IT2032PA Content Management

System (CMS)Nitec in Social Media & Web Technology

Mashup and Streaming Protocols

In this chapter, you will learn:oDefine what is a streaming protocol oDescribe the different type of streaming protocol

use on the Internet oOutline 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 StreamingHTTP 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 ServicesMicrosoft's 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 Protocolo use in streaming media systems which allows a

client to remotely control a streaming media servero issuing VCR-like commands such as "play" and

"pause", o allowing time-based access to files on a server

Note: o RTSP servers use RealNetworks's 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 RTSPo allowing time-based access to files on a server

Note: o RTSP servers use RealNetworks's 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 Systemso Stream audio and video to Adobe Flash Player

Note: oRTMPE - 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 efficiento no mechanism to guarantee deliveryo 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 streamo accomplish this with a system of timeouts and

retrieso makes them more complex to implemento 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 recipiento norm for most Internet connectionso 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 loadso 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 networko used to manage delivery of multicast streams to the

groups of recipients on a LANo Challenge is routers and firewalls between LANs

must allow the passage of packets to m’cast groupso 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 computerso prevents the server and its network connections

from becoming a bottlenecko raises technical, performance, quality, and business

issues

Mashup vs Portals

• Mashups & Portals are content aggregation tech

 Portal Mashup

Classification

Older technology, extension to traditional Web server model using well-defined approach

Using newer, loosely defined "Web 2.0" techniques

Mashup vs Portals 

Portal Mashup

Philosophy / Approach

Split role of Web server into two phases: 1. markup generation 2. aggregation of markup fragments

Uses APIs provided by different content sites to aggregate and reuse the content in another way

Content dependencies

Aggregates presentation-oriented markup fragments (HTML, WML, VoiceXML, etc.)

Can operate on pure XML content and also on presentation-oriented content (e.g., HTML)

Mashup vs Portals 

Portal Mashup

Location dependencies

Content aggregation takes place on the server

Content aggregation can take place either on the server or on the client

Aggregation style

"Salad bar" style:

Aggregated content is presented 'side-by-side' without overlaps

"Melting Pot" style –

Individual content may be combined in any manner, resulting in structured hybrid content

Mashup vs Portals 

Portal Mashup

Event model

Read and update event models are defined through a specific portlet API

CRUD operations are based on REST architectural principles, but no formal API exists

Relevant standards

Portlet behavior is governed by standards JSR 168, JSR 286 and WSRP,

Portal page layout and portal functionality are undefined and vendor-specific

Base standards are XML interchanged as REST or Web Services.

RSS and Atom are commonly used.

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 phaseso 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

updateso Portal technology is about server-side, presentation-

tier aggregation

Types of Portals

• Personal portalso a site on the Web that provides personalized

capabilities to its visitors, providing a pathway to other content.

Types of Portals

• Business portalso designed for

sharing and collaboration in workplaces

Types of Portals

• News portalso new media channels

give them the opportunity to reach the viewers in a shorter span of time

Types of Portals

• Government web portalso portal sites for citizens.

Types of Portals

• Cultural portalso aggregate digitised cultural collections of galleries,

libraries, archives and museums. .

Types of Portals

• Corporate web portalso Intranets. (similar to business portals)

Types of Portals

• Stock portalso 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 portalso Search portals aggregate results from several search

engines into one page

Types of Portals

• Tender's portalso a gateway to search/modify/submit/archive data on

tenders and professional processing of continuous online tenders.

Types of Portals

• Hosted web portalso 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 portalso specific to the particular domain, offering access to

related companies and services