Download Document

Presentation_ID
© 2001, Cisco Systems, Inc. All rights reserved.
1
Is Internet Ready for
Multimedia?
Petre DINI
Senior Technical Leader
Cisco Systems, Inc., USA
Concordia University, Montreal, Canada
[email protected]
MMNS 2002 Panel
MMNS 2002
© 2002, Cisco Systems, Inc. All rights reserved.
2
What must be ready?
Today
QoS, ToS
Multimedia
Text, Graphics
Voice
Video
Multimedia
traffic
End-points
Congest
ion
QoS
Internet
Sharing
Core
End-points
Tomorrow
QoS, Pricing
MMNS 2002
Santa Barbara, CA
User
User
Multicast
Unicast
Packetscheduling
User
User
IntServ
DifServ
PolicyMPLS
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
3
Multi-target Readiness
Technology
Deployment
-Many IP phones,
-Many VoIP ports
shipped
- Great strides in control
and signaling
- H.323, SIP,
MEGACO/MGCP
Operations
Business
-Traditional telephony
business models
- Music exchange
- Video-conferences
- Video-phones
MMNS 2002
Santa Barbara, CA
User-aware
- SLA, QoS, Costs
- Service interactions
- User perception
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
- IP PBX
- Class 4/5, PSTN
replacement
- Managed services
4
Why “almost ready”?
Text, Graphics
- E-business
- Portals
- www
- E-mail
--?
Voice
- SVMSs
- Legality
-?
Video
-SLA
-Billing
- Legality
-?
Multimedia
-Service guarantee
-Mixed SLAs
-Security/Privacy
-?
??????
- …………………..
- End-to-end congestion control
- Delay-tolerant multimedia networks
- Fairness use (credits/penalties, costs models)
- User QoS perception multimedia network aware
- ………………….
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
5
End-to-end congestion control
- Round-robin (high computational complexity, modification to routers)
- Slow start (collaboration of all end-users)
- Congestion avoidance (based on a modest performance required)
- Fair queuing paradigm for end-to-end congestion control (protocol design)
- TCP relies on collaboration of all the end-users (same common mechanisms)
- TCP-friendly paradigm as the basis
(the throughput for a flow must decrease when its loss increases)
1. - However, audio and video applications are loss-tolerant, and the degree
of loss-tolerance can be controlled with forward error correction
- this is supported without significant decrease in the quality perceived by
the end user; but these applications don’t tolerate frequent variations of
throughput
2. – TCP-friendly paradigm is not appropriate for multicast flows, since a
source-based congestion control scheme for multicast flow must adapt
its sending rate to the slowest receiver (in sense of throughput computed)
Given the size of Internet networks, TCP-friendly assumption is questionable
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
6
Delay-tolerant multimedia networks
Thinking Interplanetary Multimedia
- The Evolving Interplanetary Internet/Delay Tolerant Networks
- Multimedia Internet services across interplanetary distances
- Long/variable delays (propagation, queuing, clocking, processing):
- Interactivity is affected by delay
- Variability in delay may affect applications and protocols
- Privacy/Authorization for multimedia applications may be affected by
cryptographic processing on simple processors
- Reasonable estimation of retransmission time out value becomes complex in
networks where variable/unknowing queuing delays occur
- Special multimedia applications may be affected:
- Image transmission with frequent link interruptions
- Multimedia applications exhibiting long delays, significant data loss,
potential long link outages
Excessive latency affecting TCP directly by limiting its throughput performance
Data rate asymmetry affects TCP by altering the smooth flow of acknowledgments
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
7
User QoS perception
multimedia network_aware (i)
• Objective and subjective QoS parameters
• Relationship between user participation and user satisfaction
• Four contingency factors (task complexity, system complexity,
user influence, user-developer communication)
• Measuring user satisfaction
• Collect information within the scale excellent....poor, via
questionnaire
• User computer-assisted perception
• Comparative perceptions
• QoS user interface
• User friendly approaches
• Preferred/achieved QoS
• Self-adaptable/graceful degradation QoS
Internet Multimedia must be user-centric
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
8
User QoS perception
multimedia network_aware –ii• Satisfy user needs within a given cost
• Correct translation of QoS parameters from the user
specification to the desired ´´item´´ through the network
• Cover the cost for offering a given multimedia service
• Stimulate the service providers to improve their services
• Evaluate correctly the cost effort to create a new service
• Select various models to price the QoS degradation
• Establish the criteria to automatically adapt the QoS
with respect to the user constraints and the network
unexpected behavior
• Classify properly the user within the given profiles and
automatically manage the profile changes
If QoS pricing should vary with the network state, how quickly?
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
9
Fairness
(credits/penalties, costs models)
´´I think it´s ridiculous to have to pay extra for a fundamental
service´´ such as bandwidth.
Mike McQuary, President and CEO at MindSpring Enterprises Inc, Atlanta
´´How would such services be priced?´´
´´Consumers and business are also interested in
result-oriented pricing as well´´.
John Patrick, IBM Internet Technology Vice-President
( several scenarios with pricing schemes ranging from charging a fee on
an access-speed basis in some cases to including the fee in the cost of content
in others)
´´Whatever economic models materialize, they´re not likely
to include flat-fee pricing´´.
Clay Rider, Director at Zona Research, California
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
10
Expectations from Multimedia Internet
Protocols
• Cost-based scheduling
• Providing guaranteed performance or graceful degradation
• Allocating appropriate resources especially when users’
demand exceeds the network capacity
• Pricing mechanisms that change according to QoS parameters
• Considering ´´time´´ divided into pricing intervals
• Providing the following mechanisms:
• Rate control techniques for synchronization and bundling of multimedia
connections as well as for multimedia squeezing to control the discrete time
independent media used simultaneously with continuous time dependent media
• throughput scalability support based on dynamic rate control and threshold QoS
monitoring
• Adaptive acknowledgement and retransmission techniques considering QoS
requirements of specific media data and different network conditions
(ATM, satellite, etc.)
Result-oriented pricing
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
11
Profiling Multimedia Users and
Multimedia Applications
• An application programming interface must allow a user to
define its QoS profile
• A user profile includes:
• A MM profile which indicates the desired QoS parameter values
• A MM profile which indicates the worst acceptable QoS parameter values
Multi Media Profile
AudioProfile
VideoProfile
ImageProfile
TextProfile
audioQuality
CD, phone
language
F, E, R,...
colour
b&w, gray,..
resolution
HDTV, TV
frameRate
HDTV rate,..
colour
b&w, gray,..
resolution
HDTV res
TV res
minimal res
language
F, E, R,...
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
CostProfile
audioMaxCost
videoMaxCost
picturemaxCost
testMaxCost
documentMaxC
Petre DINI
TimeProfile
delay to receive a doc.
max. duration of a doc.
synchronization Q
good
acceptable
excellent
12
Multimedia QoS, where are we?
Multimedia QoS is as good or as bad, as the users perceive
it to be! (Jeffrey MacKie-Masson, Liam Murphy, John Murphy)
QoS
level
?
QoS as a key strategic driver
minimum level
time
AS MUCH QoS REGULATION AS NECESSARY,
AS LITTLE QoS REGULATION AS POSSIBLE
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
13
Discussions
MMNS 2002
Santa Barbara, CA
© 2002, Cisco Systems, Inc. All rights reserved.
Petre DINI
14
© 2002 , Cisco Systems, Inc. All rights reserved.
15