OpenPGM

From Developer Community

Development Status: Release Candidate 2.
Intended Audience:    Software Architects & Developers.
Platforms:            Linux: AMD64 & i386 (high resolution timers preferred),
License:              libpgm: LGPL license
                      libpgmplus (ultra-high performance version): GPL license.

Require a port on Solaris, AIX?

Need compatibility validation with Windows 2008?

Post on the openpgm-dev mailing list for questions, additional requirements, embedding, and support, or for commercial assistance see http://miru.hk/contact/.

OpenPGM is an open source implementation of the PGM specification in RFC 3208 available at www.ietf.org. PGM is a reliable and scalable multicast protocol that enables receivers to detect loss, request retransmission of lost data, or notify an application of unrecoverable loss. PGM is a receiver-reliable protocol, which means the receiver is responsible for ensuring all data is received, absolving the sender of reception responsibility.

PGM is appropriate for applications that require duplicate-free multicast data delivery from multiple sources to multiple receivers. PGM does not support acknowledged delivery, nor does it guarantee ordering of packets from multiple senders.

PGM is primarly used on internal networks to help integrate disparate systems through a common communication platform, the inherent danger of broadcast storms and quantity of traffic make this unsuitable for internet applications.

Current preferred platforms are Ubuntu 8.04 on AMD64, and CentOS 5.1 or 5.2 with the MRG real-time kernel. Tool chain support on RHEL 4 is insufficient for successful compilation.

Proprietary implementations of the PGM protocol include TIBCO SmartPGM (originally by WhiteBarn, bought by Talarian), Microsoft Windows XP/2003, IBM WebSphere MQ, and RT Logic's RTPGM. Network elements that provide PGM Router Assist are available from Cisco Systems, Juniper Networks, and Nortel Networks.

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File Releases

gstpgm.tar.bz2	-	2008-04-24
libpgm-1.0.0rc2.tar.bz2	-	2008-06-06
nightly	-	2008-03-25
opencv.tar.bz2	-	2008-02-09
opencv1.1.tar.bz2	-	2008-02-12
vlc-openpgm-patch.tar.bz2	-	2007-08-13

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Latest News

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CentOS 5.2

Support for the latest RHEL/CentOS supported platform is now bumped to 5.2. Upgrading from 5.1 is a simple yum update. Further details available in the CentOS 5.2 release announcement.

Other News:

Red Hat release version 1.0 of Red Hat Enterprise MRG.

--Steve-o 2008-06-25

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Ubuntu 8.04 and CentOS 5.2

The Build Library instructions have been updated for the recent Ubuntu 8.04 release. The latest RHEL/CentOS supported platform remains version 5.1.

RedHat have announced the release of RedHat Enterprise Linux 5.2, whilst the CentOS team guestimate a mid-June CentOS 5.2 release.

Other News:

Cisco announces an open source messaging protocol called Etch, no official details on cisco.com, but CIO.com details Etch beta release expected mid-July.

--Steve-o 2008-05-27

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Reed-Solomon Forward Error Correction

Forward error correction (FEC) provides two advantages, the ability to recover lost packets from extra redundant information sent with original data, and the ability to recover any lost packet with each extra parity packet. The cost is extra processing time calculating the redundant parity packets and regenerating lost packets.

The PGM protocol transport can elect to offer either or both forms of error correction together with regulation selective re-transmission requests.

Other News:

The MIT DARPA Urban Challenge Team published their Lightweight Communications and Marshalling (LCM) library. Similar to Rendezvous 8 it provides an in-process daemon but with basic subject naming, XDR message format, and optional reliability. APIs for C, Java, and Python.

--Steve-o 2008-03-18

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