Sender

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IP Precedence network
High Precedence packet stream
Low Precedence packet stream
Sender
Receiver
Low precedence packets have a higher delay and
loss probability
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Sender
Receiver
A flow state of reserved resources is maintained
along the end-to-end network path by imposing a
local resource reservation state on every router
along the selected network path.
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Routing Agent
Reservation Setup Agent
Management Agent
Management and Control Functions
Admission Control
Traffic Control Database
Routing Database
Packet Scheduler
Output Driver
Input Driver
Classifier
Forwarder
Packet Scheduler
Data Path
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Sender
Receiver
Playback Buffer
Receiving Rate, showing Network-induced jitter
Sending Rate
Playback Rate
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Minimum Policed Unit m
Token Stream
Average Admission Rate r
T
T
T
Burst Volume b
Maximum Policed Unit M
Token Bucket
T
T
T
T
T
Peak Burst Rate p
T
T
T
Input Packet Queue
Rate Governed Output Packet Stream
Token Regulator
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Two level Queuing Discipline
Queued Packets
Fair Queuing Scheduler
Flow 1
Flow 2
Priority Scheduler
RSVP reserved Traffic Flows
OutputDriver
Flow 3
Traffic Classifier
FIFO Scheduler
Best Effort Traffic
Best Effort
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Application
RSVP Signaling
RSVP Process
RSVP Process
Resource Controller
Policy Control
Policy Control
Routing Process
Admission Control
Traffic Controller
Data Flow
Traffic Profile Enforcer
Traffic Classifier
Forwarder
Scheduler
ROUTER
HOST
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An RSVP PATH message is sent from the sender to
the receiver to set up a path state from the
sender to the receiver
IP HEADER RSVP HEADER PATH MESSAGE
Sender
Receiver
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The Receiver responds with an RSVP RESV message
which includes a resource profile of requested
resources. Each node sets up a reservation state
and then passes the message upstream.
IP HEADER RSVP HEADER RESV MESSAGE QoS PARAMETERS
Sender
Receiver
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Where two RESV message merge, the merge point
combines the two messages and forwards a single
RESV upstream.
IP HEADER RSVP HEADER RESV MESSAGE QoS PARAMETERS
Receiver A
Sender
Receiver B
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ATM
Internet
Boundary
ATM Signaling
RSVP Signalling
ATM Cells
IP packets
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IP data
IP data
RSVP Control
RSVP Control
802 Header Stripping
Address Mapping
Request Module
Request Module
IN SBM
OUT SBM
SBM Prop
802 Header
Admission Control
Admission Control
Bandwidth Allocator
Bandwidth Allocator
Filter
Scheduler
Packet Scheduler
Packet Scheduler
Traffic Class Mapper and Policier
Traffic Egress Class Mapper
Classifier
Classifier
RSVP-Controlled Sender with ISSL
RSVP-Controlled Receiver with ISSL
SBM 802 ISSL Switch
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RSVP mapped over IP
RSVP mapped over SBM
RSVP mapped over SBM
Sender
Integrated Services Domain
SBM Domain
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Simulation of multiple TCP sessions and real-time
UDP data flows
L o a d
TCP Flows
Real-Time UDP flows
Expansion of a sample interval
Time
L o a d
TCP Flows
Real-Time UDP flows
RTT interval
Idle Interval
Time
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Admission System
Data stream classified into a set of behavior
aggregates
Input Data stream
Admission Systems deployed at the edge of the
Differentiated Services Network
Interior systems apply Per Hop Behaviors to
packets based on the service code set by the
admission systems.
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IP Header
Version
IHL
Total Length
DS Field
Flags
Identification
Fragment Offset
Time To Live
Protocol
Header Checksum
Source Address
Destination Address
Options
Padding
Currently Unused
Differentiated Services Code Point Value
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Accounting of traffic within the Service
Aggregate with a rate meter to measure the
traffic profile
Service DSCP written to IP Header
Profile Enforcer for the Service Aggregate
Meter
Marker
Shaper / Dropper
Meter
Packets entering the network
Marked Packets passed to the Forwarder
Marker
Shaper / Dropper
Classifier
Meter
Marker
Shaper / Dropper
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Routing Agent
DiffServ Policy Manager
Management and Control Functions
Admission Control
Marker Control
Routing Database
Meter Profiler
Marker / Dropper
Packet Scheduler
Output Driver
DSCP Classifier
Input Driver
Classifier
Forwarder
Packet Scheduler
Data Path
Per-Packet Scheduling Action determined by the
packets DiffServ Code Point
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Routing Agent
Management and Control Functions
Routing Database
Packet Scheduler
Output Driver
DSCP Classifier
Input Driver
Forwarder
Packet Scheduler
Data Path
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Routing Agent
DiffServ Policy Manager
Management and Control Functions
Routing Database
Marker Control
Data Path
Packet Scheduler
Egress Marker
Output Driver
DSCP Classifier
Input Driver
Forwarder
Packet Scheduler
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For lower weighted AF traffic the RED function is
triggered at lower average queue sizes, while
heavier weighted traffic uses a higher average
queue length to trigger random packet discard.
1
Gold AF Service discard probability
Silver AF Service discard probability
Bronze AF Service discard probability
Probability of Discard
Queue max.
0
Average Queue Depth
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1 - Sending Application negotiates service
profile with DiffServ Admission System
2 - Admission System makes admission decision
based on current network state and admission
policies
3 - Egress System negotiates service profile
along the path to the receiving application
Sender
Receiver
DiffServ Admission Point
DiffServ Egress Point
DiffServ Network
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DiffServ Egress System
DiffServ Admission System
DiffServ Transit network
IntServ Edge network
IntServ Edge network
Sender
Receiver
RSVP Path Reservation
RSVP Path Reservation
DiffServ Behavior Aggregate
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Topology and Policy Database
Policy Decision Point
COPS Protocol
Authentication Server
Policy Enforcement Point
Accounting Server
Admission Control System
RSVP Processor
RSVP Reservation
RSVP Reservation