IT2032PAContent Management System (CMS) Nitec in Social Media & Web Technology
Mashup and Streaming ProtocolsIn this chapter, you will learn: o Define what is a streaming protocol o Describe the different type of streaming protocol use on the Internet o Outline the protocol issues o Identify the difference between portals and mashup
Streaming Protocol• A set of rules is used for establishing and controlling media sessions between end points.
Streaming Media Protocol• RTSP Protocol is the default protocol for streaming Windows Media. o Also used for streaming by: • RealMedia/RealVideo/RealAudio, • QuickTime video
Streaming Media Protocol• MMS Protocol is used for streaming Windows Media only. o RTSP using UDP is called RTSPU o RTSP using TCP is called RTSPT o MMS using UDP is called MMSU o MMS using TCP is called MMST
Streaming Media Protocol• PNM Protocol used for RealMedia/RealVideo/RealAudio streaming only.
Streaming Media Protocol• RTMP Protocol is used for Flash audio and video streams only
Streaming Media Protocol• HTTP Streaming HTTP streaming is a mechanism for sending data from a Web server to a Web browser in response to an event.HTTP protocol usually uses port 80 or 8080.
Streaming Media Protocol• MMS - Microsoft Media Services Microsofts streaming server uses the Microsoft Media Services (MMS) protocol (also called NetShow Services) to transfer unicast data.Note: o If WMP cannot negotiate a good connection using MMS over UDP, it will resort to MMS over TCP The default port for MMS is 1755
Streaming Media Protocol• RTSP - Real Time Streaming Protocol o use in streaming media systems which allows a client to remotely control a streaming media server o issuing VCR-like commands such as "play" and "pause", o allowing time-based access to files on a serverNote: o RTSP servers use RealNetworkss proprietary RDT as the transport protocol The default port for RTSP is 554
Streaming Media Protocol• PNM/PNA - o The first version of RealAudio o RealNetworks later switched to the IETF standardized RTSP o allowing time-based access to files on a serverNote: o RTSP servers use RealNetworkss proprietary RDT as the transport protocol The default port for RTSP is 554
Streaming Media Protocol• RTMP - Real Time Messaging Protocol - o Proprietary protocol developed by Adobe Systems o Stream audio and video to Adobe Flash PlayerNote: o RTMPE - secure RTMP protocol. Uses encryption. The default port for RTMP is 1935
Protocol Issues• User Datagram Protocol (UDP) – o send the media stream as a series of small packets. o simple and efficient o no mechanism to guarantee delivery o up to the receiving application to detect loss / corruption and recover data using error correction techniques o data is lost = stream may suffer a dropout
Protocol Issues• Another Approach – o HTTP adaptive bitrate streaming • files are very small, so that they can be compared to the streaming of packets
Protocol Issues• Transmission Control Protocol (TCP) – o guarantee correct delivery of each bit in the media stream o accomplish this with a system of timeouts and retries o makes them more complex to implement o data loss = media stream stalls while the protocol handlers detect the loss and retransmit the missing data
Protocol Issues• Unicast Protocol – send a separate copy of the media stream from the server to each recipient o norm for most Internet connections o does not scale well when many users want to view the same video
Protocol Issues• Multicast Protocol – developed to reduce the data replication and consequent server/network loads o send a single stream from the source to a group of recipients. o loss of video on demand functionality (downside). o But can be solved by elements such as • caching servers • digital set-top boxes • buffered media players
Protocol Issues• IP Protocol – sends a single media stream to a group of recipients on a computer network o used to manage delivery of multicast streams to the groups of recipients on a LAN o Challenge is routers and firewalls between LANs must allow the passage of packets to m’cast groups o Protocol Independent Multicast (Org has control) • can be used to deliver stream content to multiple Local Area Network segments
Protocol Issues• Peer-to-Peer (P2P) Protocol – arrange for prerecorded streams to be sent between computers o prevents the server and its network connections from becoming a bottleneck o raises technical, performance, quality, and business issues
Mashup vs Portals• Mashups & Portals are content aggregation tech Portal Mashup Older technology, Using newer, loosely extension to traditional defined "Web 2.0" Web server model using techniquesClassification well-defined approach
Mashup vs Portals Portal Mashup Split role of Web server Uses APIs provided by into two phases: different content sites to aggregate and reuse thePhilosophy / 1. markup generation content in another way 2. aggregation of markupApproach fragments Aggregates presentation- Can operate on pure XML oriented markup content and also on fragments (HTML, WML, presentation-orientedContent VoiceXML, etc.) content (e.g., HTML)dependencies
Mashup vs Portals Portal Mashup Content aggregation takes Content aggregation can place on the server take place either on theLocation server or on the clientdependencies "Salad bar" style: "Melting Pot" style – Aggregated content is Individual content may presented side-by-side be combined in anyAggregation without overlaps manner, resulting in structured hybrid contentstyle
Mashup vs Portals Portal Mashup Read and update event models CRUD operations are are defined through a specific based on RESTEvent portlet API architectural principles,model but no formal API exists Portlet behavior is governed by Base standards are XML standards JSR 168, JSR 286 interchanged as REST or and WSRP, Web Services.Relevant Portal page layout and portal RSS and Atom are functionality are undefined and commonly used.standards vendor-specific More specific mashup standards such as EMML are emerging.
Portals• Portals are older technology o designed as an extension to traditional dynamic Web applications Split into two phases o generation of markup "fragments" – portlet - hosted locally on the portal server or remotely o aggregation of the fragments into pages
Portals• Portals are older technology o defines a complete event model covering reads and updates o Portal technology is about server-side, presentation- tier aggregation
Types of Portals• Personal portals o a site on the Web that provides personalized capabilities to its visitors, providing a pathway to other content.
Types of Portals• Business portals o designed for sharing and collaboration in workplaces
Types of Portals • News portals o new media channels give them the opportunity to reach the viewers in a shorter span of time
Types of Portals• Government web portals o portal sites for citizens.
Types of Portals• Cultural portals o aggregate digitised cultural collections of galleries, libraries, archives and museums. .
Types of Portals• Corporate web portals o Intranets. (similar to business portals)
Types of Portals• Stock portals o Web-based applications that facilitates the process of informing the share-holders with substantial online data • latest price, • ask/bids, • the latest News, • reports • announcements
Types of Portals• Search portals o Search portals aggregate results from several search engines into one page
Types of Portals• Tenders portals o a gateway to search/modify/submit/archive data on tenders and professional processing of continuous online tenders.
Types of Portals• Hosted web portals o served simply as a tool for publishing information instead of the loftier goals of integrating legacy applications or presenting correlated data from distributed databases
Types of Portals• Domain-specific portals o specific to the particular domain, offering access to related companies and services