1 multimedia services service provider service client service registry publish find/discovery bind...
TRANSCRIPT
1
Multimedia Services
Service provider
Service client
Service registry
Publish
Find/discovery
Bind
MultimediaServices
Framework and architecture
2
Course materials
• Framework and architecture– Jilles van Gurp, Anssi Karhinen, Jan Bosch: Mobile Service
Oriented Architectures (MOSOA)
– Jia Zhang, Jen-Yao Chung: An open framework supporting multimedia web services. Multimedia Tools Appl. 30(2): 149-164 (2006)
– Vassilios N. Koukoulidis, Mehul Shah: The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications. Multimedia Tools Appl. 28(1-2): 203-220 (2006)
3
Reading paper - hint
Introduction
Problem Statement
Architecture Drivers
Related work
Conclusions, future worksThree MSOA
5
Goals
• Number of devices– Wide variety of devices
• Native features– Software: text input
– Hardware: camera, screen
• Time to market• Window of opportunity
– Services are available as devices on the market
6
Architectural Drivers
• Usability– Find and use services
• Portability• Deployability
– Client side deployment, e.g., installation
• Scalability– Business
– System
12
IP Multimedia Subsystem (IMS)
Introduction
Network architecture• IMS• Standard org.
– Standard bodies
– Collaboration
• Protocols
IMS application development• Architecture• Native vs. Java appl.• Example
Operator benefits
14
IP Multimedia Subsystem (IMS)
CSCF
MRF
AS
MGCF
MGW
ApplicationLayer
Session ControlLayer
ConnectivityLayer
PSTN/PLMNIP Network
HSSSIP
H.248
DIAMETER
SIP
SIP
15
IMS SIP Protocols
• Session control protocols SIP– Establish, modify and terminate multimedia sessions
– Independent of the media being transported
– SIP is based on an HTTP request/respond transaction model
– Transport protocols TCP or UDP
• Main methods of SIP• Works in close conjunction with Session Description
Protocol (SDP)– Session level information
– Media level information
16
Session Establishment
• Session initiation– Discovery
• Delivery of session description– SDP
• Session management– Media stream
• Real Time Protocol (RTP)
• Real Time Streaming Protocol (RTSP)
• Session termination
Multimedia Data/System
17
IMS Protocols
• Media plane protocols– RTP
– RTSP
• Security and authentication protocols– DIAMETER
• Sh interface
19
SIP client/server architecture
• Call Session Control Function (CSCF)– Proxy-CSCF (P-CSCF) is the first point of contact for users
with the IMS• security of the messages between the network and the user and
allocating resources for the media flows
– Interrogating-CSCF (I-CSCF) is the first point of contact from peered networks
• querying the HSS to determine the S-CSCF for a user
– Serving-CSCF (S-CSCF) is the central brain • processing registrations to record the location of each user, user
authentication, and call processing
• operation of the S-CSCF is controlled by policy stored in the HSS
20
SIP client/server architecture (cont)
• Home Subscriber Server (HSS)– master user database that supports IMS network entities
that handle calls and sessions – contains user profiles, performs authentication and
authorization of the user, and can provide information about the physical location of user
• User Profile – contains information about the current user– the S-CSCF downloads it uses when a user is registering on
the network
• Sh application– interface allows an application server to communicate with
the HSS to extract the necessary data to dispatch the logic of the service
25
Movie Location Service Protocols
• Communication protocols between components• Messaging• Presence• Streaming video• Calendar• ….
Services
Servers
Clients
provides
uses
27
Movie Location Service
• Demonstrates a multimedia service• IP multimedia subsystem• Client-server architecture
• Originally designed for third-generation mobile phones• extended to handle access from WiFi networks and access-
independent platform for service delivery
Service provider
Service client
Service registry
Publish
Find/discovery
BindCompare with SOA???
28
Movie Location Services…
• Technology neutral– Invocation mechanisms (protocols, descriptions, discovery)
should comply with accepted standard
• Loosely coupled– Must not require knowledge at the service side
• Support location transparency– Service can be discovered and invoked by clients
irrespective of their locations
• Simple and composite services