Miru Ships Standards Based Low Latency Open Source Messaging Software

Hong Kong - May 15, 2009 - Miru, Limited, a development studio of enterprise middleware and applications integration, today announced the immediate availability of OpenPGM, an open source low latency reliable multicast messaging software based on the standard for broadcasting information over an internet.

The transport technology standard, known as Pragmatic General Multicast, enables private networks and the Internet to handle more traffic by sending critical business information in a more reliable, cost-effective and bandwidth-friendly manner.

The PGM reliable transport protocol communications technology, which was designed by Cisco Systems and TIBCO Software, is registered with the Internet Engineering Task Force (IETF), the Internet standards body.

PGM enabled network devices, such as Cisco, Juniper, or Nortel routers, enhance the scalability and reliability of the technology by eliminating redundant traffic when recovering lost messages.

The initial general release is available for Linux and Solaris platforms on IA32 and x86-64 architectures and is wire compatible with Microsoft’s PGM implementation as available in Microsoft Windows Server 2003 and Microsoft Windows XP with Microsoft Message Queuing.

About IP Multicast

In computer networking, broadcast refers to transmitting a message to every device on the network, a one-to-many paradigm similar to television or radio. Multicast is a technique to only deliver to those recipients expressing an interest in the content. A multicast source is only required to send a message once, the network infrastructure takes care of replicating to each receiver as necessary. Conventional unicast applications require the server to send copies of the same message to each recipient.

Multicast does not guarantee reliability or ordering of messages. A recipient may receive messages out of order, duplicated, or missing with no notice.

About Pragmatic General Multicast (PGM)

PGM is a reliable multicast transport protocol developed by a range of vendors including Cisco and TIBCO and described in RFC 3208.

About Miru, Limited.

Miru is development studio specialising in building high-quality, open source multicast message orientated middleware systems. Miru also offers support, training and consulting services to its customers worldwide.
Learn more: http://miru.hk .


LINUX is a trademark of Linus Torvalds. MIRU is a trademark of Miru, Limited. All other product and company names and marks mentioned in this document are property of their respective owners and are mentioned for identification purposes only.

Flavours of Multicast

The reason why multicast is not prevalent on the Internet today is due to two main reasons, first is lack of support in network infrastructure.  Multicast is an optional part of the IPv4 protocol and so not every vendor has implemented support.  Second is filtering, as in what control is there over different parties sending data to any multicast group.  This is an issue as multicast uses a separate range of IP addresses for its communication of which is a limited number.

As an example, imagine the US President Obama’s inauguration is being being multicast live on the Internet, what happens if at the same time a radio station in New Zealand is broadcasting live news, the Hong Kong Stock Exchange is publishing stock prices, and Wembley stadium sending live match details from London?  The answer is a mess, wasted routing and link resources forwarding packets from all around to world to parties simply not interested.

This method of multicast, the default operation, is called any-source multicast (ASM), and is more suited to controlled environments such as private networks in which applications and network topology can be arranged to suit the expected usage and conflicts from other applications is not going to occur.

Source-specific multicast (SSM) was then created to limit the source of packets to a selected range of addresses.  This requires end-point router support, IGMPv3 for IPv4, and MLDv2 for IPv6, together with operating system support for the matching API and filtering without router support.