2. Mashup and Streaming Protocols
In 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
3. Streaming Protocol
• A set of rules is used for establishing and
controlling media sessions between end points.
4. Streaming Media Protocol
• RTSP Protocol
is the default protocol for streaming Windows Media.
o Also used for streaming by:
• RealMedia/RealVideo/RealAudio,
• QuickTime video
5. 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
8. 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.
9. Streaming Media Protocol
• MMS - Microsoft Media Services
Microsoft'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
10. 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 server
Note:
o RTSP servers use RealNetworks's proprietary RDT as
the transport protocol
The default port for RTSP is 554
11. 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 server
Note:
o RTSP servers use RealNetworks's proprietary RDT as
the transport protocol
The default port for RTSP is 554
12. Streaming Media Protocol
• RTMP - Real Time Messaging Protocol -
o Proprietary protocol developed by Adobe Systems
o Stream audio and video to Adobe Flash Player
Note:
o RTMPE - secure RTMP protocol. Uses
encryption.
The default port for RTMP is 1935
13. 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
14. Protocol Issues
• Another Approach –
o HTTP adaptive bitrate streaming
• files are very small, so that they can be compared to the
streaming of packets
15. 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
16. 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
17. 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
18. 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
19. 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
20. 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 techniques
Classification well-defined approach
21. Mashup vs Portals
Portal Mashup
Split role of Web server Uses APIs provided by
into two phases: different content sites to
aggregate and reuse the
Philosophy / 1. markup generation content in another way
2. aggregation of markup
Approach fragments
Aggregates presentation- Can operate on pure XML
oriented markup content and also on
fragments (HTML, WML, presentation-oriented
Content VoiceXML, etc.) content (e.g., HTML)
dependencies
22. Mashup vs Portals
Portal Mashup
Content aggregation takes Content aggregation can
place on the server take place either on the
Location server or on the client
dependencies
"Salad bar" style: "Melting Pot" style –
Aggregated content is Individual content may
presented 'side-by-side' be combined in any
Aggregation without overlaps manner, resulting in
structured hybrid content
style
23. Mashup vs Portals
Portal Mashup
Read and update event models CRUD operations are
are defined through a specific based on REST
Event 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.
24. 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
25. 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
26. Types of Portals
• Personal portals
o a site on the Web that provides personalized
capabilities to its visitors, providing a pathway to
other content.
27. Types of Portals
• Business portals
o designed for
sharing and
collaboration in
workplaces
28. Types of Portals
• News portals
o new media channels
give them the
opportunity to reach
the viewers in a
shorter span of time
30. Types of Portals
• Cultural portals
o aggregate digitised cultural collections of galleries,
libraries, archives and museums. .
31. Types of Portals
• Corporate web portals
o Intranets. (similar to business portals)
32. 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
33. Types of Portals
• Search portals
o Search portals aggregate results from several search
engines into one page
34. Types of Portals
• Tender's portals
o a gateway to search/modify/submit/archive data on
tenders and professional processing of continuous
online tenders.
35. 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
36. Types of Portals
• Domain-specific portals
o specific to the particular domain, offering access to
related companies and services