLDv2 for Mac OS X…

Additionally IPv6 stack still seems to be based on a very old version of Kame:
sysctl net.inet6.ip6.kame_version
net.inet6.ip6.kame_version: 20010528/apple-darwin

Very disappointing Apple :(

ssmping Looking Glass 0.3 released

I have just completed a new version of the ssmping looking glass - version 0.3. The main feature in this new version is added support for mcfirst - Stig’s tool for displaying packets received on a chosen multicast group and port. I have also added a ‘Raw Output’ mode that returns the raw output of the command executed.

The looking glass and its source code is available here:

MAST (Multicast Audio Streaming Toolkit) Released

The first public release of MAST was released today. MAST is a set of audio streaming tools using RTP over IPv4 and IPv6 multicast/unicast. Unlike VAT and RAT, which are designed primarily for audio conferencing, MAST is designed to be used for audio distribution and broadcasting. It is currently limited to receiving a single audio source, unlike RAT, which can mix serveral sources. It supports many of the audio payload types in the Audio-Visual Profile (RTP/AVP).

MAST is a re-write of pcm6cast, and now supports IPv4 as well as IPv6. Several new tools have been added, along with new codecs. There is now a dependency on the oRTP library, which is used to send and receive the RTP packets. RTCP is also now supported.

For more information visit the MAST Website.

IPv6 Multicast Address Calculator

I have just added a IPv6 Multicast Address Calculator to the musticast address tools section of this site.It prompts you for a multicast address type (transient, embedded RP, SSM), Scope and Group ID and it then calculates the full IPv6 multicast address for you.The tool is available here:

BBC Multicast Trial offers more radio streams

The BBC Multicast trial website has now split up TV and Radio into two separate sections and is offering links to a number of commercial radio stations, as well as BBC National and World Service streams.

Multicast streams from the following providers are now available:

  • BBC National Stations
  • BBC World Service
  • Virgin Radio
  • EMAP
  • GCap

A total of 34 multicast radio streams are now available.


There have been a number of multicast beacons developed over the years; dbeacon is the latest offering.

dbeacon is a Multicast Beacon written in C++. The main purpose of a beacon is to monitor other beacon’s reachability and collect statistics such as loss, delay and jitter between beacons. dbeacon support both IPv4 and IPv6 multicast, collecting information using both Any Source Multicast (ASM) and Source-Specific Multicast (SSM).

The difference between dbeacon from many previous beasons is that it is a peer-to-peer system - each host running dbeacon is equal and there is no master server. Each host has the option of running the web frontend to monitor statistics. Unlike previous beacons, dbeacon does not send out pseudo RTP packets and instead uses its own protocol.



SSMping is an excellent tool for checking multicast connectivity. Pings are sent back from the server using both unicast and multicast, so also confirms that the remote host is alive.

ssmping is a tool for checking whether one can receive Source Specific Multicast from a given host. If a host runs ssmpingd, users on other hosts can use the ssmping client tool to test whether they can receive SSM from the host. Another tool called asmping is also provided to check whether can receive ASM.


Sir Tim Berners-Lee Inaugural Lecture

Time: Wednesday 14th March 2007 @ 17:00 GMT

ECS-TV is proud to be the official provider of the much awaited inaugural lecture of Professor Sir Tim Berners-Lee at the University of Southampton.

The Lecture entitled “The World Wide Web: looking back, looking forward” provides a rare opportunity to see the inventor of the Web, hear his views on what he thinks of the web now and where this big part of everyday life is now heading.

Details of the IPv4 and IPv6 multicast streams are available from the ECS-TV website:

Net::RTP perl module

The Net::RTP perl module comes with a number of tools to test RTP multicast streams: