2. IP and MPLS Tunnel Introduction ISSUE 1.00

8/11/2019 2. IP and MPLS Tunnel Introduction ISSUE 1.00

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Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

IP and MPLS Tunnel

TechnologyIntroduction


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Page1Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

Foreword

With the development of the mobile network from 2G to 3G

and LTE as well, the data packet becomes the main servicein the transmission network.

The packet transmission solution can encapsulate the

various services in MPLS tunnel by PWE3 technology and

transmit them in packet mode uniformly.

The course is the basics for the further study of OptiX RTN

910/950.


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Objectives

Upon completion of this course, you will be able to:

Describe the classification of IP addresses

Describe the basic principle of IP routing

Describe the basic concepts of MPLS

Describe the MPLS tunnel (LSP) creation procedure

Outline the MPLS OAM functions


4/54Page3Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. IP Overview

2. MPLS Tunnel Technology

3. MPLS OAM

4. QinQ Overview


5/54Page4Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. IP Overview

1.1 TCP/IP Protocol Overview

1.2 IP Address Introduction and Configuration

1.3 IP Routing Overview


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TCP/IP and OSI Model

Application Layer

Presentation Layer

Conversation Layer

Transport Layer Transport Layer

Network Layer Network Layer

Data Link Layer Data Link Layer

Physical Layer Physical Layer

Application Layer

TCP/IP ModelOSI Model


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TCP/IP Protocol Stack

Physical

Layer

Data Link

Layer

Network

Layer

TransportLayer

Application

Layer

HTTP, Telnet, FTP,

TFTP, Ping, etc.

TCP/UDP

ARP/RARP

ICMPIP

Ethernet, 802.3, PPP,

HDLC, FR, etc.

Interfaces and

wires/cables

Provide application program

network interfaces

Establish terminal toterminal connection

Addressing and route

selecting

Physical media access

Binary data flow

transmission


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IP Header Format

Version

(4bits)

Header

Length

Type of Service

(8bits)

Total Length

(16bits)

Identifier

(16bits)

Flags

(3bits)

Fragmented Offset

Protocol

(8bits)

Header Checksum

(16bits)

Time to Live

(8bits)

Source IP Address

(32bits)

Destination IP Address

(32bits)

Options

(Variable Length)

88 88 88 88

32bits32bits


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IP Address

IP address is 32 bits long

Including network portion and a host portion.

Network portion

Uniquely identifies a physical or logical link and is common to all

devices attached to that link.

Host portion

Uniquely identifies a particular device attached to the link.

Generally, use dotted-decimal to represent it

For example: 10.1.1.1, 192.168.1.1, etc.


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Classification of IP Address

First Octet Rule

0

Network

(7bits) Host(24bits)

1 Network(14bits) Host(16bits)0

1 Network(21bits) Host(8bits)01

1 Multicast Address01 1

Class A

Class B

Class C

Class D

Class E

1.0.0.0~

126.255.255.255

128.0.0.0~

191.255.255.255

192.0.0.0~

223.255.255.255

224.0.0.0~239.255.255.255

240.0.0.0~

255.255.255.255 1 01 1 1 Reserved


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Private IP Address

Private IP Address

10.0.0.0~10.255.255.255

172.16.0.0~172.31.255.255

192.168.0.0~192.168.255.255


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Subnet Mask

Distinguish network portion and host portion

32-bit string, represented by dotted-decimal format

Mask for class A: 255.0.0.0

Mask for class B: 255.255.0.0

Mask for class C: 255.255.255.0

255 255 255 0

192 168 1 1192 168 1 0

AndAnd

IP address

Subnet mask

IP subnet segment


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Subnets and Subnet Masks

IP Subnet: 192.168.1.16 255.255.255.240 or 192.168.1.16/28

Subnet numbers: 2n ( n=4, 24=16)

Host numbers: 2m-2 ( m=4, 24 2 = 14)

11000000 10101000 00000001 00010001

11111111 11111111 11111111 11110000

IP address: 192.168.1.17

Network Part Subnet Part

(n bits)

Host Part

(m bits)

Subnet mask: 255.255.255.240


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IP Address Configuration

Interconnection address planning

P2P link, just 2 hosts necessary

Mask length: 30, For example: 10.1.1.0/30

Broadcast network

According to the number of hosts in this network

For example:

60 hosts in the network: 192.168.1.0/28

120 hosts in one network: 192.168.2.128/25

Device Identifier

32 bit mask length

For example: 1.1.1.1/32


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IP Routing

Route is the path information that guides packet forwarding

Routing table is the set of route information

R1

N, R1, M

Destination

Network N

Other Networks


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Routing Protocol

IS-IS (Intermediate

System to Intermediate

System)

B

C

E

D

F

A

SPF calculation

Hello

Hello

HelloHello

Hello

Hello

Hell

o

A

B

Adjacency relationship

establishment

C

E

D

F

LS

LS

L S

LS

LS

LS

L

S

A

B

Flood link state information

C

E

D

F


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Contents

1. IP Overview


3. MPLS OAM

4. QinQ Overview


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Parse IP header

mapped to next hopParse IP header

mapped to next hop

IP header is parse at each hop, resulting in low efficiency.

It is difficult to deploy QoS and the efficiency is rather low.

All routers are expected to know all routes in the entire network.

Traditional IP Forwarding

Parse IP header

mapped to next hop


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ATM Switching Process

Connection-oriented

Routing depends on link layer, based on VPI/VCI or label

Ensure QoS and real-time service

Virtual Channel Connection

(VCC)

Virtual Path Connection(VPC)

VPswitching

VCswitching

VCswitching

NNI NNI

VPI = 18

VCI = 44

VPI = 1

VCI = 1

VPI = 26

VCI = 44

VPI = 20

VCI = 30

UNIUNI


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=

Router ATM switch MPLS Router

MPLS-Multi-Protocol Label Switching

Layer 3 routing-scalable and flexible

Layer 2 switching-high reliability and traffic engineeringmanagement

Technology Combination

+


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MPLS Introduction

MPLSMulti-Protocol Label Switching

Multi-Protocol Support various layer 3 protocols, such as IP, IPv6, IPX, SNA

Label Switching

Label the packet, forward packets by label switching instead of IP

forwarding


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MPLS Basic Concepts

LSR: Label Switch

Router

LER: Label Edge Router

LSP: Label Switch Path

LER

LER

LER

LERLSR LSR

LSR

MPLS domain

IP

MPLS

LSP

Non-MPLSdevice

Non-MPLSdevice


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MPLS Basic Concepts (Cont.)

FEC----Forwarding Equivalent Class

Set of data flows with the same attributes. These data flowsare processed in the same way by LSRs during transmission.

FECs are identified by the address, service type, and QoS.

During IP forwarding through the longest match algorithm,

packets with the same destination belong to an FEC.


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MPLS Packet

MPLS packet header locates between layer2 and layer3

L2 Header L3 Header L3 PayloadMPLS Label

Label Exp S TTL

0 19 22 23 31


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MPLS Label Stacking

IP L1 IP IPL2 IPL2L3 IPL2L4 IPL2

MPLS Domain

MPLS nested Domain

MPLS

header

Layer2

headerIP header Data

MPLS

header

IP


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Tunnel Technology

The point to point tunnel provides the path for data

transparently transmission.

OptiX RTN 910/950 can form the tunnel by

MPLS LSP

QinQ

Tunnel

A B C D


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MPLS tunnel technology

LSP

Ingress Egress

Core LSR

MPLS domain

Transit Transit

LER LER

IP network IP network

Core LSR

LSP includes the static LSP and dynamic LSP.


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MPLS Label Operations

Label operations include push, swap and pop.

Pus

hSwap

Swap Pop

LER

LER

IP

IP

L1 IP

L2 IP

L3 IP


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Creating the Static LSP

Static LSPs are manually created by users to assign labels

for each forwarding equivalence class (FEC) .

The principle followed in manually assigning labels:

The value of the OUT label on a node is the value of the IN

label on the next node.

Ingress Transit Egress3.3.3.3/32


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Creating the Dynamic LSP

Dynamic LSP is set up automatically by the signaling

protocol.

In OptiX RTN 910/950, RSVP allocates LSP tunnel labels.

Packet forwarding module

Create LSP

Frame

Create LSP

Message diffuse

Frame

Link State

database

TE

database

IGP routing LSP selection

Signaling

module

IS-IS routingMessage diffuse


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MPLS Label Forwarding

In the MPLS domain, there is a static LSP to the IP host

3.3.3.3/32

A

(ingress)3.3.3.3/323.3.3.3/32

100200300

F

G I

H

E

B

(transit 1)

C

(transit 2)

D

(egress)

Eth0 Eth0 Eth2 Eth1 Eth2 Eth0 Eth3


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MPLS Label Forwarding Table

For the former static LSP to the IP host 3.3.3.3/32, the

MPLS label forwarding table in A, B, C, D are:

Node IN interface IN label OUT interface OUT label (next hop)

A (Ingress) FEC

3.3.3.3/32

B (Transit1) Eth0 300 Eth2 200

C (Transit2) Eth1 200 Eth2 100

Eth0

push Eth0 300

D (Egress) 100 Eth3 pop


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MPLS Label Forwarding

The MPLS forwarding for the former FEC

IngressIngress Transit1Transit1 Egress

EgressTransit2Transit2

3.3.3.3/323.3.3.3/32

100200300

IP Packet

To:3.3.3.3

Push Swap Swap Pop

IP Packet

To:3.3.3.3

Label:300

IP Packet

To:3.3.3.3

Label:200

IP Packet

To:3.3.3.3

Label:100IP Packet

To:3.3.3.3

Eth0 Eth0 Eth2 Eth1 Eth2 Eth0 Eth3


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Node BRNC

The MPLS tunnel application in OptiX RTN 910/950:

MPLS Tunnel Application


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MPLS TTL Processing

Uniform Mode

MPLS DomainMPLS Domain

CECE PEPE PP PEPE CECE

IP TTLIP TTL

255255IP TTLIP TTL

254254

MPLSMPLS

TTL254TTL254

MPLSMPLS

TTL254TTL254

IP TTLIP TTL

254254

MPLSMPLS

TTL253TTL253

IP TTLIP TTL

252252


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MPLS TTL Processing (Cont.)

Pipe Mode

CECE PEPE PP PEPE CECE

IP TTLIP TTL255255

IP TTLIP TTL254254

MPLSMPLS

TTL100TTL100

MPLSMPLSTTL100TTL100

IP TTLIP TTL254254

MPLSMPLS

TTL100TTL100

IP TTLIP TTL253253

MPLSMPLSTTL 99TTL 99


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Summary

Background of the MPLS

MPLS concepts: LER, LSR, LSP, FEC MPLS label structure and label stacking

MPLS tunnel technology: ingress, transit, egress, push,

swap, pop, static LSP, dynamic LSP, MPLS Label

Forwarding

MPLS TTL processing

C


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Contents

1. IP Overview


3. MPLS OAM

4. QinQ Overview

C t t


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Contents

3. MPLS OAM

3.1 MPLS Tunnel Failure Detection

3.2 MPLS OAM

MPLS Pi


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MPLS Ping

MPLS ping is used for LSP failure detection

5.5.5.5/325.5.5.5/32 4.4.4.4/324.4.4.4/32

MPLS Echo Request message (TTL:255)

MPLS Echo Request reply

1.1.1.0/301.1.1.0/30 3.3.3.0/303.3.3.0/302.2.2.0/302.2.2.0/30

Tunnel (LSP)Tunnel (LSP)

MPLS T t


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MPLS Traceroute

MPLS traceroute is used for LSP failure locating

1.1.1.0/301.1.1.0/30 3.3.3.0/303.3.3.0/302.2.2.0/302.2.2.0/30

5.5.5.5/325.5.5.5/32 4.4.4.4/324.4.4.4/32

Tunnel (LSP)Tunnel (LSP)

Echo Request (TTL:1)

Echo reply


Echo reply


Echo reply

F ti f MPLS OAM


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Functions of MPLS OAM

MPLS OAM must realize the following functions:

MPLS OAM provides on-demand and continuous connectivity

verification of LSPs to confirm that faults do not exist on the monitored

LSPs.

If a fault occurs, MPLS OAM must detect, diagnose, and locate the

fault, notify the NMS of the fault, and take actions appropriate to the

fault type.

MPLS OAM functions must be backward compatible.

MPLS OAM has the capability to measure the availability and network

performance of an LSP and provide information for user accounting.

MPLS OAM P k t


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MPLS OAM Packets

MPLS OAM packets can be classified into three types:

Connectivity verification packets

CVConnectivity Verification

FFDFast Failure Detection

FDI (Forward Defect Indication) packets

BDI (Backward Defect Indication) packets

Connectivity Verification Packets


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Connectivity Verification Packets

CV Detection

For the CV detection on the egress, the egress sets a sliding

window to 3 seconds and judges the LSP status according to

the CV packet received in the sliding window.

FFD Detection

For the FFD detection on the egress, the egress sets a sliding

window as three times as the interval for sending the FFD

packet and judges the LSP status according to the FFD packet

received in the sliding window.

Backward Defect Indication


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Packets MPLS OAM BDI Detection Case

Source LSR

Transit LSR

Transit LSR

Sink LSR

CV/FFD

14:OAM Alert

LSP Out-label

BDI

14:OAM Alert

LSP Out-label

backwar

d tunnels

Questions


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Questions

Whats the difference between CV packet and FFD packet?

Contents


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Contents

1. IP Overview


3. MPLS OAM

4. QinQ Overview

Ethernet Frame Structure


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Ethernet Frame Structure

Ethernet_II

DMAC SMAC Length/T DATA/PAD FCS

Length/Type Mean

Length/T > 1500

Length/T


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VLAN Application

VLAN 2 VLAN 1

VLAN 1 VLAN 2

Ethernet frame

with VLAN tag 1

Ethernet framewith VLAN tag 2

Ethernet frame

without VLAN flag

DA SA TPID (8100) VLAN Ethernet Data

2 N266

VLAN Frame


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Application Scenario of QinQ


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Application Scenario of QinQ

Summary


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Summary

IP address classification and application

MPLS basic concepts and tunnel technologies

MPLS failure detection and OAM functions

QinQ application


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Documents

2. IP and MPLS Tunnel Introduction ISSUE 1.00