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Training ATM Signaling

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Training

ATM Signaling

Overview

– What is Signaling– Signaling Layers– Signaling Protocol– ATM Addressing– ILMI– Signaling Setup– Practice

Section

What is Signaling ?

What is Signaling?

• Mechanism by which users identify to whom they want to be connected

• Dynamic on-demand method for customers to communicate, the type of connection desired and the attributes of the connection

• Signaling is a “Control Plane” function that “automates” setting up a connection Predefined VCI = 5 Uses AAL5

• Signaling, in conjunction with Call Processing in conjunction with Traffic Management and subscriber information, allocates the VPI/VCI to be used for the connection and communicates this back to the user

Switched Virtual Connections (SVC)

Call Processing

Why SVCs?

Flexible connectivity

More efficient resource utilization

Automated

Transparent to User

Signaling channel predefined as VCI = 5

Messages (Q.2931 layer 3 protocol) exchanged from User to Switch Call Processing to request & setup connection

Section

Signaling Layers

What is Signaling

Assured Information Transfer

• AAL 1, 2 & 5 do not provide assured transfer (eg. re-transmission in the event of error)

• SSCOP (Service Specific Connection Oriented Protocol) uses sequence numbers and other controls to acknowledge or effect re-transmission of messages

• SSCOP can be placed above AAL 3/4 or 5

• SSCOP is example of SSCS (Service Specific Convergence Sublayer) protocol

• Used with signaling for reliable connection establishment and support reliable communications about a connection

Switched Virtual Connections (SVC)

UserSVC

SupportQ.2931/UNISig Messages &

Procedures

UpperLayer

Applications

PhysicalLayer

ATM(Cell)Layer

ATMAdaptation

Layer

Q.2931 Data

VPI/VCI = 0/5

SAALSSCOP Q.2931 Data

AAL5 • • • • • •

SAAL: Signaling AAL SSCOP: Service Specific Connection Oriented Protocol

Section

Signaling Protocol

What is Signaling

Signaling Layers

Simple Call Setup of a Connection

Connect Ack

Setup

SetupCall

ProceedingCall

Proceeding

Connect

ConnectConnect Ack

NNINNIUNIUNI

UNIUNI

VPI/VCIassigning VPI/VCI

assigning

Release of a Connection

Release

Releasecomplete

NNINNIUNIUNI

UNIUNI

Release

Releasecomplete

Release

Releasecomplete

Setup Message Elements

• Connection identifier

• Called party number

• Calling party number

• ATM user cell rate(s)

• QoS parameter(s)

• AAL parameters

UNI/Q.2931 Signaling

Root(originator)

Leaf A

Leaf B

Leaf C

Unidirectional information flow

Distributed tree topology using ATM switch multicast function

Rapid connection setup supported

Dynamic adding and clearing of endpoints

Signaling messages in VCI = 5

Procedures similar to ISDN Q.931 but simplified

Point-to-multipoint example

Section

ATM Addressing

What is Signaling

Signaling Layers

Signaling Protocol

UNI/Q.2931 Addressing

ISO = International Standards OrganizationNSAP = Network Service Access Point

Supports multiple addressing formats

E.164 (Telephones) - 15 digitsISO NSAP (Internet) - 20 bytes - three formats possible

Data Country Code (DCC)International Code Designator (ICD)Private E.164 Address

E.164 & NSAP

SNNDCCC

15 Nibbles

E.164

ID

CC: Country Code NDC: National Destionation Code SN: Subscriber Number ESI: End System Identifier SEL: Selector

„F“

Example: 00049 2407 95860 F

NSAP Prefix ESI SEL

12 Byte 6 Byte1 Byte 1 Byte

47 0049240795860005320A4801 005066000028 00Example:

Section

ILMI

What is Signaling

Signaling Layers

Signaling Protocol

ATM Addressing

ILMI

Integrated Local Management Interface (ILMI)

Based on SNMP

Automatic retrieving and exchange of Interface information (UNI) between TE and a network device

ILMI Protocol

Power on Cold startClear tables

ATM Address: ATM Address:

______.ESI Prefix.___

Get address

No entry

Set Prefix

No error

Prefix.ESI

Set Address

No errorPrefix.ESI

Section

Signaling Setup

What is Signaling

Signaling Layers

Signaling Protocol

ATM Addressing

ILMI

ATM Vision Installation

sysconf atm

Show actual values of ATM settings:

sysconf atm vp <Number>

Set VP for signaling:

sysconf atm ilmi enable

Enable ILMI protocol:

sysconf atm ilmi poll

Enable ILMI polling:

ATM Vision and SVC

sysconf atm p2mp enable

Allow point-to-multipoint (p2mp) connections:

sysconf atm signaling enable

Enable signaling:

sysconf atm uni <Version><Version> = 3.0 | 3.1 | 4.0

Set user network interface (UNI) version:

ATM Vision and SVC

Bandwidth and VPI/VCI restrictionof Line- and Cascade Interface:

root@Karlsruhe:/> sysconf port ?usage: sysconf port sysconf port show sysconf port line pcr <pcr>|link sysconf port casc pcr <pcr>|link|none sysconf port casc vpi any sysconf port casc vpi <min> <max> sysconf port casc vci any sysconf port casc vci <min> <max> sysconf port casc special enable|disableroot@Karlsruhe:/>

Note: If the Cascade Interface is configured to special disable, the VCI range 0..31 will be discarded

Setting up SVC

video -s <Channel> <Bitrate> <AESA> [Flags]

Setting up a video SVC:

atmaddr

Getting Systems ATM End System Address(AESA):

Section

Practice

What is Signaling

Signaling Layers

Signaling Protocol

ATM Addressing

ILMI

Signaling Setup

Hands on: SVC

INFAN

ETHERNET 2 ETHERNET 1

IN

ASI

OUT1 OUT2

ASI

RX

SO

RA

TX

LO

LP

L IN E IN TE RFA CE

I N O U T

OUT1 OUT2

ASI

INFAN

ETH ER N ET 2 ETH ER N ET 1RX

SO

RA

TX

LO

LP

L IN E IN TE R FA C E

I N O U T

O U T 1 O U T 2

A S I

SD

Catalyst8500

Power Supply 0CISCO YSTEMSS Power Supply 1

SwitchProcessor

SERIES

Trouble shooting

Get Signaling trace:

ps aex | grep atmsigd

kill -SIGUSR2 <PID>

cat /tmp/atmsigd.<PID>.trace.<No. of Trace>

root@Karlsruhe:/> ps ax | grep atmsigd 140 ? S 0:26 atmsigd -b -l syslog -q ubr:pcr=128kbps root@Karlsruhe:/>

<PID>