UNIT VI: Advance Network Technologies
Virtualization, Software defined network, ATM (Overview, Protocol
Architecture, AAL), GMPLS, Introduction of optical networks,
Propagation of Signals in Optical Fiber, Client Layers of the Optical
Layer
8 Hrs
Monday, July 31, 2017
Virtualization: What Is Virtualization? How does it works? Background
and evolution, Advantages and disadvantages, Platform Virtualization,
Resources Virtualization, Hypervisor, Massively virtualized model-cloud.
Ref: Operating Systems—A Concept-Based Approach,
Dhamdhere, McGraw-Hill, 2008
Monday, July 31, 2017
D. M.
What is virtualization?
• Virtualization allows one computer to do the job
of multiple computers.
• Virtual environments let one computer host
multiple operating systems at the same time
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How does it work?
• Virtualization transforms hardware into software.
• It is the creation of a fully functional virtual
computer that can run its own applications and
operating system.
• Creates virtual elements of the CPU, RAM, and
hard disk.
Monday, July 31, 2017
Background and Evolution
• Virtualization arose from a need in the 1960’s to
partition large mainframe hardware.
• Improved in the 1990s to allow mainframes to
multitask.
• First implemented by IBM more than 30 years
ago.
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Virtualization
• It is divided into two main categories:
– Platform virtualization involves the simulation of
virtual machines.
– Resource virtualization involves the simulation of
combined, fragmented, or simplified resources.
Monday, July 31, 2017
Platform Virtualization
• the creation of a virtual machine using a combination of
hardware and software is referred to as platform virtualization
• Platform virtualization is performed on a given hardware
platform by "host" software (a control program), which
creates a simulated computer environment (a virtual machine)
for its "guest" software.
• The "guest" software, which is often itself a complete
operating system, runs just as if it were installed on a standalone hardware platform.
• Typically, many such virtual machines are simulated on a
given physical machine.
• For the "guest" system to function, the simulation must be
robust enough to support all the guest system's external
interfaces, which (depending on the type of virtualization)
may include hardware drivers.
Monday, July 31, 2017
Resource Virtualization
• The basic concept of platform virtualization, was
later extended to the virtualization of specific
system resources, such as storage volumes, name
spaces, and network resources.
Monday, July 31, 2017
Resource Virtualization
• Resource aggregation, spanning, or concatenation combines
individual components into larger resources or resource pools.
For example:
– RAID and volume managers combine many disks into one large logical
disk.
– Storage Virtualization refers to the process of completely abstracting
logical storage from physical storage, and is commonly used in SANs.
The physical storage resources are aggregated into storage pools, from
which the logical storage is created. Multiple independent storage
devices, which may be scattered over a network, appear to the user as a
single, location-independent, monolithic storage device, which can be
managed centrally.
– Channel bonding and network equipment use multiple links combined to
work as though they offered a single, higher-bandwidth link.
– Virtual Private Network (VPN), Network Address Translation (NAT),
and similar networking technologies create a virtualized network
namespace within or across network subnets.
– Multiprocessor and multi-core computer systems often present what
appears as a single, fast processor.
Monday, July 31, 2017
Hypervisor
• In computing, a hypervisor (also: virtual machine
monitor) is a virtualization platform that allows
multiple operating systems to run on a host
computer at the same time. The term usually
refers to an implementation using full
virtualization.
Monday, July 31, 2017
Hypervisor Types
• Hypervisors are currently classified in two types:
– Type 1 hypervisor : A software that runs directly on a given
hardware platform (as an operating system control program
Examples : VMware's ESX Server, and Sun's Hypervisor
– Type 2 hypervisor :A software that runs within an operating
system environment.
Examples include VMware server and Microsoft Virtual
Server.
Monday, July 31, 2017
Virtualization - Why Virtualize?
• Reduce Real Estate Needs
• Increase Up Time
• Reduce CO2 Emissions, Power and Cooling
Requirements
• Increase Flexibility
• Reduce Overall Costs
Monday, July 31, 2017
Massively Virtualized Model - Cloud
Monday, July 31, 2017
Cloud Computing - Services
Software as a Service - SaaS
Platform as a Service - PaaS
Infrastructure as a Service - IaaS
Monday, July 31, 2017
Advantages:
•
•
•
•
Benefits include freedom in choice of operating system.
It saves time and money.
Consolidates server and infrastructure.
Makes it easier to manage and secure desktop environments.
Disadvantages
• Only powerful computers can successfully create virtual
environment.
• Requires training to operate.
Monday, July 31, 2017
Advance Network Technologies
• Software defined network: Traditional Computer Networks,
Limitations of Current Networks, What is SDN? Background, OS
for networks, What is OpenFlow? How it helps SDN, The current
status & the future of SDN (Case studies)
• Ref: http://www.cs.princeton.edu/courses/archive/spr12/cos461/
Monday, July 31, 2017
Traditional Computer Networks
Data plane:
Packet
streaming
Forward, filter, buffer, mark,
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rate-limit, and measure packets
Traditional Computer Networks
Control plane:
Distributed algorithms
Track topology changes, compute routes,
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install forwarding rules
Traditional Computer Networks
Management plane:
Human time scale
Collect measurements and configure the
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equipment
Limitations of Current Networks
Switches
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Limitations of Current Networks
• Enterprise networks are difficult to manage
• “New control requirements have arisen”:
– Greater scale
– Migration of VMS
• How to easily configure huge networks?
Monday, July 31, 2017
Limitations of Current Networks
• Old ways to configure a network
App
App
App
Operating
System
App
Specialized Packet
Forwarding Hardware
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
App
Operating
System
App
Specialized Packet
Forwarding Hardware
App
App
Operating
System
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
Monday, July 31, 2017
App
Specialized Packet
Forwarding Hardware
Limitations of Current Networks
Feature
Feature
Operating
System
Specialized Packet
Forwarding Hardware
Million of
lines
of source
code
Billions of
gates
Many complex functions baked
into infrastructure
OSPF, BGP, multicast,
differentiated services,
Traffic Engineering, NAT, firewalls,
…
Cannot dynamically change according to network conditions
Monday, July 31, 2017
Idea: An OS for Networks
Closed
App
App
App
Operating
System
App
Specialized Packet
Forwarding Hardware
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
App
Operating
System
App
Specialized Packet
Forwarding Hardware
App
App
Operating
System
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
Monday, July 31, 2017
App
Specialized Packet
Forwarding Hardware
Idea: An OS for Networks
Control Programs
Network Operating System
App
App
App
Operating
System
App
Specialized Packet
Forwarding Hardware
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
App
Operating
System
App
Specialized Packet
Forwarding Hardware
App
App
Operating
System
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
Monday, July 31, 2017
App
Specialized Packet
Forwarding Hardware
Idea: An OS for Networks
Control Programs
Network Operating System
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Monday, July 31, 2017
Simple Packet
Forwarding
Hardware
OpenFlow/SDN tutorial, Srini Seetharaman, Deutsche Telekom, Silicon Valley Innovation Center
Idea: An OS for Networks
Software-Defined Networking (SDN)
Control Programs
Global Network View
Network Operating System
Control via
forwarding
interface
Monday, July 31, 2017
Protocols
Protocols
Software Defined Networking
• No longer designing distributed control protocols
• Much easier to write, verify, maintain, …
– An interface for programming
• NOS serves as fundamental control block
– With a global view of network
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Software Defined Networking
• Examples
– Ethane: network-wide access-control
– Power Management
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OpenFlow
• “OpenFlow: Enabling Innovation in Campus
Networks”
• Like hardware drivers
– interface between switches and Network OS
Monday, July 31, 2017
OpenFlow
Control Path (Software)
Data Path (Hardware)
Monday, July 31, 2017
OpenFlow/SDN tutorial, Srini Seetharaman, Deutsche Telekom, Silicon Valley Innovation Center
OpenFlow
OpenFlow Controller
OpenFlow Protocol (SSL/TCP)
Control Path
OpenFlow
Data Path (Hardware)
Monday, July 31, 2017
OpenFlow Switching
Software
Layer
PC
OpenFlow Client
OpenFlow Table
Hardware
Layer
MAC
src
MAC IP
dst
Src
IP
Dst
TCP
TCP
Action
sport dport
*
*
5.6.7.8
*
port 1
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5.6.7.8
*
port 2
Controller
*
port 3
port 1
port 4
1.2.3.4
35
OpenFlow Table Entry
Rule
Action
Stats
Packet + byte counters
1.Forward packet to port(s)
2.Encapsulate and forward to controller
3.Drop packet
4.Send to normal processing pipeline
5.…
Switch MAC MAC Eth VLAN IP
Port src dst type ID
Src
+ mask
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IP
Dst
IP TCP TCP
Prot sport dport
OpenFlow Examples
Switching
Switch MAC
Port src
*
MAC Eth
dst
type
00:1f:.. *
*
VLAN IP
ID
Src
IP
Dst
IP
Prot
TCP
TCP
Action
sport dport
*
*
*
*
VLAN IP
ID
Src
IP
Dst
IP
Prot
TCP
TCP
Action
sport dport
*
5.6.7.8 *
*
VLAN IP
ID
Src
IP
Dst
IP
Prot
TCP
TCP
Action
sport dport
*
*
*
*
*
*
port6
Routing
Switch MAC
Port src
*
*
MAC Eth
dst
type
*
*
*
*
port6
Firewall
Switch MAC
Port src
*
*
MAC Eth
dst
type
*
Monday, July 31, 2017
*
*
22
drop
OpenFlow
• Standard way to control flow-tables in
commercial switches and routers
• Just need to update firmware
• Essential to the implementation of SDN
Monday, July 31, 2017
ATM: Overview, Protocol Architecture, AAL, GMPLS:
Why GMPLS?GMPLS and MPLS, Control interfaces,
Challenges of GMPLS, Proposed techniques: Suggested
label, Bi-direction LSP setup, LMP, etc
Ref: 1.ATM:William Stallings, Data and Computer
Communications7thEdition
2. GMPLS: bnrg.cs.berkeley.edu/~randy/Courses/CS294.S02
Monday, July 31, 2017
WHAT’S ATM?
• ATM is Asynchronous Transfer Mode.
• ATM is a connection-oriented, high-speed, low-delay
switching and transmission technology that uses short
and fixed-size packets, called cells, to transport
information.
• ATM is originally the transfer mode for implementing
Broadband ISDN (B-ISDN) but it is also implemented
in non-ISDN environments where very high data rates
are required
Monday, July 31, 2017
BROADBAND AND B-ISDN
Broadband:
"A service or system requiring transmission channel capable of
supporting rates greater than the primary rate.“
Broadband-Integrated Service Digital Network (B-ISDN):
A standard for transmitting voice, video and data at the same time
over fiber optic telephone lines
The goal of B-ISDN is to accommodate all existing services along
with
those that will come in the future. The services that
BISDN will support include
(1) narrowband services, such as voice, voice band data, facsimile,
telemetry, videotex, electronic mail,
(2) wideband services such as T1, and
(3) broadband services such as video conference, high speed data,
video on demand. BISDN is also to support point-to-point, pointto-multipoint and multipoint-to-multipoint connectivities.
Monday, July 31, 2017
ATM OVERVIEW
• Used in both WAN and LAN settings
• Signaling (connection setup) Protocol:
• Packets are called cells (53 bytes)
– 5-byte header + 48-byte payload
• Commonly transmitted over SONET
– other physical layers possible
• Connections can be switched (SVC), or permanent (PVC).
• ATM operates on a best effort basis.
• ATM guarantees that cells will not be disordered.
• Two types of connections:
– Point-to-point
– Multipoint (Multicast)
• Four Types of Services:
– CBR (Constant Bit Rate)
– VBR (Variable Bit Rate)
– ABR (Available Bit Rate) Flow Control, Rate-based, Credit- based
– UBR (Unspecific Bit Rate) No Flow control.
Monday, July 31, 2017
ATM Characteristics
• No error protection or flow control on a link-by-link basis.
• ATM operates in a connection-oriented mode.
• The header functionality is reduced.
• The information field length is relatively small and fixed.
• All data types are the same
Monday, July 31, 2017
Why ATM?
• International standard-based technology (for interoperability)
• Low network latency (for voice, video, and real-time
applications)
• Low variance of delay (for voice and video transmission)
• Guaranteed quality of service
• High capacity switching (multi-giga bits per second)
• Bandwidth flexibility (dynamically assigned to users)
Monday, July 31, 2017
Why ATM? (con’t)
• Scalability (capacity may be increased on demand)
• Medium not shared for ATM LAN (no degradation in performance as
traffic load or number of users increases)
• Supports a wide range of user access speeds
• Appropriate (seamless integration) for LANs, MANs, and WANs
• Supports audio, video, imagery, and data traffic (for integrated services)
Monday, July 31, 2017
ATM NETWORKS
• Public ATM Network:
– Provided by public telecommunications carriers (e.g., AT&T, MCI
WorldCom, and Sprint)
– Interconnects private ATM networks
– Interconnects remote non-ATM LANs
– Interconnects individual users
• Private ATM Network:
– Owned by private organizations
– Interconnects low speed/shared medium LANs (e.g., Ethernet,
Token Ring, FDDI) as a backbone network
– Interconnects individual users as the front-end LAN for high
performance or multimedia applications
Monday, July 31, 2017
Switches in
the middle
End systems
of ATM
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File
Server
FDDI
Voice
Ethernet
Edge
Switch
Video
PBX
Private
ATM
Network
FDDI
Private
ATM
Switch
Ethernet
Token
Ring
Mainframe
Computer
Public
ATM Network
Edge
Switch
Edge
Switch
Edge
Switch
Mainframe
Computer
Video
Monday, July 31, 2017
Ethernet
Token
Ring
Video
PBX
FDDI
Voice
ATM Interfaces
Private
UNI
Public
UNI
P-NNI
•
Private
ATM WAN
Public
ATM Network
B-ICI
Private
ATM LAN
Monday, July 31, 2017
Public
ATM Network
How ATM Works?
• ATM is connection-oriented -- an end-to-end connection must be
established and routing tables setup prior to cell transmission
• Once a connection is established, the ATM network will provide end-toend Quality of Service (QoS) to the end users
• All traffic, whether voice, video, image, or data is divided into 53-byte
cells and routed in sequence across the ATM network
• Routing information is carried in the header of each cell
• Routing decisions and switching are performed by hardware in ATM
switches
• Cells are reassembled into voice, video, image, or data at the destination
Monday, July 31, 2017
User Applications
User Applications
Voice Video
Voice Video
Data
BISDN
Services
Data
BISDN
Services
Reassembly
Segmentation
Demultiplexing
Multiplexing
Workstation
Workstation
H
H
ATM Network
H
H
H
H
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H
H
H
H
H
H
H
H
B-ISDN/ATM Protocol Reference Model
Source: Stallings: Data and Computer
Communications
Monday, July 31, 2017
MPLS and GMPLS
Monday, July 31, 2017
Why MPLS?
• MPLS stands for: “Multi-Protocol Label
Switching”
• Goals:
– Bring the speed of layer 2 switching to layer 3
• May no longer perceived as the main benefit: Layer 3
switches
– Resolve the problems of IP over ATM, in particular:
• Complexity of control and management
• Scalability issues
– Support multiple layer 2 technologies
Monday, July 31, 2017
Basic Idea
• MPLS is a hybrid model adopted by IETF to incorporate best properties
in both packet routing & circuit switching
IP Router
Control:
MPLS
Control:
IP Router
Software
IP Router
Software
Forwarding:
Forwarding:
Longest-match
Lookup
Monday, July 31, 2017
Label Swapping
ATM Switch
Control:
ATM Forum
Software
Forwarding:
Label Swapping
Basic Idea (Cont.)
• Packets are switched, not routed, based on labels
• Labels are filled in the packet header
• Basic operation:
– Ingress LER (Label Edge Router) pushes a label in front of the IP header
– LSR (Label Switch Router) does label swapping
– Egress LER removes the label
• The key : establish the forwarding table
– Link state routing protocols
• Exchange network topology information for path selection
• OSPF-TE, IS-IS-TE
– Signaling/Label distribution protocols:
• Set up LSPs (Label Switched Path)
• LDP, RSVP-TE, CR-LDP
Monday, July 31, 2017
MPLS Operation
1a. Routing protocols (e.g. OSPF-TE, IS-IS-TE)
exchange reachability to destination networks
1b. Label Distribution Protocol (LDP)
establishes label mappings to destination
network
4. LER at egress
removes label and
delivers packet
IP
IP
2. Ingress LER receives packet
and “label”s packets
Monday, July 31, 2017
3. LSR forwards
packets using label
swapping
Main features
• Label swapping:
– Bring the speed of layer 2 switching to layer 3
• Separation of forwarding plane and control plane
• Forwarding hierarchy via Label stacking
– Increase the scalability
• Constraint-based routing
– Traffic Engineering
– Fast reroute
• Facilitate the virtual private networks (VPNs)
• Provide class of service
– Provides an opportunity for mapping DiffServ fields onto an MPLS label
• Facilitate the elimination of multiple layers
Monday, July 31, 2017
GMPLS
• GMPLS stands for “Generalized Multi-Protocol
Label Switching”
• A previous version is “Multi-Protocol
Lambda/Label Switching”
• Developed from MPLS
• A suite of protocols that provides common
control to packet, TDM, and wavelength
services.
• Currently, in development by the IETF
Monday, July 31, 2017
Why GMPLS?
• GMPLS is proposed as the signaling protocol for optical networks
• What service providers want?
• Carry a large volume of traffic in a cost-effective way
• Turns out to be a challenge within current data network architecture
IP
ATM
SONET/SDH
DWDM
Carry applications and services
Traffic Engineering
Transport/Protection
Capacity
• Problems:
– Complexity in management of multiple layers
– Inefficient bandwidth usage
– Not scalable
• Solutions: eliminate middle layers IP/WDM
•
Need a protocol to perform functions of middle layers
Monday, July 31, 2017
Why GMPLS? (Cont.)
• Optical Architectures
UNI
UNI
Overlay Model
Peer Model
• A control protocol support both overlay model and peer model will
bring big flexibility
– The selection of architecture can be based on business decision
Monday, July 31, 2017
Why GMPLS? (Cont.)
• What we need? A common control plane
– Support multiple types of traffic (ATM, IP, SONET
and etc.)
– Support both peer and overlay models
– Support multi-vendors
– Perform fast provisioning
• Why MPLS is selected?
– Provisioning and traffic engineering capability
Monday, July 31, 2017
GMPLS and MPLS
• GMPLS is deployed from MPLS
– Apply MPLS control plane techniques to optical
switches and IP routing algorithms to manage
lightpaths in an optical network
• GMPLS made some modifications on MPLS
– Separation of signaling and data channel
– Support more types of control interface
– Other enhancement
Monday, July 31, 2017
Control interfaces
• Extend the MPLS to support more interfaces other than packet
switch
– Packet Switch Capable (PSC)
• Router/ATM Switch/Frame Reply Switch
– Time Division Multiplexing Capable (TDMC)
• SONET/SDH ADM/Digital Crossconnects
– Lambda Switch Capable (LSC)
• All Optical ADM or Optical Crossconnects (OXC)
– Fiber-Switch Capable (FSC)
• LSPs of different interfaces can be nested inside another
PSC
TDMC
LSC
FSC
TDMC
Monday, July 31, 2017
LSC
Challenges
• Routing challenges
– Limited number of labels
– Very large number of links
• Link identification will be a big problem
• Scalability of the Link state protocol
• Port connection detection
• Signaling challenges
– Long label setup time
– Bi-directional LSPs setup
• Management challenges
– Failure detection
– Failure protection and restoration
Monday, July 31, 2017
Link Management Protocol
• Problem:
– How to localize the precise location of a fault?
– How to validate the connectivity between adjacent nodes?
• Solution: link management protocol
–
–
–
–
–
Control Channel Management
Link Connectivity Verification
Link Property Correlation
Fault Management
Authentication
Monday, July 31, 2017
GMPLS Summary
• Provides a new way of managing network
resources and provisioning
• Provide a common control plane for multiple
layers and multi-vendors
• Fast and automatic service provisioning
• Greater service intelligence and efficiency
Monday, July 31, 2017
Introduction to Optical Networks
• Telecommunications Network Architecture
• Services, Circuit Switching and Packet Switching
• Optical Networks
• The Optical Layer
• Transparency and All-Optical Networks
• Optical Packet Switching
• Transmission Basics
• Network Evolution
Propagation of Signals in Optical Fiber
• Loss and Bandwidth Windows
• Intermodal Dispersion
• Optical Fiber as a Waveguide
• Chromatic Dispersion
July 31, 2017Effects
•Monday,
Nonlinear
Client Layers of the Optical Layer
• SONET/SDH
• Optical Transport Network
• Generic Framing Procedure
• Ethernet
• IP
• Multiprotocol Label Switching
• Resilient Packet Ring
• Storage Area Networks
Ref: Rajiv Ramaswami, Kumar Shivarajan, GlanShasaki, “Optical
Networks a Practical Perspective”, Elsevier-Morgan Kaufmann
ISBN: 978-0-12-374092-2 pdf
Monday, July 31, 2017
• Thanks
Monday, July 31, 2017