 Multicast Push Technology Delivers The Real Thing
Most of the current crop of push products, including the ones we reviewed here, don't actually push data across the network. Instead, they use a client-initiated pull to download data from push servers or Web servers. This pull usually occurs over a predefined time interval.
Emerging IP multicast push products do push data across the network from server to client. With multicast push, a single server sends data to many clients in a single transfer whenever the need to push information arises, so clients can act on the data in real-time. This type of solution requires less bandwidth and offers event-driven, real-time data and information updates. This method is particularly well-suited for an intranet, where bandwidth
constraints are often an
issue and network administrators can ensure that network routers, switches and NICs are multicast-enabled.
Multicast push solutions use proprietary protocols on top of User Datagram Protocol (UDP) to ensure reliable corporate information delivery. For example, Starburst Communications Corp.'s Multicast File Transfer Protocol (MFTP), which runs over UDP, breaks a file into blocks and frames, which the server sends continuously. If the server receives negative acknowledgments for any data frames (because one or more clients didn't receive them), it transmits another pass of all missed frames and repeats the process until no negative acknowledgments are received.
MFTP will be used in the next release of Microsoft Corp.'s Netshow to push files that complement multicast audio and video transmissions. MFTP is also being incorporated into enterprise software delivery and management systems, such as Microsoft's System Management Server and PLATINUM technology's AutoXfer, to enable multicast push of software a
pplications and updates across the Intranet.
TIBCO, a decade-old middleware company, also uses IP multicast with a proprietary protocol over UDP that provides reliable multicast transmission. Unlike Starburst Communication Corp.'s emphasis on efficient and reliable file transfer, the TIBCO protocol is tuned for live, continuous information feeds and has programming interfaces for C, C++ and Java. This TIBCO multicasting middleware solution has been used for several years to stream data within large financial firms.
Several push vendors, including BackWeb, Diffusion and First Floor, are looking to leverage TIBCO's multicast technology to quicken information updates, while reducing intranet strain. While you may not be inclined to purchase and deploy TIBCO technology directly, you can expect to find the TIBCO core technology integrated into several new push products.
|
RSS
