Download Switch Router Design & Implementation

ITRI
CCL
Switch Router Design &
Implementation
Paul C. Huang, Ph.D.
ITRI / CCL / N300
[email protected]
CCL/N300; Paul Huang
2017/5/25
1
ITRI
CCL

Teaching Staff
Lecturer
» 黃肇嘉 ([email protected])

– MIT
Generalized Oversampled A/D Converter
EECS
BS / MS ‘87
– U. Tokyo
Multicast Routing Algorithms
EECS
Ph.D. ‘94
– Bellcore
Optical Switch / Optical Transceiver / High Speed Mux
– CCL
LAN switching
Teaching Assistant
» 魏煥雲 ([email protected])
» 張政賢 ([email protected])

CCL/N300; Paul Huang
Guest Lecturer
» 王耀宗
Switch-Router Testing Methodology
» 呂國正
Verilog Implementation of Routing function
2017/5/25
2
ITRI
CCL
Course Grading


Assignment Load
» 25%
3 sets of Homework assignments
» 30%
2 sets of Labs
» 15%
Presentation
» 30%
Final Project
Grading Policy
» Quality, not quantity
» Innovativeness
» Late penalty (15% daily, including weekends & holidays).
CCL/N300; Paul Huang
2017/5/25
3
ITRI
CCL
Course Schedule

(2/24)
Course Introduction
 General communications network basics
 Network market reality (success / failures)
 Evolution towards Switch Router: Why, Where, When, and How

(3/3)
The Basic Requirements of Switch Router
 IEEE / IETF overview
 Current System and IC product features & specification
 Current IC product architecture

(3/10)
Switch-Router Architectures
 Switch architecture
 IEEE 802.3 (10/100/1000 Mbps MAC)
 IEEE 802.3x

(3/17)
Switch-Router Testing Methodology (王耀宗)
 Lab I:
CCL/N300; Paul Huang
L2 Performance / Functionality Testing
2017/5/25
4
ITRI
CCL
Course Schedule

(3/24)
Traffic Management & Implementation Issues and Pitfalls
» Understanding Traffic Management
(RSVP, DiffServ, QoS, Buffering, Routing, Scheduling)
» Buffer Mgt

(3/31)
Traffic Management & Implementation Issues and Pitfalls
» Queue Mgt.
» Scheduler

(4/7)
Routing Implementation Issues and Pitfalls
» Route Forwarding Techniques
» Implementation Issues at Gbps
» Example Implementation

(4/14)
Verilog Implementation of Routing function (呂國正)
» Lab II:
CCL/N300; Paul Huang
L3 Performance / Functionality Testing
2017/5/25
5
ITRI
CCL
Course Schedule

(4/21)
Routing Algorithms
 Basics of Routing
 Classification of Current Routing Algorithms & Protocols
(Unicast / Multicast)

(4/28)
Implementing Unicast Routing Functions
 Interior Routing Algorithms (RIP)
 Interior Routing Algorithms (OSPF)
 Exterior Routing Algorithms (BGP)

(5/5)
Implementing Multicast Routing Functions
 (Multicast Routing (DVMRP)
 Multicast Routing (PIM)
 Multicast Routing (CBT)

(5/12)
Advance Routing Topics
 ATM Routing Protocol (NHRP)
 Policy-based / CoS / QoS Route
 Final Project:
CCL/N300; Paul Huang
2017/5/25
6
ITRI
CCL
Course Schedule

(5/19)
Project presentation
 (50 min / group): Total 3 groups.

(5/26)
Project presentation
 (50 min / group): Total 3 groups.
CCL/N300; Paul Huang
2017/5/25
7
ITRI
CCL

Course Benefits
Industry focus

» Market reality
» English comprehension
» Standards process
» Interactive (hopefully)
» Product concepts

Additional benefits

Knowledge focus
Unfocused on …
» Not presentation of protocols
» Networking fundamentals
» Not theoretical
» Testing fundamentals
» Not number crunching
» Actual design trade-offs
» Design concepts
Thanks for being my guinea pigs
CCL/N300; Paul Huang
2017/5/25
8
ITRI
CCL
Teaching Philosophy
Confucius (Eastern)
Socrates (Western)
Knowledge
CCL/N300; Paul Huang
Knowledge
2017/5/25
9
ITRI
CCL
Network Engineering
Why are you interested ?
How is it different ?
Is it your cup of tea?
CCL/N300; Paul Huang
2017/5/25
10
ITRI
CCL
IT
• PC Motherboard
• PC Manufacturer
• Notebook
Taiwan’s Industry
PC Peripheral
DataComm
•
•
•
•
•
•
•
•
•
Modem / NIC
Add-on Cards (Graphics)
Scanner / Digital Camera
Monitor / LCD Monitor
CPE
•
•
•
•
•
IC Design House
Foundry
CCL/N300; Paul Huang
Systems Integration
• Switch-Router
• DSLAM
• Access Switch
TeleComm
• Telephone
• KTS
•
•
•
•
10/100/1000 NIC
Dual Speed Hub
L2 Switch
SOHO Router
Wireless LAN
xDSL Modem
Cable Modem
Cellular Phone
DLC / HDSL
RAS
Software
•
•
•
•
Internet Middleware
OS
Protocol
Applications
PC Chipset
Network Chipset
Consumer IC
Memory
LCD
Opto-Electronics
2017/5/25
11
ITRI
CCL


Key Engineering Skills
Telecommunications

» Scalability
» Accuracy
» Reliability
» Speed
» Completeness
Data communications

» Compatibility
» Standards conformance

Manufacturing Equipment
» Flexibility
» Reproducibility
Information Technology

» Manufacturing Cost
» Logistics

Test Equipment
Mobile
» Miniaturization
» Low power
Foundry

» Manufacturing Cost
» Yield Process
Wireless
» SNR
» Error recovery
CCL/N300; Paul Huang
2017/5/25
12
ITRI
CCL
Fundamental Engineering Skills

Theoretical
» Mathematics / Physic
» Algorithmic
» Modeling

Design
» Power
» Analog Circuit
» Digital Logic
» Software
» Architectural

CCL/N300; Paul Huang
Protocol
2017/5/25
13
ITRI
CCL
Key Engineering Value

Intellectual Property
» Patents, copyright, trade secrets

Service Differentiation
» Functional
» Management

Content
» Information
» Knowledge
CCL/N300; Paul Huang
2017/5/25
14
ITRI
CCL
The Value Chain in Networking has Changed
Chips
Software
Chips
System Design & Integration
Software
System
Manufacturing
Manufacturing
Distribution
Distribution
Already Happened in the PC Business
• Intel makes the chips; Microsoft makes the software.
• Dell and Compaq focus on manufacturing, relentless cost cutting,
and distribution, not R&D
• Little system-level innovation, few new system startups
• Plenty of silicon innovation; plenty of silicon startups
• Shift from managing scarcity to creating abundance
CCL/N300; Paul Huang
2017/5/25
15
ITRI
CCL
Porter’s Industry Attractiveness Model
Threat of Competitor
Customer Power
Industry Attractiveness
Supplier Power
Threat of New Entrant
CCL/N300; Paul Huang
2017/5/25
16
ITRI
CCL
國內 Networking IC 現況

網路 IC 戰雲密佈, MB/NIC 卡爭鋒, 瑞昱. 旺宏. 聯傑. 威盛. 上元. 民生. 大
智. 矽統及華邦等開始 10/100 Mbps 單晶片量產供貨

雙速集線器 IC 定位成功, 宏三乘勝推出 8 埠新產品, 耘碩. 聯傑. 上元. 凱
訊. 亞信. 旺宏. 瑞昱等網路 IC 設計公司打算推出三合一集線器晶片

亞信於台北電腦展展出八埠 N-Way Switch 的嵌入式 DRAM 網路晶片,
此顆 IC 內含 32 位元 RISC 及 2MB SDRAM

瑞昱量產網路交換器 IC, 首批國產四埠交換器 IC 月產能已超過一千顆
(87/12)

上元科技推出台灣第一顆八埠交換器整合單晶片 (87/12)

聯傑購併美商 NETio 獲得先進交換器晶片技術, 目前正研發二埠和八埠
高速以太交換器晶片 (88/1)
10/100M NIC Single Chip
1998
N-Way Switch Single Chip 8/16 ports
1999
2000
Dual-speed Hub Single Chip 8/12 ports
CCL/N300; Paul Huang
2017/5/25
Layer 3 Switch 8/16 ports
17
ITRI
CCL
Product Line of Ethernet LAN IC
IP
MAC
PHY
NIC
NIC
3 in 1
PHY
Single
PHY
2 in 1
Single
Speed
Hub
3 in 1
Dual
Speed
Hub
3 in 1
Octal
Port
Switch
8 +1
Layer 3
Switch
Quad Port
Gigabit
Layer 3
Switch
8 +1
Layer 2
Switch
Quad Port
Gigabit
Switch
Quad
PHY
TXVR
Transceiver
10Mbps
CCL/N300; Paul Huang
Dual
Port
Switch
Hub
Contr..
Octal Port
Layer 3
Switch
100Mbps
2017/5/25
1000Mbps
18
ITRI
CCL
Network Technology
Creating abundance
Velocity of change
CCL/N300; Paul Huang
2017/5/25
19
ITRI
CCL
Technology Pace has Exploded
Technology Applications
Transistor
IC /Processing
CPU
DSP Chips/ Lithography Technology
IC Design
(Spice Modeling)
2DAnalog
/ 3D Graphics
Engine
Memory (Rambus)
LCD Displays
A/D Conversion
10 Computing
/ 100 / 1000Technology
Ethernet
DSP
Algorithm
Multi-Layer Ethernet Switch
Digitization
xDSL
(G.Lite, ADSL, VDSL, etc.)
Software
Technology
Cable Modem
Technology
Technology
Technology
Creation
Creation
Explosion
Terabit Switch-Routers
Dense
WDM Technology
Networking
Packet / Cell Switching
FocusFiber
on Technology
Innovation,
Optical
/ Laser Technology
NotScience
Technology Invention
Material
CCL/N300; Paul Huang
2017/5/25
20
ITRI
CCL

Technology Creating Abundance
Chips for networking have twice as many gates every 18
months, thanks to Moore’s Law.
» We can build network systems on a chip for minimal incremental cost or
“free”.
» We can pack billions of DSP ops/sec on a chip. We
» We can route 10s of millions of packets/sec on a chip.

Optics performance doubles every 12 months. Twice as many
wavelengths on the same fiber every year. Eventually, that
changes everything.

Packet switching (IP) is taking over everywhere. Fundamental
packet technology performance is doubling every 12 months,
outpacing alternatives. outpacing alternatives.
CCL/N300; Paul Huang
2017/5/25
21
ITRI
CCL
Moore’s Law Meets Network ICs
 Cost is dropping to $15/port
 Full L3 and L4 routing, QoS, accounting, etc. “for free”
 New standards like DiffServ, RSVP, H.323, IPsec, can all
be handled with the same chips at the same cost
$45
 Total Bill of Materials for 10K boxes/month
$40
$35
$30
$25
$20
$15
$10
End’97
Mid’98
End’98
L2 through L7
Mid’99
Managed L2
Source : MMC networks
CCL/N300; Paul Huang
2017/5/25
22
ITRI
CCL
DWDM: A Breakthrough Technology
350
OC-192, 32l
2000: OC-192, 80 l
300
2001: OC-192, 160 l
2002: OC-192, 320 l
250
OC-48, 96l
200
OC-192, 16l
150
OC-48, 48l
100
50
OC-192, 4l
CCL/N300; Paul Huang
2017/5/25
1999
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
0
1998
OC-192, 2l
1997
System Capacity (Gbps)
Doubling Each Year:
23
ITRI
CCL
Demand Growing Faster than Technology
Basic technology
Performance doubling time
Moore’s Law -gates/chip
18 months; 59% / yr.
Optical fiber - bps/fiber
12 months; 100% / yr.
Packet switching - $/bps
12 months; 100% / yr.
Basic demand
Traffic doubling time
Internet users
12 months; 100% / yr.
Data bits
7.5 months; 300% / yr.
Internet core
4 months; 1,000% / yr.
CCL/N300; Paul Huang
2017/5/25
24
Changing of the Era: SONET  WDM
ITRI
CCL
The SONET Era
The WDM Era

“Free” local calls, expensive
long distance

Expensive access to “free”
backbone

Circuit/TDM model

Packet model

Transmission was king;
efficiency was key.

Switching is king;
features are key

Service was based on
multiplexing

Service is based on
internetworking

Data used existing transmission

Data demands new transmission

Few, legacy carriers
with legacy nets

Thousands of new carriers
with new nets

Managing scarcity

Creating abundance
CCL/N300; Paul Huang
2017/5/25
25
ITRI
CCL
Changing of the Era: Network Processor
Original Assumptions
New Assumptions

IP routing is based on destination
address

Can route on SA, DA, port, URL, DS
types, etc.

Routers can maintain only a few
queues per port

Routers can have tens of thousands of
queues

Fast switching must be very simple

Chips can be application-aware, still
run at many Gbps

Signaling, traffic management should
be done only at call setup

Its possible to do shaping, policing,
WFQ, NAT, tunneling for each packet

Very fast switching requires fixed
length cells

It is no harder to switch a packet than
a cell

Cell and frame networks are very
different

In hardware, cells and frames are
interchangeable.
CCL/N300; Paul Huang
2017/5/25
26
ITRI
CCL
Changing of the Era: Packetization
This transition is as fundamental as the shift from analog to digital
CCL/N300; Paul Huang
Before Packet
After Packet
Backbone trunks:
TDM/SONET
IP/WDM
Backbone switches:
4ESS, ADMs
IP gigarouters
Local voice switches:
5ESS
IP access routers
Local data switches
5ESS
DSLAMs
Metro rings:
TDM/SONET
IP/WDM
Business access:
TDM/T1
IP/DSL
Residential access:
Dial
IP/cable modems
Enterprise data nets:
SNA
VPNs/IP
Broadcast, cable TV:
Analog FDM
MPEG packets
Storage networks:
SCSI
IP/Fibre Channel, GE
Consumer electronics:
Proprietary
FireWire
2017/5/25
27
ITRI
CCL
Changing of the Era: Service Networks
Telco Business Model
Internet Business Model

Regulated monopolies

Unregulated providers

Protected local / domestic markets

Global market with global
competitors

High barriers to entry

Low barriers to entry

Pricing based on usage

Pricing based on access

Smart network

Stupid network

Stupid end devices

Smart end devices

Profits generated by managing
scarcity

Profits generated by creating
plenty
CCL/N300; Paul Huang
2017/5/25
28
ITRI
CCL
Network Service
Paradigm Shift
New business model
CCL/N300; Paul Huang
2017/5/25
29
ITRI
CCL
Biggest Driving Factor: Internet Traffic
Growth assumes more real-time services including multicast
Users
(Millions)
Usage Sizes
(KB)
Annual Packet Traffic
(Billion Packets)
5000
200
100-500,000
35
5
1990
1
1995
*
**
**
2000e
E-Mail
50
25
Web
Web,Video
Home-Page Infomercial
Surfing**
Usage***
1990
1000
1995
2000e
Presumes growth in PC-installed base from 1995’s 60 million to 2000’s 475 million
5KB/page x 10 Web pages per user
500KB/seconds x 10 seconds
Source: IDC, Zona Research, Literature Searches, Team Analysis
CCL/N300; Paul Huang
2017/5/25
30
ITRI
CCL
CCL/N300; Paul Huang
Internet’s Exponential Growth & Changes
2017/5/25
31
ITRI
CCL
The Current PSTN Model
Potential Competitors
Baby Bells, GTE
Connectionless
Signaling Network
SS7
4ESS, 5ESS
Thin Clients
Thin Clients
CCL/N300; Paul Huang
Connection-Oriented
Bearer Network
2017/5/25
32
ITRI
CCL
The Current Internet Model
Potential Competitors
1000’s ISPs, Telcos, HiNet
IP Routers
Thick Client
Thick Client
SONET, ATM
CCL/N300; Paul Huang
Connectionless
Bearer Network
2017/5/25
Connection-Oriented
Transport Network
33
ITRI
CCL
A Possible Future Model
Potential Competitors
AT&T (@Home), WorldCom (UUNet), AOL, DirectPC
Internet
Connectionless
Signaling Network
Thick Client
SS7-Aware
Gateway
Future Nets
Connection-Oriented
Bearer Network
• Application Specific
• VPN Capable
Thin Clients
CCL/N300; Paul Huang
2017/5/25
34
ITRI
CCL
Another Possible Future Model
Potential Competitors
Qwest, Level 3, Delta Three, Concentric, IDT,
Bigger Faster Internet
Thick Client
SS7-Aware
Gateway
Connectionless Signaling Network
& Best-effort Data Delivery
Connection-Oriented Services:
• IP Telephony
• VPN Capability
• Assured Data Delivery
Thin Clients
CCL/N300; Paul Huang
2017/5/25
35
ITRI
CCL
Network Architecture
Conventional Voice
(PBXs & phones)
Enterprise Protocol
IP / IPX / SNA
Enterprise Transport
Ethernet
ATM / FDDI / TR
Analog
IP / ATM
Frame Relay
Access: Protocol
Users want choice
and interoperability
Access: Physical
Applications
InternetAccess
provides
provide
the
Network
Network
Intelligence
EdgeServices
Cable
xDSL / ISDN
SONET / SDH
Satellite / Wireless
Core
TeleComm / Cable / Wireless provides the Access and the Transport
CCL/N300; Paul Huang
2017/5/25
36
ITRI
CCL
Network Convergence
Video
Voice
Core
Core
SNA
TDM
RAS
Wireless
Voice
Data
Service Specific
Vertical Integration
from
Access to Core
ISDN
EDGE
• Deregulation
• Technology
• The Internet
• Global Commerce
Voice
Voice
Core
Core
Data
FTTx
Frame
Relay
Core
EDGE
IP
ATM
Copper
VPN
Video
Intranet
Data
Data
Any access technology on a Common Edge/Core
Architecture offers great flexibility while reducing cost
CCL/N300; Paul Huang
2017/5/25
37
ITRI
CCL
Service & Content Revenue Trends
Private
Services
Public
Services
Content
Functional
Differentiation
Quality and
Cost
Managed
Intranets
Electronic
Commerce
VPN
Services
Internet
Services
Increasing
Value
Frame Relay, Cell Relay
Leased Line Services
7%
3%
10%
10%
1997 20%
25%
25%
30%
45%
2000
25%
Relative income from basic services decreasing
- value added services key to profitability
CCL/N300; Paul Huang
2017/5/25
38
ITRI
CCL
The new business driver . . . THE CUSTOMER
IP/ATM
Services
Regulated
Environment
Standards Bodies
Manufacturers
Service providers
ISDN
Customers
New Competitive
World
The market, not regulators
decide on standards today
CCL/N300; Paul Huang
2017/5/25
39
ITRI
CCL
Market Success / Failures
Why do some succeed & some fail ?
CCL/N300; Paul Huang
2017/5/25
40
ITRI
CCL
Networking : A Technology Timeline
Novell demonstrates
first networked
PC LAN
Robert Metcalfe
found 3Com
1969 1973
1979 1981
1982
Robert Metcalfe
and David Boggs
build first Ethernet;
2.944Mbps over coax
3Com ships
first 10Mbps
Ethernet adapter;
$950
CCL/N300; Paul Huang
IBM introduces
16Mbps token ring
adapter
IBM announces
4 Mbps token ring
$830 per node
Arpanet opens;
50 kbps, 4 hosts
1983
Fore and NET/Adaptive,
among others, announce
first ATM switches;
roughly $5000 per port
1985
IETF
established
1986
1987
1988
Cisco ships
AGS router
1989
Frame Relay
Forum founded
ATM Forum
established
1990
1991
1992
Sun
introduces
Iava
Bay Networks
established
1993
1994
Synoptic ships
first Ethernet hub
2017/5/25
1996
Ipsilon Networks
ships IP switching
Kalpana ships
first Ethernet switch;
$1450 per port
IEEE approves
802.3 Ethernet
1995
IEEE splits work
on fast Ethernet
into two groups,
100Base-T and 100VG
Alteon demos first
gigabit Ethernet switch
and adapter
41
ITRI
CCL
Market Tradeoffs
Cost
Functionality
Time to Market
Winner == Right Product at the Right Time at the Right Cost
CCL/N300; Paul Huang
2017/5/25
42
ITRI
CCL
Strategies and Corresponding Value Propositions
Market Segment
Vendor-Created
Market-Created
1
Innovative
Product
Replicative
CCL/N300; Paul Huang
3
Evolution
Breakthrough
2
4
Differentiation
Reposition
2017/5/25
43
ITRI
CCL
Broadband Network Market
Application
CPE
DataComm provides Network Intelligence
Department
Division
SBU
Corporate
Enterprise Networking
Internet Backbone
SOHO Networking
RAS (Copper,
Cable)
CO / Cable
SONET / DWDM
TeleComm / Cable / Wireless provides the Access and the Transport
CCL/N300; Paul Huang
2017/5/25
44
ITRI
CCL
LAN vs. WAN
LAN
WAN
Market size: US$ 12 billion
Market size: US$ 56 billion
Spending power is diffused: among 250,000
buyers
Spending power is highly concentrated: fewer
than 50,000 buyers account for more than
85% of all the money spent
Support cost dominates: 65% of the total cost Cost of bandwidth dominates: 75% of the
goes for support & management
total cost is consumed by recurring cost for
carrier services
Bandwidth is cheap: less need to conserve,
thus allowing multimedia, video
conferencing, or desktop collaboration.
Bandwidth is a scarce resource: needs to be
carefully controlled, conserved, and shared
via signaling, traffic mgt., and QoS
Latency: not a issue in high-speed shortdistance network.
Latency: important for real-time traffic such
as voice.
Connectionless: Packet switch
Connection-oriented: Circuit switch
CCL/N300; Paul Huang
2017/5/25
45
ITRI
CCL
Bridge vs Router
Need more Functionality
(VLAN, Multicast, Routing, etc.)
Available Approaches
Ethernet
Switch
Bridge
Router
• Big Fast Router
• Layer 3 Switch Router
• IP Forwarding Switch
• MPLS / IP Switch
• ATM Switch
Need for Lower Cost,
Higher Bandwidth
• ???
“ASICs are the technology enabler. Like the introduction of the microprocessor, new chips will
revolutionize the networking industry.”
-- David House (Chairman, President, and CEO of Bay Networks)
CCL/N300; Paul Huang
2017/5/25
46
ITRI
CCL
LAN Standards
IEEE 802.2
LLC
MAC
802.3
802.4
802.5
802.6
802.11
802.12
802.14
ANSI
Token
Passing
Ring
Dual Bus
Distributed
Queue
Wireless
CSMA
/CD
Token
Passing
Bus
Demand
Priority
Cable
TV
FDDI
I & II
Data
Link
Layer
PHY
LAN
CCL/N300; Paul Huang
LAN
LAN
Public
LAN
LAN
2017/5/25
LAN
WAN
Campus
47
ITRI
CCL
10 / 100
Ethernet Access
High Speed Networking
IP
IP
Ethernet
Ethernet
Frame Switch
Frame Switch
Gigabit
Ethernet Backbone
IP
IP Edge
Hub
Ethernet
Frame
Cell
IP
IFMP, GSMP, TDP
Cell Switch
IP Switch
Backbone
IP
ATM Edge
Hub
CIF Edge
Hub
ATM Edge
Switch
CCL/N300; Paul Huang
Ethernet
ATM
Frame
Cell
IPOA, LANE, MPOA
ATM
Frame
ATM
Cell Switch
ATM
Cell
Cell Switch
ATM
ATM
Cell Switch
Cell Switch
2017/5/25
ATM Switch
Backbone
ATM Switch
Backbone
ATM Switch
Backbone
48
ITRI
CCL
CCL/N300; Paul Huang
IP Switching Model
Integrated
Routing
3. Multi-Layer Switching
Model
(Tag Switching, MPLS)
2. Integrated Model
(IP Switching)
Layered
Routing
1. Overlay Model
(MPOA)
Simplified addressing,
Separate routing (NA)
Subnet Addressing
Peer Addressing
2017/5/25
49
ITRI
CCL
A Taxonomy of IP Switching Solutions
IP Switching
Peer
Overlay
Layer 3 Switch
Flow
Topology
Flow
Address Resolution
Layer 4 Switch
IFMP/GSMP
Tag Switching
MPOA
Classical IP
Gigabit Routers
CSR/FANP
ARIS
LANE
Terabit Routers
IP Navigator
NHRP
QoS Router
VNS
MARS
MPLS
RFC 1483 PVC
 Different environments warrant different solutions
 Factors : scalability, cost, simplicity, extensibility, etc.
CCL/N300; Paul Huang
2017/5/25
50
ITRI
CCL
Club Sandwich Debate (Protocols)
Demand for Internet
applications, plus new packet
technologies
VCs for flows, VPNs, Traffic
engineering.
IP
Very
Uneasy
Match
ATM
Provides
reliability,
provisioning
SONET
WDM
Very
Simple
Match
Provides cost breakthroughs
in bandwidth.
CCL/N300; Paul Huang
2017/5/25
51
ITRI
CCL

Other Success & Failure
Physical Interface

» Modems / ISDN / xDSL / Cable Modem
» OSI vs TCP/IP
» ATM
» ATM Forum vs IETF
– 25.6 Mbps, TAXI, SONET/SDH


Network Architecture
Other famous battles
» Wintel vs. Macintosh
» DLC
» VHS vs Beta
» HFC

» FTTC / FTTH

Protocol
Battles to come
» Terabit Cell vs Terabit Packet switch
WAN Protocol
» Frame Relay
» SMDS
» ATM

Network Management
» SNMP vs CMIP
CCL/N300; Paul Huang
2017/5/25
52
ITRI
CCL
Key to Success

An innovation is adopted more quickly if:
» Big Payoff: It shows an easily measured advantage relative to
existing methods, through low cost or great results.
» Investment Protection: It can be adopted compatibly, without
having to discontinue or discard the old approach. Often by
eliminating architectural changes and protocol development
–
–
–
–
Simpler interoperability — plug & play
Easier adoption — mix & match
Faster time to market — no waiting for standards
Greatly reduced complexity
» Low Risk: It lends itself to initial small-scale implementations
CCL/N300; Paul Huang
2017/5/25
53
ITRI
CCL
Fast Ethernet is a Winner
100 Mbps Ethernet
1. Big Payoff ?
Yes -- 10 fold speed-up for little or no cost
2. Investment Protection ?
Good -- and 10/100 chips enable a mix and
match installation
3. Low Risk ?
Yes -- very low cost, can be adopted
incrementally, can be sensed automatically
CCL/N300; Paul Huang
2017/5/25
54
ITRI
CCL
Frame Relay is a Winner
Frame Relay
1. Big Payoff ?
Yes -- Good price / performance vs. private lines
2. Investment Protection ?
Excellent -- just a software upgrade to most
boxes
3. Low Risk ?
Yes -- very low cost, can be adopted
incrementally, can grow to large size / high
speed
CCL/N300; Paul Huang
2017/5/25
55
ITRI
CCL
Multi-Layer Switch will be a Winner
Multi-Layer Switch
1. Big Payoff ?
Yes -- 10X performance for 1/10th the cost
2. Investment Protection ?
Excellent -- works just like a router, only faster
3. Low Risk ?
Yes -- very low cost, can be adopted
incrementally, can grow to large size / high
speed
CCL/N300; Paul Huang
2017/5/25
56
ITRI
CCL
Network Backgrounder
Introduction to various network devices
IP Switching
Tag Switching
CCL/N300; Paul Huang
2017/5/25
57
ITRI
CCL
Today’s Dominant Network Model
B
B
B
B

R
Routers (Pros)
R

» Broadcast Firewalls
» Dynamic Path
» Security

CCL/N300; Paul Huang
Bridges / Switches (Pros)
» Plug & Play connectivity
» Simplicity
» Performance
Routers (Cons)
»
»
»
»
»
H
H
R

Protocol dependence
Application fairness
Performance
Administrative Complexity
Scalability
Bridges / Switches (Cons)
»
»
»
»
2017/5/25
Broadcast storms
Bandwidth intensive for WAN
Static Path
Scalability
58
ITRI
CCL
Evolving Networking Architecture

Bridged network
» Microsegmentation

Collapsed backbone routers
» Use a router to tie shared-media or switched LAN segments together

Switched network
» Hierarchical network

VLANs with “one-armed” routers
» Used to contain broadcast to within one VLAN.
» Just like subnets, VLANs are interconnected by routers, except that
routers link virtual LANs, not physical LAN segments, leading to
the “one-armed” configuration of the router hanging off a switch.
» Focused on “switch when you can, route when you must” strategy.
CCL/N300; Paul Huang
2017/5/25
59
ITRI
CCL
Evolving Network Architecture

Cut-through routing
» Use route servers + “cut-thru” techniques to avoid the need to detour
all intersubet traffic through “one-armed” router bottlenecks,
thereby improving network efficiency and performance.
» Focused on “route once, switch many” strategy.

Gigabit Wirespeed Routing in Hardware
» Use the latest ASIC technology to perform routing in specialized
hardware.
» Focused on “route whenever you need to” without any performance
penalties or the need to create multiple VLAN network overlays.
CCL/N300; Paul Huang
2017/5/25
60
ITRI
CCL
“Best Effort”
“Guaranteed”
Next Generation Network
Datagram

Base Technology
Integrated

» Switch-Router

Protocol
Routing Hops

Pros



Protocol
» ATM + rest
Routing Hops

Pros

Pros
» Guaranteed QoS
» Virtual networking
» Multi-service
Cons
» Non-standard
Routing Hops
» 0 or 1
» Looks like a router &
performs like a switch
Cons
» Scalability

» ~ 2+
» It’s a router

Protocol
Base Technology
» ATM Switch
» IP
» Many


» ATM Switch
» IP / IPX

Base Technology
Overlay

Cons
» Complexity
» Forklift upgrade
CCL/N300; Paul Huang
2017/5/25
61
ITRI
CCL

The “Datagram” Model
“Router-based” Networks
» Routers are always in the datapath running common routing protocols
» All services (Routing, IP Multicast, CoS, etc.) are performed by routers.
» Latency = n( # hops, services, … ) = independent forwarding decision for each packet

Future Enhancements
» IP forwarding switch, Layer 3 switches, Layer 4 switches, Multi-layer switches
» Gigabit Switch Routers, Terabit Switch Routers (Tiny Tera)
Performance is optimized within a device; best-effort delivery
CCL/N300; Paul Huang
2017/5/25
62
ITRI
CCL
Historical Issues with Datagram

IP only
» Doesn’t support multi-service (ATM, Frame Relay)

Only “Best Efforts”
» Shared QoS = no QoS
» Router-based RSVP not scalable
» Too much latency for real time data delivery

Traditionally, router bandwidth is limited

Doesn’t support traffic engineering
But: Many of these issues are being corrected
CCL/N300; Paul Huang
2017/5/25
63
ITRI
CCL
The “Overlay” Model
S
E
S
S
S

S
S
One-arm Router
“Overlay-Model” Networks
» End-to-end / Edge-to-edge switching model
» Routing is performed only on connection setup
» Centralized control via some kind of server
– either to translate addresses or to provide routes
– limits the cost and complexity of edge devices
– IETF Standards:
– ATM Forum:
NHRP, MARS
LANE, MPOA
Performance is optimized end-to-end; Guaranteed QoS delivery
CCL/N300; Paul Huang
2017/5/25
64
ITRI
CCL

The “Overlay” Model — Pros & Cons
Provides a lot of benefits
» Potentially better latency (QoS), performance (Throughput), and
scale (Size)
» Virtual overlay allows new services to be added without penalty
– Multi-Service
– Virtualization (LANE, VPNs)
» Traffic Engineering

But
» If full “n2-squared” connectivity, limited scalability (in size)
» If partial connectivity, multiple hops may be needed across backbone
CCL/N300; Paul Huang
2017/5/25
65
ITRI
CCL

The “Overlay” Model — Edge-to-edge
Advantages

» Runs existing legacy routing protocols
over ATM (OSPF, IS-IS, RIP, etc.).
Disadvantages
» Legacy routers have imperfect topology
information about the ATM network:
» Offers investment protection and risk
avoidance for existing networks.
– An ATM net is not a single broadcast LAN.
» Uses familiar and mature technology.
– It is more than just emulated LANs.
» Segregates router implementation from
ATM implementation.
– Multiple ATM hops may be needed across
backbone.
– It is not a single link or N2 links among all routers
or just selected links.
» Routers have no existing software for SVCs.
» Is a reasonable approach for campus
backbones.
» Suboptimal; no end-to-end QoS.
» Server-based solutions raise scalability
problems.
» The Internet needs a different solution.
CCL/N300; Paul Huang
2017/5/25
66
ITRI
CCL
The “Integrated” Model
S
S
S

S
“Integrated-Model” Networks
» Routers are always in the edge of the network
» Switches are always in the core of the network
» Tags are used to identify the services required of the network
» Latency  constant

Future Enhancements
» Ipsilon IP switch, Tag Switch, ARIS, Fast IP, etc.
» MPLS standardization completion
CCL/N300; Paul Huang
2017/5/25
67
ITRI
CCL
Addressing Schemes
There are 2 Alternatives for Addressing
ATM Switches and Routers
» Peer model:
– The ATM address is treated as a logical internetwork layer address.
– An algorithm can translate between IP and ATM addresses.
– Internetwork routing done in ATM switches, which have IP addresses.
» Subnet or overlay model:
– ATM and internetworking use separate address spaces
(chosen by the ATM Forum).
– An address resolution protocol is needed.
– This decouples the efforts of the Forum and IETF.
CCL/N300; Paul Huang
2017/5/25
68
ITRI
CCL
Routing Schemes
There are 2 Ways for ATM Switch Routing
to Work with Internet Routing.
» Layered routing:
– Conventional Internet routing runs over ATM routing.
– Usually involves route or address servers.
» Integrated routing:
– ATM routing is used to support internetworking directly, or there is only one
algorithm.
– One choice: have the ATM switches run IP routing protocols.
– Another choice: have the ATM switches use forwarding tables set up in
advance by the IP routers.
¤ Note that this choice is independent of the choice of peer or subnet addressing
CCL/N300; Paul Huang
2017/5/25
69
ITRI
CCL
Gigabit Ethernet
What it use to be ?
What it has become.
What is the key ?
CCL/N300; Paul Huang
2017/5/25
70
ITRI
CCL

Ethernet - what it used to be ...
Shared Ethernet

» low cost of integration
» CSMA / CD
– homogeneous
– interoperability
– backward compatible
» 10 Mb/ s
» Half Duplex
» longevity & future proof
» Distance Limited

» Shared Bandwidth
Ease of Management
» low operations & maintenance cost
» Latency Under Heavy Loads
» minimal hidden cost
» Lack of Priority Mechanism

» Lack of Bandwidth Management
CCL/N300; Paul Huang
Ease of Installation
Cost
» 2X ~ 3X cost for 10X performance
2017/5/25
71
ITRI
CCL
Ethernet - where it is going ...

Multiple Data Rate Options
» 10 Mbps, 100 Mbps, 1000 Mbps (IEEE 802.3z Gigabit Ethernet)
» Full Duplex Option (IEEE 802.3x)
» Trunking (Cisco’s Etherchannel)
» 10,000 Mbps soon thereafter?

No Distance Limitations related to CSMA/CD or Data Rate
» Media determines distance in Full Duplex

Latencies Are Coming Down
» Very low insertion delay in Gigabit Ethernet
– 0.5 microsec for short frames
– 12 microsec for longest frames
» Very low switch latency in multi-Gigabit switches
– Under 10 microsec
– As low as 3 microsec
CCL/N300; Paul Huang
2017/5/25
72
ITRI
CCL
Ethernet - where it is going ...

Switched Ethernet Is The Norm
» Mix of 10/100/1000 Mbps ports in same box
» Switching capacities in the tens of Gigabits/sec
– Historically, ten-fold capacity increase every two years
» Cost per switched Mbps coming down
– Historically, prices dropped to 1/2 or 1/3 every two years

Scalability and Fault Tolerant Topologies
» Area of emphasis in new generation of switches
» Aggregation of traffic on multiple ports
CCL/N300; Paul Huang
2017/5/25
73
Ethernet - where it is going …
ITRI
CCL

Ethernet Switches Have Multiple Queues
» Priority of packet determines latency
» IEEE 802.1p, IETF ISSLL

Bandwidth Management Added
» Flow Control specified in IEEE 802.3x
– XON / XOFF
– Switch to Switch, or Switch to End-node Signaling
» Virtual LANs specified in IEEE 802.1q
– Frames are tagged to indicate VLAN association
– Switches interpret the tags and create campus- wideVLANs
» Advanced Filtering IEEE 802.1p - Multicast
– Protocol defined for dynamic registrations / deregistration for multicast
session - GARP/ GMRP (802.1p) and GVRP (802.1q)
CCL/N300; Paul Huang
2017/5/25
74
Networking - where it is going …
ITRI
CCL

Layer 3 Routing capabilities
» Wire-speed routing
» Performance points as high as 100X relative to traditional routers
» Eliminates the complicated “route once, switch many”
» QoS routing

Layer 3 Bandwidth Mgt.
» RSVP
» SBM
» CoS (Class of Service)
» Policy-based QoS
–
–
–
–
CCL/N300; Paul Huang
QoS Policies set centrally by network administrator
Network flows identified in real time
No changes required at the end station
No changes required to the applications
2017/5/25
75
ITRI
CCL
Networking - where is it going ...

Layer 4 switching
» Flow based switching: A flow is a stream of packets
exchanged between two (or more) users for any
application.
» Flows can be established with RSVP, CLI or SNMP
» Allows route engineering and service differentiation,
facilities that ISPs need and love to have.
» Allows fine- grained traffic control and enterprise wide
policy controls
CCL/N300; Paul Huang
2017/5/25
76
ITRI
CCL
Networking - still to come

End-to-End Standardized Congestion Management
» Beyond 802.3x Flow Control

“Contract based” Guarantees on
» Latency
» Latency Variation / Jitter
» Available bandwidth

Security
» Firewall
» SYN attack prevention
CCL/N300; Paul Huang
2017/5/25
77
ITRI
CCL
Network - standards status

IEEE Standards
» IEEE 802.3x - Standard in 1997
» IEEE 802.3z - Standard in Q3 1998
» IEEE 802.1p - Standard in Q2 1998
» IEEE 802.1q - Standard in Q3 1998

IETF Standards
» ISSLL - Integrated Services Over Specific Link Layers
– IS to IEEE 802.1p service mappings
– Layer 2 Ethernet switches will be able to participate in calladmission control and traffic policing
» IGMP for Next Generation of Layer 2 Ethernet Switches
CCL/N300; Paul Huang
2017/5/25
78
ITRI
CCL
So, is this still Ethernet ?

Preservation of the Ethernet Frame Format is Key
» Allows backward compatibility
» Enables high performance low cost switching (no need for frame
translations or segmentations)
» Best fit to what is on the majority of desktops

Other Than the Frame Format...
» It certainly is very different from the original 10Base5, coax based,shared,
CSMA/ CD Ethernet!

It is Winning Because...
» We got here through a series of pragmatic, reality based, improvements
(that took 17 years)
» Successful technologies are not about perfection, but about compromise
between complexity, performance, ease of deployment and cost
CCL/N300; Paul Huang
2017/5/25
79
ITRI
CCL
IP Switch
CCL/N300; Paul Huang
2017/5/25
80
ITRI
CCL
IP Switch -- Concept
IP Switch
IP Switch
Gateway
SYSTEM STATUS
ITRI
Ethernet to ATM Switching
CCL Hub
------------------------------------------EAS - 3000
POWER
RUN/DIAG
......
......
ATM STATUS
ETHERNET STATUS
LINE DETECT
. . . . . . P1 P2 P3 P4 P5 P6 P7 P8
Rx
Tx
COL
Rx
SIGNAL
Tx
Rx
LE
Tx
A2E
E2A
Ipsilon Flow
Management Protocol
IP Switch Controller
IP Switch
Gateway
Ipsilon Flow
Management Protocol
SYSTEM STATUS
ITRI
Ethernet to ATM Switching
CCL Hub
------------------------------------------EAS - 3000
General Switch
Management Protocol
POWER
RUN/DIAG
......
......
ATM STATUS
ETHERNET STATUS
LINE DETECT
. . . . . . P1 P2 P3 P4 P5 P6 P7 P8
Rx
Tx
COL
Rx
SIGNAL
Tx
Rx
LE
Tx
A2E
E2A
ATM
155 Mbps
ATM
155 Mbps
ATM
155 Mbps
ATM Switch
CCL/N300; Paul Huang
2017/5/25
81
ITRI
CCL
IP Switch -- Configuration
IP switching Ignores all
of the ATM Forum
Software Applications
IP
Software
ATM Forum
Software
IP
Software
MAC Layer
Transport
ATM H/W
ATM H/W
IP Switching combines
the best of IP software
and ATM H/W
CCL/N300; Paul Huang
2017/5/25
82
ITRI
CCL
Ipsilon Protocols
ATM IP Switch
IP Switch
Controller
GSMP
Upstream
Node
IFMP
ATM
Switch
IFMP - Ipsilon Flow Management Protocol



IFMP
GSMP - General Switch Management
Protocol
Protocol between multiple IP Switches or hosts
Less than 10000 lines of code
Protocol used to send flow redirection messages



CCL/N300; Paul Huang
Downstream
Node
2017/5/25
Simple protocol that provides call setup,
tear down & call status
Less than 2000 lines of code
Capable of operating with any ATM
Switch
83
ITRI
CCL


Flow vs. Connection Oriented Traffic
A Flow is a sequence of packets sent from a particular
source to a particular destination that are related in terms
of their routing and any local handling policy they may
require
It performs a similar function in a connectionless
network to the role the connection plays in a connection
oriented network.



Two packets belong to the same flow if the type of
service, protocol, source/destination addresses/ports are
the same.
short-lived traffic is ideal for forwarding
long-lived flows are ideal for "cut-through" switching
CCL/N300; Paul Huang
2017/5/25
Flow-Oriented Traffic
FTP data
Telnet
HTTP
Web Image downloads
Multimedia audio/video
Short-lived Traffic
Name Look-ups (DNS)
Simple Mail - SMTP
POP
SNMP
84
ITRI
CCL
IP Switch Operations
ATM IP Switch
ATM IP Switch
IP Switch
Controller
IP Switch
Controller
(IFMP)
Upstream
Node

(vpi/vci
= 0/15)
Downstream
Node
ATM
Switch
Upstream
Node

ATM IP Switch
ATM IP Switch
IP Switch
Controller
IP Switch
Controller
(IFMP)
Upstream
Node
CCL/N300; Paul Huang
ATM
Switch

Downstream
Node
ATM
Switch
GSMP
Downstream
Node
Upstream
Node
2017/5/25

ATM
Switch

Downstream
Node
85
ITRI
CCL
IP Switch--Campus, Departmental Backbones
Direct Attached
Servers
IP Switch of Departments
 Very-high IP throughput
 Gbps of switching performance with IP routing
functionality
 Complements existing routed networks and LAN
switching
 IP Gateway used for LAN connection
 Supports direct attached ATM servers
IP
OC-3
Switch
OC-3
IP
IP
OC-3
Switch
Switch
OC-3
OC-3
IP Switch
Gateway
10
Mbps
100
Mbps
CCL/N300; Paul Huang
OC-3
IP Switch
Gateway
10
Mbps
100
Mbps
IP Switch
Gateway
IP Switch
Gateway
10
Mbps
FDDI
Conventional
Router
100
Mbps
2017/5/25
86
ITRI
CCL

IP Switching
Approach
» Flow-driven IP switching
» Integrated routing and switching
» per-flow classification and mapping to establish dynamic shortcut paths
CCL/N300; Paul Huang
2017/5/25
87
Stated Advantages of IP Switch
ITRI
CCL

Simplicity, Flexibility, and Robustness of IP
» Discards the complexity of ATM protocols (signaling, new routing protocol,
new addressing scheme, LANE, MPOA, etc.)
» Uses well known, well debugged, and heavily tested standard IP routing
» Backward compatible to existing network and network mgt. tools

Scalability and Speed of Switching
» Uses flexible, scalable ATM hardware whose cost are decreasing rapidly
» Allows connection-less and flow-oriented traffic
» Functions like a traditional router, except 4.5 times faster throughput
» Supports QoS capability for future RSVP compatibility
» Support multicast functionality for future IP multicast services
CCL/N300; Paul Huang
2017/5/25
88
Potential Disadvantages of IP Switch
ITRI
CCL

RSVP may not be as simple or low cost
» still requires massive changes to the network
(new adapters, new switches, new routers);
(new softwares [ODI, NDIS, Winsock 2.0, etc.])
» QoS guarantees by RSVP is only a subset of ATM’s
– Only nrt-VBR
– No CBR, rt-VBR, ABR
» Requires signaling (similar to Q.2931?)
» Requires new routing protocols (not available yet)
» RSVP is not ready; 2 ~ 3 years behind ATM
CCL/N300; Paul Huang
2017/5/25
89
ITRI
CCL
MPLS (Tag) Switch
CCL/N300; Paul Huang
2017/5/25
90
ITRI
CCL
MPLS (Tag) Switching Overview
Tag Distribution Protocol
Tag Switches
(ATM Switch or Router)
Tag Edge Router
CCL/N300; Paul Huang
Existing Routing
Protocol
2017/5/25
91
ITRI
CCL
CCL/N300; Paul Huang
MPLS (Tag) Switching Example
2017/5/25
92
ITRI
CCL
Cell Interleaving Problem

Solution 1:
» Use different VPI for each label space and different VCI to maintain source
identity (unique VCI range for each ingress node)
» Limited scalability to 4096 unique VPI labels

Solution 2:
» VC Merging
CCL/N300; Paul Huang
2017/5/25
93
ITRI
CCL

MPLS (Tag) Switching
Tag Approach:
» Topology-driven, not traffic-driven
» No connection setup; prepopulate tags, distributed before traffic arrival
» Map IP traffic to a switched path via control protocol information
» Enhanced forwarding performance via label-swap paradigm
» Generalized for any media encapsulation: ATM, FR, PPP, etc.
» Agnostic to network layer services: allows any number of different network-layer
functions to map to a simple and fast forwarding mechanism
– Leverages existing routing protocol
– Multiprotocol: IPv4, IPv6, IPX
– Allows future features
CCL/N300; Paul Huang

Diffserv, RSVP, IP Multicast

CoS / QoS Routing, Policy-based Routing
2017/5/25
94
ITRI
CCL

MPLS (Tag) Switching — Pros & Cons
Advantage
» Combines L3 flexibility & scalability w/ L2 performance and traffic management
– Internal routing flexibility (OSPF)
– External routing scalability (BGP)
» Log(n) scalability
» Existing ATM networks
– Allows IP to integrate with ATM
– Integrated multi-service networks
– Reduce complexity due to multiple peer router networks
– Co-exist with ATM protocols or eliminate them all together

Potential Problem
» Loop creation due to topology changes
– Forwarding loop formed at L2 goes undetected by L3 loop mitigation mechanism
– Lack TTL field in an ATM cell header.  consumes both link and TSR resource
CCL/N300; Paul Huang
2017/5/25
95
ITRI
CCL

Potential Refinements to MPLS
Potential Refinements to MPLS
» Two-level or multi-level tags can be pushed onto a stack, and popped off as the
packet travels.
» Explicit routes can override destination-based routing for QoS or traffic
engineering.
» Flow-driven short cuts can be used at the edge, with topology-driven short cuts in
the core.

Tags or Labels can have Varying Granularity
» A tag represents a forwarding equivalence class.
» Fine granularity, for example:
– One class per address prefix in routing table or per source-destination pair
» Medium granularity, for example:
– One class for each output port in the network or for each Web URL
»
Coarse granularity, for example:
– One class for each node in the network or for each external network
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
Route Accelerator
CCL/N300; Paul Huang
2017/5/25
97
ITRI
CCL
Router Accelerator
IP
Forwarding
Switch
Router
Router
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
Route Accelerator — Advantages
No Infrastructure Impact
No new protocols
Implementation Cost
A little higher than LAN switch
Reduced Price
1/10th of router price
($500 vs. 5,000/100M port)
Increased Performance
10~20x Boost
Maximum Scalability
Routing protocols - not Spanning
Tree
CCL/N300; Paul Huang
2017/5/25
99
ITRI
CCL
Learning/Forwarding in IP Forwarding Switch
Learning:
packets from router ports
Forwarding: packets from network ports
and router ports
Network Ports
Router Ports
CCL/N300; Paul Huang
IP
Forwarding
Switch
Router
2017/5/25
100
ITRI
CCL
Sending IP Packets
Inter-Subnet
Router
Host1
Host2
 Intra-Subnet Communication
 Test under Mask is “true”.
 Next hop’s address is exactly the destination MAC
address.
 Inter-Subnet Communication
 Test under Mask is “false”.
 Next hop’s address is the router’s MAC address.
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
An Example of Inter-Subnet Communication
to destination IP: BB
Test under Mask: false
(ARP_Req)
1
2
3
4
Network
Ports
FF
aa
aa
AA
??
RR
DA2
SA2
source Ethernet address (SA3)
source IP address (SIP)
destination Ethernet address (DA3)
destination IP address (DIP)
HOST
ARP cache
IP
MAC
BB
rr
CCL/N300; Paul Huang
IP
BB
port 4
FF
aa
aa
AA
??
RR
Router
(ARP_Res)
aa
rr
aa
AA
rr
RR
port 4
cc
rr
AA
BB
MACsub port
cc
Router
Ports
port 4
rr
aa
(IP Pkt) AA
BB
HOST
send a packet
IP Forwarding Switch
IP cache
IP
Forwarding
Switch
3
2017/5/25
Router
port 3
102
ITRI
CCL
Route Once, Switch Many
switching
routing
IP
Forwarding
Switch
Router
Inter-Subnet traffic: Switched rather than Routed
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
Route Advertisements: RIP and OSPF
RFC-1388
Send RIP-1 packets in broadcast mode.
Send RIP-2 packets in broadcast mode.
Send RIP-2 packets in multicast mode.
RFC-2178
Send OSPF packets in broadcast mode.
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
IP Learning Process
if (a unicast packet && an IP packet)
learn (DIP-DA2) pair and tag proper port ID;
else
do nothing.
IP Forwarding Process
if (a unicast packet && DA2 = router’s MAC address)
lookup IP Table (cache) and forward the packet to
destination port with proper MAC substitution;
else
forward the packet to corresponding router port.
CCL/N300; Paul Huang
2017/5/25
105
ITRI
CCL
Issue of Dynamic Routing
 IN-BAND route refresh
4
3
2
1
3
IP
Forwarding
Switch
1
2
Router
4
 OUT-BAND route refresh
4
3
2
null
1
IP
Forwarding
Switch
1
CCL/N300; Paul Huang
2
3
Router
4
2017/5/25
106
ITRI
CCL
Cells-in-Frame
CCL/N300; Paul Huang
2017/5/25
107
ITRI
CCL
Cells-In-Frame Concept
Workstation
Ethernet-to-ATM CIF Edge Switch
Applications
Winsock 2.0
SIG
SIG
NULL
IP
CIF
NDIS
ATM
SHIM
Driver
ATM Functionality (QoS / Flow Control over Ethernet
ATM Cells over Ethernet Wire
Multiple ATM Cells w/ Same VC
CCL/N300; Paul Huang
2017/5/25
ATM Hdr Ethernet Hdr
108
ITRI
CCL
Cells-In-Frames Reference Model
CIF Workstations
CIF Switch
ATM Switch
ATM Workstation
Upper Layers
Upper Layers
SSCS
SSCS
CIF Mapping Function
CPCS
CIF
DLL
PHY
CCL/N300; Paul Huang
Ethernet
CIF
SAR
DLL
ATM
PHY
CPCS
SAR
ATM
ATM
PHY
2017/5/25
PHY
ATM
ATM
PHY
109
ITRI
CCL
CIF ABR Flow Control
RM Cells passed onto
Workstation at reduced rates to
convey ABR rate to SHIM,
TCP, and source
CIF Ethernet Switch
SHIM uses ABR rate from the RM cells to
control the transmission rate for each VC’s
queue and then controls TCP to send at the
same rate instead of guessing and
oscillating
CCL/N300; Paul Huang
Switch acts as a source
and destination for ABR,
turning around the RM
cells
2017/5/25
110
Functions in CIF Switches
ITRI
CCL

Signaling Functions
» The CIF switch will appear as a single device with multiple ATM
addresses, one for each of the Ethernet attached workstations

Management Functions
» The CIF switch will intercept, examine, and forward ILMI messages

Traffic Shaping Functions
» The CIF switch will act as a virtual source / virtual destination
(VS/VD) on behalf of each workstation
CCL/N300; Paul Huang
2017/5/25
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Stated Advantages of CIF
ITRI
CCL

Inexpensive and ubiquitous
» Uses existing Ethernet adapters
(saves $$)
» Large installed Ethernet base
(add new ATM software)
» Cost (CIF switches) @ Cost (Ethernet switches)

Provides ATM functionality right away.
» Guaranteed QoS over standard Ethernet
(new services)
» Allows voice over Ethernet
(saves $$)
» Allows flow / congestion control
(better than TCP/IP)
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL

Potential Disadvantages of CIF
Software SHIM (CIF driver) will hurt performance
» No pipelining to optimize performance
» Per packet interrupt results in large delays, low throughput

Requires new equipments anyway
» New CIF switches are required
– CIF switches could be as complicated as ATM switches
(requires QoS support, WFQ, ILMI, Signaling, P-NNI routing, etc.),
so may not be cheaper than Ethernet switches
» Eventually Ethernet adapters and drivers needs to be changed.
– Why not go straight to ATM adapters.
CCL/N300; Paul Huang
2017/5/25
113
ITRI
CCL
LAN Emulation
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
LAN Emulation Model
LE Configuration Server
LECS
LE Client (LEC)
LE Server (LES)
ATM Server
•Initialization
•Registration
•Address Resolution
ATM
Network
LE Client (LEC)
Broadcast & Unknown
Server (BUS)
•Data Forwarding
Bridge
LE Server (LES)
Legacy LANs
LUNI
LE Client (LEC)
Broadcast & Unknown
Server (BUS)
•Data Forwarding
ATM Server
CCL/N300; Paul Huang
•Initialization
•Registration
•Address Resolution
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ITRI
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LE Service Components
 LE Client (LEC)
* provide a MAC level emulated IEEE 802.3 or 802.5
service interface
 LE Server (LES)
* registration
* resolving MAC addresses to ATM addresses
 Broadcast and Unknown Server (BUS)
* send the broadcast MAC address frame
* send all multicast traffic
* send unicast frames (before data direct VCC has been established)
 LE Configuration Server (LECS)
* provide configuration information, address of LES
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
CCL/N300; Paul Huang
LUNI Protocol Overview

Initialization

Configuration

Joining

Registration and BUS Initialization

Data Movement
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ITRI
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CCL/N300; Paul Huang
Initialization

Must determine the ATM address of the LECS

Use SNMP ILMI to get address from a table in
the switch and place call to that address

Use well-known ATM address

If that fails, use the VPI/VCI 0/17 PVC as the
connection to the LECS

If LECS is not available, try the LES
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Configuration

LEC provides:
» ATM address
» MAC address
» LAN types and frame sizes requested

LECS returns:
» LES address
» LAN type and frame size to use
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
Joining
 Create Control Direct bi-directional VCC
 Transmit Join Request (ATM address, LAN info,
proxy indication, optional MAC address)
 Possibly accept Control Distribute VCC before
Join Response is received
 May timeout or fail
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
Registration and BUS Initialization
 Register any MAC addresses
 Resolve 0xffffffffffff MAC address to get ATM
address of BUS
 Create bi-directional Multicast Send VCC to BUS
 Accept unidirectional Multicast Forward VCC
from BUS
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
Data Movement
 When a data frame is available for transmission,
check internal cache
 If unknown, ask the LES
 While waiting for response, any transmit frame(s)
via BUS
 Establish direct connection when response is
received
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
LEC Connections across LUNI
Workstation
LEC
Config Direct VCC
Config Direct VCC
LECS
Control Direct VCC
Bridge
LEC
Control Direct VCC
LES
Control Distribute VCC
Multicast Send VCC
Multicast Send VCC
BUS
Multicast Forward VCC
Legacy LAN
Data Direct VCC
CCL/N300; Paul Huang
2017/5/25
123
ITRI
CCL
Address Resolution Frames
 IP_ARP frames (RFC 826, Nov. 1982)
IP --> 48-bit MAC address
 LE_ARP frames (ATM-Forum/LAN emulation over ATM Spec)
48-bit MAC address --> 20-byte ATM address
 ATM_ARP frames (RFC 1577, Jan. 1994)
IP --> 20-byte ATM address
CCL/N300; Paul Huang
2017/5/25
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ITRI
CCL
LE_ARP Flow
LES
LEC 1
2
A
Network
LEC 2
B
BUS
1. LEC2 sends and LE-ARP request to find ATM addr of MAC A via Control Direct VCC
2. LES does not find the corresponding ATM address of MAC A in the REG-DB
3. LES sends the LE-ARP request to all Proxies via PROXY-DB
4. Upon receiving the LE-ARP request, LEC1 looks for its filtering table to find MAC A.
LEC1 sends back the LE-ARP response with ATM LEC1
5. LES sends the LE-ARP response to LEC2 via LECID-DB
CCL/N300; Paul Huang
2017/5/25
125
ITRI
CCL
Message Flow / ATM to ATM
LES
4a, 4b
IP A
MAC A
ATM A
1
ES A
3a, 3b
2, 4
3
BUS
3c
2, 4
ES B
3
IP B
MAC B
ATM B
Control direct VCC
Multicast send VCC
Multicast forward VCC
Signalling
Data direct VCC
5, 4c
/* to find MAC B */
1. ES A sends an IP-ARP request, looking for MAC B
2. ES A sends the IP-ARP request to ES B, via BUS-ES B
3. ES B sends the IP-ARP response to ES A, via BUS-ES A
------------------------------------------------------------------------/* to find ATM addr of MAC A */
3a ES B sends LE-ARP request to find ATM addr of MAC A
3b. LES sends the LE-ARP response to ES B
3c. ES B sets up a direct VCC to ES A
CCL/N300; Paul Huang
------------------------------------------------------------------------4. ES A begins to transfer data to ES B, via BUS
/* to find ATM addr of MAC B */
4a. ES A sends an LE-ARP request to find ATM addr of MAC B
4b. LES sends the LE-ARP response to ES A
4c. ES A knew it has a direct VCC to ES B. Before using it,
ES A sends a flush message to ES B
----------------------------------------------------------------------------5. After ES A receives the ack of flush message, the data flow
is ES A-ATM network-ES B
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