Spatial Reuse Protocol: Spatial Reuse Protocol: A Ring Based A Ring Based LAN / MAN / WAN LAN / MAN / WAN MAC Protocol MAC Protocol

rockyboygangNetworking and Communications

Oct 24, 2013 (3 years and 10 months ago)

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Spatial Reuse Protocol:
Spatial Reuse Protocol:
A Ring Based
A Ring Based
LAN / MAN / WAN
LAN / MAN / WAN
MAC Protocol
MAC Protocol
Mike Takefman
Mike Takefman
1
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Goals
SRP Goals
• Improve economics via layer elimination
and BW multiplication
• Provide fast protection and restoration
• Enable Plug and Play operation

Support LAN, MAN and WAN applications
2
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Applications
SRP Applications
Si Si
Regional
Metro Access
Leased
Transport
Ring
Lines
Ring
Dedicated Access
Backbone
PoP Ring
Ring
HFC HFC HFC HFC
Cable Data
Regional
Server Access
Access Ring
Transport
Ring
Ring
HFC HFC
HFC HFC
3
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SONET/SDH-Based
SONET/SDH-Based
TDM Transport
TDM Transport
• Accepted transport
architecture
Provisioned
Provisioned
Connections Protection
Connections Protection
Performance monitoring

SONET
SONET
SONET
and self-healing
ADM ADM Working
Working
ADM
Expensive and

SONET/SDH
inefficient for packets
Ring
Multiple equipment layers
SONET SONET
SONET SONET
SONET SONET
ADM ADM
ADM ADM
ADM ADM
Bandwidth inefficiency
SONET SONET
SONET
ADM ADM
ADM
4
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. Transport Flexibility and
Transport Flexibility and
Evolution
Evolution
SONET
SONET
ADM
ADM
Dark Fiber
SONET
SONET
SONET
SONET
ADM
ADM
ADM ADM
SRP
SONET
SONET
Ring
ADM
ADM
WDM
~ ~
~ ~
~ ~
~ ~
~ ~
~ ~
•Runs over dark fiber, SONET, or WDM
•Enables transport “mix and match”
•Provides efficient evolution path for existing networks
•Provides optimized transport for greenfield builds
5
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. Previous Intra-POP
Previous Intra-POP
Connectivity Options
Connectivity Options
Internet Backbone Internet Backbone
Existing topologies

FDDI ring
Shared
FDDI Ring
X X
X X Switched FDDI
FDDI
Switch
ATM or Fast Ethernet
Point-to-point POS
Internet Backbone
Issues

Internet Backbone
622-Mbps
BW limits
POS
Complex load balance
622-Mbps
622 Mb/s ATM
POS
1 Gbps Ethernet
Multiple boxes
Port counts
155- or 622- Mbps ATM 155-Mbps POS
100-Mb Ethernet
6
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Overview
SRP Overview

Maximize BW efficiency
dual counter rotating rings
destination stripping
statistical muxing of BFP

Extend IP functionality
over MAN & WAN

Minimize provisioning
and configuration
7
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Overview
SRP Overview

Multicast support

2 Traffic priorities on ring
High priority traffic has low latency path
around ring
SRP fairness algorithm (SRP-fa) controls
access to ring BW for low priority traffic

8 priority levels for Tx and Rx queueing
8
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Cooperates with Layer 3 CoS
SRP Cooperates with Layer 3 CoS
to Extend Functionality
to Extend Functionality
Precedence Setting Rate Control
Laye Layer 3 r 3— —IP IP
Congestion Control Granular Scheduling
RED/WRED DRR on Eight Classes
Big Fat Pipes Low-Priority Fairness
Layer 2— Layer 2—
SRP SRP MAC MAC
High-Priority Bypass Precedence Mapping
• Layer 3 provides rich functionality and granular controls
MAC provides speed and simplicity

• Enables low delay/jitter for voice and video packets
9
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Overview
SRP Overview
• SRP fairness algorithm
(1) (1)
(2) (2)
Distributed algorithm
Propagates and uses
Node 1
Node 1
MAC usage info
Source and forward rate
(3) (3)
(4) (4)
(5) (5)
controls
Rapid adaptation
and convergence
Node 2
Node 2
10
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Overview
SRP Overview

Scalable: Bit-rate; Circumference of
ring; Up to 128 nodes

Intelligent Protection Switching (IPS)
Survivability in the event of single fiber /
node failure, or signal degradation
• Media independent protocol
Initial implementation uses SONET/SDH
framing
11
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. SRP Packet
SRP Packet
• SRP is a media independent MAC layer protocol
• The initial implementations utilizes Byte
Synchronous HDLC within SONET/SDH framing
(OC-12c, OC-48c, OC-192c)
• Allows transport via: Dark Fiber; SONET/SDH;
WDM
Tran Transport sport Path Path
Payload
Payload
Overhead Overhead
Overhead Overhead
F F
F F
F F
MAC MAC
L L
L L
Payload
Payload C C
A A A A
Header
Header
S
S
G G G G
12
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. Comparison with DQDB
Comparison with DQDB

No segmentation and reassembly
complete packets stored and forwarded

Distributed fairness without master nodes
• Protection switching without master
• High priority traffic for delay sensitive
applications
No support for isochronous traffic
13
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. Comparison with FDDI
Comparison with FDDI

Greater than 2x bandwidth improvement
both rings carry traffic
Destination stripping allows spatial reuse

No token to pass

FDDI-2 supported isochronous traffic &
master node
not generally implemented
14
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc. Summary
Summary
• Scalable packet ring technology
Bit-rate; Number of Nodes; Ring
Circumference

High bandwidth efficiency

Cost effectiveness

Distributed fault tolerance
• LAN, MAN and WAN applications
15
IEEE SRP Tutorial March 2000
© 2000, Cisco Systems, Inc.