1. Training
ATM Signaling

2. Overview What is Signaling Signaling Layers Signaling Protocol
ATM Addressing
ILMI
Signaling Setup
Practice

3. Section
What is Signaling ?

4. 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

5. 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

6. Section
What is Signaling
Signaling Layers

7. 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

8. Switched Virtual Connections (SVC)
User
SVC
Support
Upper
Layer
Applications
Q.2931/UNI
Sig Messages &
Procedures
Q.2931 Data
ATM
Adaptation
Layer
SSCOP
Q.2931 Data
SAAL
AAL5
• • • • • •
ATM
(Cell)
Layer
VPI/VCI = 0/5
Physical
Layer
SAAL: Signaling AAL
SSCOP: Service Specific Connection Oriented Protocol

9. Section
What is Signaling
Signaling Layers
Signaling Protocol

10. Simple Call Setup of a Connection
UNI
UNI
NNI
NNI
UNI
UNI
Setup
Setup
VPI/VCI
assigning
Call
VPI/VCI
assigning
Proceeding
Call
Proceeding
Connect
Connect
Connect
Ack
Connect
Ack

11. Release of a Connection
UNI
UNI
NNI
NNI
UNI
UNI
Release
Release
Release
Release
complete
Release
complete
Release
complete

12. Setup Message Elements
Connection identifier
Called party number
Calling party number
ATM user cell rate(s)
QoS parameter(s)
AAL parameters

13. UNI/Q.2931 Signaling Root Point-to-multipoint example (originator)
Leaf B
Leaf C
Leaf A
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

14. Section ATM Addressing What is Signaling Signaling Layers
Signaling Protocol
ATM Addressing

15. UNI/Q.2931 Addressing Supports multiple addressing formats
E.164 (Telephones) - 15 digits
ISO NSAP (Internet) - 20 bytes - three formats possible
Data Country Code (DCC)
International Code Designator (ICD)
Private E.164 Address
ISO = International Standards Organization
NSAP = Network Service Access Point

16. E.164 & NSAP E.164 NSAP 15 Nibbles CC NDC SN „F“ Example:
1 Byte
12 Byte
6 Byte
1 Byte
NSAP ID
Prefix
ESI
SEL
Example: A
CC: Country Code
NDC: National Destionation Code
SN: Subscriber Number
ESI: End System Identifier
SEL: Selector

17. Section ILMI What is Signaling Signaling Layers Signaling Protocol
ATM Addressing
ILMI

18. ILMI Integrated Local Management Interface (ILMI) Based on SNMP
Automatic retrieving and exchange of Interface information (UNI) between TE and a network device

19. ILMI Protocol ATM Address: ATM Address: ______.ESI Prefix.___
Cold start
Power on
Clear tables
Get address
No entry
Set Prefix
Prefix.ESI
No error
Set Address
Prefix.ESI
No error

20. Section Signaling Setup What is Signaling Signaling Layers
Signaling Protocol
ATM Addressing
ILMI
Signaling Setup

21. ATM Vision Installation
Show actual values of ATM settings:
sysconf atm
Set VP for signaling:
sysconf atm vp <Number>
Enable ILMI protocol:
sysconf atm ilmi enable
Enable ILMI polling:
sysconf atm ilmi poll

22. ATM Vision and SVC Allow point-to-multipoint (p2mp) connections:
sysconf atm p2mp enable
Set user network interface (UNI) version:
sysconf atm uni <Version>
<Version> = 3.0 | 3.1 | 4.0
Enable signaling:
sysconf atm signaling enable

23. ATM Vision and SVC Bandwidth and VPI/VCI restriction
of Line- and Cascade Interface:
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|disable
Note: If the Cascade Interface is configured to special disable,
the VCI range will be discarded

24. Setting up SVC Getting Systems ATM End System Address (AESA):
atmaddr
Setting up a video SVC:
video -s <Channel> <Bitrate> <AESA> [Flags]

25. Section Practice What is Signaling Signaling Layers Signaling Protocol
ATM Addressing
ILMI
Signaling Setup
Practice

26. Hands on: SVC

27. Trouble shooting Get Signaling trace: ps aex | grep atmsigd
ps ax | grep atmsigd
140 ? S 0:26 atmsigd -b -l syslog -q ubr:pcr=128kbps
<PID>
kill -SIGUSR2 <PID>
cat /tmp/atmsigd.<PID>.trace.<No. of Trace>