UNIT VI: Advance Network Technologies Virtualization, Software defined network, ATM (Overview, Protocol Architecture, AAL), GMPLS, Introduction of optical.

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

Friday, April 21, 2023

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, D. M. Dhamdhere, McGraw-Hill, 2008


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



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.


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.



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.


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 stand-alone 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.


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.


• 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.

Resource Virtualization


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.


• 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 programExamples : 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.

Hypervisor Types


Virtualization - Why Virtualize?

• Reduce Real Estate Needs

• Increase Up Time

• Reduce CO2 Emissions, Power and Cooling

Requirements

• Increase Flexibility

• Reduce Overall Costs


Massively Virtualized Model - Cloud


Cloud Computing - Services

Software as a Service - SaaSPlatform as a Service - PaaSInfrastructure as a Service - IaaS


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.


• Software defined network: Traditional Computer Networks, Limitations of Current 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/

Advance Network Technologies


Traditional Computer Networks

Data plane:Packet streaming

Forward, filter, buffer, mark, rate-limit, and measure packetsFriday, April 21, 2023


Track topology changes, compute routes, install forwarding rules

Control plane:Distributed algorithms



Collect measurements and configure the equipment

Management plane: Human time scale


Limitations of Current Networks

Switches



• Enterprise networks are difficult to manage

• “New control requirements have arisen”:– Greater scale

– Migration of VMS

• How to easily configure huge networks?


• Old ways to configure a network


Specialized Packet Forwarding Hardware

App App App


App App App


App App App


App App App


OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

App App App



Million of linesof source code

Billions of gates

Many complex functions baked into infrastructure

OSPF, BGP, multicast, differentiated services,Traffic Engineering, NAT, firewalls, …


OperatingSystem

Feature Feature

Cannot dynamically change according to network conditions


Idea: An OS for Networks


App App App


App App App


App App App


App App App


OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

App App App

Closed




App App App


App App App


App App App


App App App


OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

App App App

Network Operating System

Control Programs



Simple Packet Forwarding Hardware



Simple Packet Forwarding Hardware Simple Packet

Forwarding Hardware


Control Programs

OpenFlow/SDN tutorial, Srini Seetharaman, Deutsche Telekom, Silicon Valley Innovation Center



Global Network View

Protocols Protocols

Control via forwarding interface


Control Programs

Software-Defined Networking (SDN)


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


Software Defined Networking

• Examples

– Ethane: network-wide access-control

– Power Management


OpenFlow• “OpenFlow: Enabling Innovation in Campus

Networks”

• Like hardware drivers

– interface between switches and Network OS


OpenFlow

OpenFlow/SDN tutorial, Srini Seetharaman, Deutsche Telekom, Silicon Valley Innovation Center

Data Path (Hardware)Data Path (Hardware)

Control Path (Software)Control Path (Software)


OpenFlow

Data Path (Hardware)Data Path (Hardware)

Control PathControl Path OpenFlowOpenFlow

OpenFlow ControllerOpenFlow Controller

OpenFlow Protocol (SSL/TCP)


OpenFlow SwitchingController

PC

HardwareLayer

SoftwareLayer

OpenFlow Table

MACsrc

MACdst

IPSrc

IPDst

TCPsport

TCPdport Action

OpenFlow Client

**5.6.7.8*** port 1

port 4port 3port 2port 1

1.2.3.45.6.7.8 35Friday, April 21, 2023

OpenFlow Table Entry

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport

Rule Action Stats

+ mask

Packet + byte counters

1.Forward packet to port(s)2.Encapsulate and forward to controller3.Drop packet4.Send to normal processing pipeline5.…


OpenFlow ExamplesSwitching

*

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport Action

* 00:1f:.. * * * * * * * port6

Firewall

*

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport Action

* * * * * * * * 22 drop

Routing

*

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport Action

* * * * * 5.6.7.8 * * * port6


OpenFlow

• Standard way to control flow-tables in commercial switches and routers

• Just need to update firmware

• Essential to the implementation of SDN


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


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


BROADBAND AND B-ISDN

Broadband:"A service or system requiring transmission channel capable ofsupporting 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 linesThe 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, point-to-multipoint and multipoint-to-multipoint connectivities.


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.


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


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)Friday, April 21, 2023

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)


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


Switches inthe middle

End systemsof ATM


Public ATM Network

TokenRing

TokenRing

FDDI

FDDI

MainframeComputer

Video

Video

Video

Ethernet

Ethernet

MainframeComputer

Edge Switch

Ethernet

FileServer

PrivateATM

Switch

Edge Switch

Edge Switch

Edge Switch

PBX

PBX

Voice

Voice

Private ATM

Network

FDDI


ATM Interfaces

•

Private

UNI

Private ATM LAN

PublicUNI

Public ATM Network

Public ATM Network

B-ICI

Private ATM WAN

P-NNI


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-to-end 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


ATM NetworkH

H

H H H

H

H

H

Voice Video Data Voice Video Data

BISDNServices

BISDNServices

Reassembly

User Applications User Applications

Workstation Workstation

Multiplexing Demultiplexing

H H H HH H

Segmentation


B-ISDN/ATM Protocol Reference ModelB-ISDN/ATM Protocol Reference Model

Source: Stallings: Data and Computer Source: Stallings: Data and Computer CommunicationsCommunications


MPLS and GMPLS


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


Basic Idea• MPLS is a hybrid model adopted by IETF to incorporate best properties

in both packet routing & circuit switching

Forwarding:Label Swapping

Control:

IP Router Software

Control:

IP Router Software

Forwarding:Longest-match Lookup

Control:

ATM Forum Software

Forwarding:Label Swapping

IP Router MPLS ATM Switch


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


MPLS Operation1a. 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

2. Ingress LER receives packet and “label”s packets

IP

IP 10

3. LSR forwards packets using label swapping

IP 20IP

40

4. LER at egress removes label and delivers packet

IP


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


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


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

• 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

IP

ATM

SONET/SDH

DWDM

Carry applications and services

Traffic Engineering

Transport/Protection

Capacity


Why GMPLS? (Cont.)• Optical Architectures

• A control protocol support both overlay model and peer model will bring big flexibility– The selection of architecture can be based on business decision

Peer ModelOverlay Model

UNI UNI


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


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


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

FSCLSC

LSC

TDMC

TDMC

PSC


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


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


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


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

• Nonlinear Effects Friday, April 21, 2023

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


• Thanks


UNIT VI: Advance Network Technologies Virtualization, Software defined network, ATM (Overview, Protocol Architecture, AAL), GMPLS, Introduction of optical.

Documents

storage virtualization

resources virtualization

type of virtualization

network resources

physical storage resources

logical storage

storage pools

given hardware platform