ATM Protocol Analyzer for OC-3 / STM-1 and OC-12 / STM-4

ATM in a OC-3 / STM-1 OC-12 / STM-4 Network

Download ATM Protocol Analyzer for OC-3 / STM-1 and OC-12 / STM-4 Product Brochure

Overview

Asynchronous Transfer Mode (ATM) is a flexible network, which carries voice, video, and data in the same way, i.e. fixed length cells. It has generated a number of revenue opportunities because of its different classes of service support for multimedia traffic, efficient bandwidth management for burst traffic, support for LAN/WAN architecture and high performance via hardware switching.

ATM network basically has two kinds of interfaces i.e. UNI (Interface between ATM User and Public ATM switch) and NNI (Interface between two Public ATM switches). Similar to the OSI Protocol model, ATM protocol architecture has an ATM Layer as Layer 2, ATM Adaptation Layer (AAL) as Layer 3, and other higher layers depending on C-Plane, U-Plane or Layer Management Plane. User information is transferred across U-Plane and Signaling messages are transferred across C-Plane. ATM-UNI signaling is used to create and release SVCs along with a particular QoS attached to it depending bandwidth on demand.

GL's OC-3 / STM-1 OC-12 / STM-4 ATM Analyzer is used to analyze and decode different ATM protocols like ATM, AAL2 Protocols (CPS-SDU, SSSAR-SDU, and SSCS), AAL5 (CPCS), UNI and others across U plane and C plane of UNI and NNI interface.

ATM Analyzer Main Features

Displays Summary, Detail, Hex-dump, Statistics, and Call Detail views.
Summary View displays Dev #, Frame #, VPI/VCI, PT (Payload Type), HEC, OSF, AAL Type, Frame Type, CID, LI, CPI, UUI, SSSAR CID and SSCS message type, etc in a tabular format.
Detail View displays decodes of user-selected frame from the Summary View.
Hex Dump View displays raw frame data as hexadecimal and ASCII octet dump of a user-selected frame from the Summary View.
Statistics View displays statistics based on frame count, byte count, frames/sec, bytes/sec, etc for the entire capture data.
Call traces capability based on UNI signaling parameters, VPI/VCI etc.
Comprehensive ATM field based hardware filtering
CRC verification for AAL5 carrying packet data.
Support of various UNI Signaling Protocols i.e. UNI 4.0, UNI 3.1 and UNI Q-2931.
Supports software based search and filtering capabilities.
Capability to export Summary View details to comma separated values (CSV) format for subsequent import into a database or spreadsheet.
Capability to export detail decode information to an ASCII/text file.
Captures, decodes, filters, and reassembles AAL-2 and AAL-5 frames in real-time, from within the ATM cells according to user defined VPI/VCI.
Unscrambling of ATM cells based on SDH Xˆ43 + 1 algorithm.
Multiple streams of ATM traffic can be simultaneously decoded.
Streams may be captured on the selected ports.

Protocols Supported

The list of protocols that are supported by GL's OC-3 / STM-1 OC-12 / STM-4 ATM analyzer are as given below

Supported Protocols Structure for ATM Protocol Analysis

ATM Layer- B-ISDN ATM LAYER SPECIFICATION, ITU-T Recommendation I.361
ATM layer is responsible for transporting the information in the form of a fixed length cells (53 bytes) across the network using several virtual connections identified by VPI/VCI values. The connection isn't assigned a dedicated bandwidth. Depending on the QoS of involved parties, the connection is assigned a bandwidth and traffic is actually sent.
ATM Adaptation Layer (AAL)
ATM adaptation layer performs the necessary mapping between higher layer protocols and ATM layer. It multiplexes the higher layer info in the fixed length ATM cells. Because of different quality of service parameters, different types of AAL starting from AAL0 to AAL5 are defined. AAL0 is nothing but ATM cells itself. Different classes of service are mapped to individual AAL type. Among these, GL's OC-3 / STM-1 OC-12 / STM-4 ATM analyzer supports AAL2 and AAL5 as specified below:

AAL 2- Class B (ITU-T Recommendation I.363.2)
AAL 5- Class C & D (ITU-T Recommendation I.363.5)

AAL includes the following sublayers :
- SSCS (Service Specific Convergence Sublayer): ITU-T Recommendation I.366.2
  It uses AAL2 connection for transporting different narrowband traffic like Voice, CAS bits, DTMF digits, circuit mode and frame mode data etc.
- SSSAR (Service Specific Segmentation and Reassembly Sublayer): ITU-T Recommendation I.366.1
  It multiplexes frame mode data in an AAL2 connection. It fragments very large amount of data of a frame and packed in an AAL2 connection thus can assure assigned QOS for the service.
UNI
GL's OC-3 / STM-1 OC-12 / STM-4 ATM analyzer can be configured to support following UNI interfaces:
- ITU-T Standard Interfaces (UNIQ.2931):
  Q.931 based UNI signaling is an ITU-T UNI signaling standard used to establish and release of SVC. SVC is switched virtual channel created using signaling protocol when it is needed and then later on released. Various variants of UNI signaling are available.
- ATM Forum Standard Interfaces (UNI 3.0, UNI 3.1, UNI 4.0):
  Similar to Q.2931, ATM forum has defined it's own recommendations for establishment and release of SVC across ATM User-Network interface. The procedures described in these recommendations apply to both public UNI as well as private UNI.

Summary, Detail, and Hexdump Views

The ATM Protocol Analyzer application is invoked from the main menu of GL's OC-3 / STM-1 OC-12 / STM-4 ATM Analyzer for real-time analysis. The analyzer displays Summary, Detail, Hex Dump, Statistics, and Call Detail Views in different panes. The Summary pane displays Dev#, Frame#, Time, Length, Error, VPI/VCI, PT and so on. User can select a frame in Summary View to analyze and decode each frame in the Detail View. The Hex Dump View displays the frame information in HEX and ASCII format.

Protocol Summary, Detail, and Hex Dump Views in ATM Protocol Analysis

Real-time and Offline Analysis

Users can capture and analyze UNI or NNI interfaces in real-time and record all or filtered traffic into a trace file. The recorded trace file can then be analyzed offline and exported to ASCII file, and printed. User can capture raw ATM data and transmit using “Rx Packets to File” application.

Port Selection for Real-time Capture

Filtering and Search

Users can record all or filtered traffic into a trace file. Filter and search capabilities adds a powerful dimension to the ATM Analyzer. These features isolate required frames from all the captured frames in real-time, as well as offline. Users can specify VPI, VCI, and PT type values to filter frames during real-time capture. The frames can also be filtered after completion of capture according to Dev#, Frame #, Time, Length, Error, VPI/VCI, PT (Payload Type), HEC, OSF, AAL Type, Frame Type, CID, LI, CPI, UUI, and more. Similarly, search capability helps user to search for a particular frame based on specific search criteria.

Offline Filtering and Search Criteria for ATM Protocol Analysis

Real-time/Pre-Capture Filtering Criteria for ATM Protocol Analysis

Reassembly

Using reassembly option user can specify VPI /VCI values to reassemble as per the Segmentation and Reassembly rules defined by the specified AAL type. It multiplexes ATM cells as per the user specified VPI/VCI/AAL type into CPS or SAR frames. ATM cells not satisfying the user specification will be reassembled as per the default specification.

Reassembly Options for ATM Protocol Analysis

Call Detail Record and Statistics View

Call trace defining important call specific parameters like Call ID, Call disposition, Call duration, VPI/VCI, Call type (point-to-point/point-to-multipoint etc) calculated based on UNI signaling messages are displayed in Call Detail view.

Statistics is an important feature available in ATM analyzer and can be obtained for all frames both in real-time as well as offline mode. Various statistics can be obtained in Statistics View to study the performance and trend in the ATM network based on protocol fields and parameters.

Statistics Options for ATM Protocol Analysis

Enhanced Trace Saving Options

Users can control the captured trace files by saving the trace using different conventions such as trace files with user-defined prefixes, trace file with date-time prefixes, and slider control to indicate the total number of files, file size, frame count, or time limit. This feature also allows the captured frames to be saved into a trace file based on the filtering criteria set using display filter feature.

Protocol Trace Saving Options for ATM Protocol Analysis

Buyer's Guide

Item No.	Item Description
LTS204	OC-3 / STM-1 ATM Protocol Analysis
LTS304	OC-12 / STM-4 ATM Protocol Analysis
	Other Related Software
LTS200	OC-3 / STM-1 ATM Monitor, BERT, Tx/Rx Test, RAW
LTS300	OC-12 / STM-4 ATM Monitor, BERT, Tx/Rx Test, RAW
LTS201	OC-3 / STM-1 PoS Monitor, BERT, Tx/Rx Test, RAW
LTS301	OC-12 / STM-4 PoS Monitor, BERT, Tx/Rx Test, RAW
LTS202	OC-3 / STM-1 ATM and RAW Record / Playback
LTS302	OC-12 / STM-4 ATM and RAW Record / Playback
LTS203	OC-3 / STM-1 PoS and RAW Record / Playback
LTS303	OC-12 / STM-4 PoS and RAW Record / Playback
LTS205	OC-3 / STM-1 PoS Protocol Analysis
LTS305	OC-12 / STM-4 PoS Protocol Analysis
LTS206	OC-3 / STM-1 UMTS Protocol Analysis
LTS306	OC-12 / STM-4 UMTS Protocol Analysis
	Related Hardware
LTS100	Dual OC-3 / STM-1 OC-12 / STM-4 PCI Express Card
LTS105	Portable Dual OC-3 / STM-1 OC-12 / STM-4
	DDR2 Memory Options - 512 MB, 1 GB, 2 GB
	SFP Options -
	Fiber cables
	Fiber connector
	OC-3 / STM-1 OC-12 / STM-4 Monitor Parts