Veraz ControlSwitch Product Description

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ControlSwitch Product Description

Release 5.5.5

Version 1.0

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Veraz Networks, Inc. 926 Rock Ave., Suite 20 San Jose, CA 945131

Phone: (408) 750-9400 E-mail: [email protected] www.VerazNetworks.com

Veraz Networks ControlSwitch and the Veraz Networks corporate logo are trademarks of Veraz Networks, Inc.

All other trademarks are the property of their respective owners.

Information in this document is subject to change without notice. November, 2005

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Table of Contents

Preface

Audience . . . xii

Assumptions. . . xii

Organization . . . xii

Documentation Set . . . .xiii

Online Documentation. . . xiv

Documentation Conventions . . . xv

Contact Information . . . xvi

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1 Introduction

Introduction . . . .1-2

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2 New Functionality Added in Release 5.5.5

EMS Enhancements . . . .2-2 EMS Disaster Recovery. . . .2-2 Event Relay Server . . . .2-2 Combined EMS CDR Platform . . . .2-2 Bulk Provisioning Enhancements . . . .2-2 Operational Tools . . . .2-2 Test Call . . . .2-2 IN Services . . . .2-3 INAP CS-1. . . .2-3 SIP Enhancements . . . .2-3 SIP High Availability Solution . . . .2-3 Session Timer Compliance . . . .2-3 Answer Offer Model . . . .2-3 Prack Method. . . .2-4 Tel URL Compliance . . . .2-4 Update Method . . . .2-4 Hong Kong ISUP Compliance . . . .2-4

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3 ControlSwitch Solutions

ControlSwitch Solutions . . . .3-2 Packet Toll/Tandem Solution . . . .3-2 Integrated Voice-Data Access for Businesses . . . .3-4 SIP Internet Working Services . . . .3-5 H.323 Internet Working Services . . . .3-7 Universal Port RAS Gateway Control . . . .3-8 Internet Call Diversion/Off Load . . . .3-10 Voice-Data Traffic Groomer . . . 3-11

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4 Veraz ControlSwitch General Description

General Description . . . .4-2 Signaling Gateway . . . .4-3 Signaling Gateway Variants. . . .4-3 Call Control Element . . . .4-4 Service Execution Element . . . .4-4 Policy Element . . . .4-6 Events Collector . . . .4-7 CDR Element . . . .4-7 Element Management System . . . .4-8 IP Call Element . . . .4-8 SS7 Access Server . . . .4-9 ControlSwitch Element Interactions . . . .4-9 Scalability for Large Networks . . . .4-12

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5 Supported Customer Environments

Class 4/5 Switch Interfaces . . . .5-2 PBX and RAS / NAS Device Interfaces . . . .5-2 STP Interfaces . . . .5-3 IP Network Interfaces . . . .5-4

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6 Supported ControlSwitch Configurations

Supported ControlSwitch Configurations . . . .6-2 Recommended ControlSwitch Element Configurations: Elements and Platforms . . . .6-2 Redundant System Recommendations. . . . . . .6-3 SG Redundancy . . . .6-3 CCP/CCE Redundancy . . . .6-3 SEE Redundancy . . . .6-4 PE Redundancy . . . .6-4 EC Redundancy . . . .6-4 EMS Redundancy . . . .6-4

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7 EMS and ControlSwitch Infrastructure

System Startup and Upgrade . . . .7-2 Software Upgrades. . . .7-2 Software Optionality Control (SOC) . . . .7-2 EMS High Availability - Disaster Recovery . . . .7-3 Combined EMS and CDR Platform. . . .7-3 System and Element Provisioning . . . .7-4 User Management: Privileges, Actions, Roles. . . .7-5 User Management . . . .7-6 EMS GUI Menu Access Control . . . .7-6 Role Management . . . .7-6 Audit Log. . . .7-7 Currently Logged in Users. . . .7-7 Security Management . . . .7-7 Secure Shell . . . .7-7 DS0 Level Management. . . .7-7 Fault Management . . . .7-8 Alarm Severities . . . .7-9 Pending Alarm View . . . .7-9 Operator Actions . . . .7-10 Alarms Aggregation. . . .7-10 Alarm Filtering and Sorting. . . .7-10 Operator Settable Alarm Properties. . . 7-11 Alarm History View. . . 7-11 Email Notification for Alarms . . . .7-12 Element Status View . . . .7-12 Test Call . . . .7-13 Performance Management . . . .7-14 Periodic Monitoring. . . .7-14 Reports . . . .7-16 Report Descriptions . . . .7-19 Call Tracing . . . .7-22 Oracle DB Space Monitoring and Disk Usage Monitoring. . . .7-23 System Logs Enhancements . . . .7-24 SNMP Northbound Interface . . . .7-25 SNMP Management of Media Gateways . . . .7-25 Event Relay Server . . . .7-26 Automated Provisioning . . . .7-29

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PL/SQL API for Third Party Management Control . . . .7-29 Routing Bulk Provisioning Feature . . . .7-29

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8 SS7 Services

Overview . . . .8-2 SS7 Services. . . .8-2 SS7 MTP Level 2. . . .8-2 SS7 MTP Level 3. . . .8-2 SS7 ISUP . . . .8-3 Overlap Signaling . . . .8-6 ISUP Segmentation . . . .8-7 Message and Parameter Compatibility . . . .8-7 Availability Control . . . .8-8 Connection Fallback . . . .8-9 Auto Repeat Attempt . . . .8-10 Propagation Delay . . . 8-11 ETSI V1 Modeling . . . .8-14 Country Specific ISUP Variant Support . . . .8-15 Mexico . . . .8-15 UK ISUP . . . .8-16 Romanian ISUP . . . .8-16 Russian ISUP . . . .8-16 Singapore ISUP . . . .8-16 Hong Kong ISUP. . . .8-16 SS7 IN Services - North America . . . .8-17 ControlSwitch Local Number Portability Implementation . . . .8-18 SS7 INAP Services . . . .8-19 Productized Services . . . .8-19 Global Title Support . . . .8-22 Supported Variants and Limitations . . . .8-22 Ulticom Signaling Gateway Limitations . . . .8-23 Telesys Signaling Gateway Limitations . . . .8-23 ISUP and TCAP Support . . . .8-24

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9 ISDN-PRI Services

Features Supported for ETSI and NI-2 Variants of ISDN-PRI . . . .9-2 ISDN-PRI Messages Supported by ControlSwitch . . . .9-3 ISDN-PRI Maintenance Operations Supported by ControlSwitch . . . .9-3 Q.SIG Services. . . .9-4 Q.SIG Trunk Group Provisioning . . . .9-4 Q.SIG Messages and Information Elements . . . .9-5

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10 CAS Services

CAS Services . . . .10-2 MF Signaling . . . .10-2 DTMF Signaling . . . .10-2 Signaling Protocols . . . .10-2 Wink Start . . . .10-3 Immediate Start . . . .10-3 Basic PBX . . . .10-3 Feature Group D . . . .10-3 ANI Over CAS . . . .10-4

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11 SIP Services

SIP Services . . . 11-2 Target Applications & Services . . . 11-2 General SIP Architecture . . . 11-3 SIP Load sharing fail-over and route distribution . . . 11-5

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12 Policy Element - Supported Policies

Routing. . . .12-2 Re-Routing . . . .12-2 Provisioning Interface . . . .12-2 Re-Route Triggers . . . .12-2 Re-Route Treatments . . . .12-3 Announcements . . . .12-3

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13 Routing and Digit Analysis

Digit Analysis and Digit Collection. . . .13-2 Parameters in DA. . . .13-3 Translations, Call Routing, and Routing Plans . . . .13-5 Numbering Plan Format . . . .13-5 Call Type Determination . . . .13-5 Routing and Screening - Plans, Policies, and Parameters . . . .13-6 Route Advance Capability . . . .13-17 VoIP Protocol Routing . . . .13-17 Local Gateways, ICE Platforms, and ICE Processes. . . .13-18 IP Trunk Groups . . . .13-19 H.323 Routing . . . .13-19 OSP Routing . . . .13-20 SIP Routing . . . .13-20 Route Advance. . . .13-21 Enhanced Routing Feature . . . .13-21 Variable Support . . . .13-21 Settable Parameters . . . .13-24 Mark as Billable. . . .13-25 Skip Routing . . . .13-25 Satellite Aware Routing . . . .13-25 Translates To Feature. . . .13-26 Class of Service . . . .13-26 Release Cause Override After Announcements . . . .13-27

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14 Supported Services

Service Trigger Plan Group Interface . . . .14-2 Supported Service Trigger Treatment types . . . .14-2 Policy Execution . . . .14-3 Account Code Services . . . .14-3 Provisioning . . . .14-4 Personal Toll Free . . . .14-5 Provisioning . . . .14-5 Security Toll Free . . . .14-5 Provisioning . . . .14-6 C Tone Service . . . .14-6 Tariff Announcements . . . .14-6 International Dialing Service Using Voice Menu . . . .14-8 Collect Call . . . .14-10 Software Optionality Control (SOC) for Services . . . .14-12

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15 Lawful Intercept Solution for Tandem

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16 Call Processing

Test Line Operations . . . .16-2 T100 Test Line Operation . . . .16-2 T102 Test Line Operation . . . .16-2 T108 Test Line Operation . . . .16-2 Media Gateway Support. . . .16-3 ControlSwitch / Media Gateways VoIP Interoperability . . . .16-3 ControlSwitch / Media Gateways PSTN Interoperability . . . .16-4 AudioCodes Mediant 2000 Support . . . .16-5 VoIP and Related Protocol Conformance . . . .16-6 MGCP . . . .16-6 ISDN User Adaptation - IUA . . . .16-6 Stream Control Transmission Protocol - SCTP . . . .16-7 MTP3 User Adaptation (M3UA). . . .16-7 H.323 Support and Interworking . . . .16-7 H.323 OSP SIP Originating and Terminating IP Address . . . .16-8 H.323 Reconnect Feature. . . .16-8 Session Manager Protocol . . . .16-9 Reliable UDP - RUDP . . . .16-9 SIP Support . . . .16-9

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17 ControlSwitch High Availability

Overload Protection . . . .17-2 Network Failure . . . .17-2 SS7 Network Failure . . . .17-2 IP Network Redundancy between Veraz ControlSwitch Elements . . . .17-3 IP Network Redundancy between ControlSwitch and Media Gateway . .17-4 Element/Device Failure . . . .17-5 SIP High Availability Solution. . . .17-6

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18 Billing and Event Collector

Event Collection. . . .18-2 Overview of Event Data . . . .18-2 CDR Manager . . . .18-3 iCDR: Veraz CDR . . . .18-3 BAF CDR Generation . . . .18-5 Record Format . . . .18-5

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Preface

This guide provides an introduction to the ControlSwitch and its architecture. The following topics are included in this preface:

• Audience • Assumptions • Organization • Documentation Set

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Veraz Networks ControlSwitch Product Description

Audience

This guide is written for system administrators, engineers and operators who will install and administer the Veraz Networks ControlSwitch.

Assumptions

Users of this guide must be familiar with telecommunications networks and monitoring equipment.

Organization

This guide is organized as follows:

• Chapter 1, “Introduction”, provides an introduction to the new ControlSwitch func-tionality.

• Chapter 2, “New Functionality Added in Release 5.5.5”, provides details on new func-tionality added in this release.

• Chapter 3, “ControlSwitch Solutions”, provides details on the ControlSwitch solu-tions.

• Chapter 4, “Veraz ControlSwitch General Description”, providesa general description of the Veraz ControlSwitch

• Chapter 5, “Supported Customer Environments”, describes the supported customer environments for the ControlSwitch.

• Chapter 6, “Supported ControlSwitch Configurations”, provides details on the supported ControlSwitch configurations.

• Chapter 7, “EMS and ControlSwitch Infrastructure”, describes the EMS and

ControlSwitch Infrastructure.

• Chapter 8, “SS7 Services”, describes SS7 Services.

• Chapter 9, “ISDN-PRI Services”,describes ISDN-PRI services. • Chapter 10, “CAS Services”, describes CAS services.

• Chapter 11, “SIP Services”, describes SIP services.

• Chapter 12, “Policy Element - Supported Policies”, describes the Veraz Networks supported PE policies.

• Chapter 13, “Routing and Digit Analysis”, provides details on Digit Analysis and Routing.

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• Chapter 14, “Supported Services”, provides details on all supported services. • Chapter 15, “Lawful Intercept Solution for Tandem”, describes the Veraz Networks

Lawful Intercept solution.

• Chapter 16, “Call Processing”, provides details on call processing.

• Chapter 17, “ControlSwitch High Availability”, provides details on the Veraz Network high availability solutions.

• Chapter 18, “Billing and Event Collector”, provides details on Billing and Event Collector.

• Glossary of terms • Index

Documentation Set

The ControlSwitch documentation set includes the following publications: • ControlSwitch Product Description

The ControlSwitch Product Description provides an description of the ControlSwitch features and functionality.

• ControlSwitch System Requirements and Environment Guide

The ControlSwitch System Requirements and Environment Guide provides hardware, software, and network requirements information.

• ControlSwitch Installation Guide

The ControlSwitch Installation Guide provides instructions on how to install, upgrade and re-install ControlSwitch.

• ControlSwitch Provisioning Guide

The ControlSwitch Provisioning Guide provides instructions on how to provision a new ControlSwitch (initial provisioning).

• ControlSwitch Reference Guide

The ControlSwitch Reference Guide provides information and field definitions for the all EMS screens.

• ControlSwitch Lawful Intercept Guide

The ControlSwitch Lawful Intercept Guide provides information on the Veraz Networks Lawful Intercept solution and configuration details..

• ControlSwitch Maintenance Guide

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Veraz Networks ControlSwitch Product Description

• EMS Disaster Recovery Guide

The EMS Disaster Recovery Guide provides detailed instructions for the Veraz Networks Disaster Recovery feature.

• ControlSwitch Release Notes

The ControlSwitch Release Notes provide information on new features, changes from the previous release, and any known issues.

• ControlSwitch Patch Release Notes

The ControlSwitch Patch Release Notes provide information on issues, resolved from the previous release, and instructions on how to apply the patch.

Online Documentation

The following PDF files of the ControlSwitch documentation guides that make up the

ControlSwitch documentation set can be found in the /cdrom/cdrom0/doc directory:

• pdd.pdf • environment.pdf • install.pdf • provision.pdf • reference.pdf • maintaintenance.pdf • lidap.pdf • disasterrecovery.pdf • relnote.pdf • patch.pdf

After installation of your ControlSwitch software, these same PDF files of the

ControlSwitch documentation guides that make up the ControlSwitch documentation set

can be found by selecting Documents from the Veraz View login display shown in the following figure.

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Online Documentation

Note To view PDF format files, you must have an Adobe Acrobat Reader.

See http://www.adobe.com for information on obtaining the Adobe Acrobat

Reader software.

Documentation Conventions

The following typographical and style conventions are used in this guide.

Table 2-1 Typographical Conventions

Convention Description

italics Emphasis, or variable values in command line or code examples.

courier font Command line or code examples, directory names, paths, and filenames used in text.

< > Variable values in command line or code examples. Initial Capitals Buttons, icons, menu items, field names, components

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Veraz Networks ControlSwitch Product Description :

Contact Information

For more information about Veraz Networks, please contact us: Veraz Networks, Inc.

926 Rock Avenue, Suite 20 San Jose, CA 945131

Phone: (408) 750-9400 E-mail: [email protected]

Web: http://www.VerazNetworks.com.

Technical Assistance Centers (TACs) USA Tel: +1-214-6473397 Email: [email protected] Israel Tel: + 972-3-9287077 Fax: +972-3-9268999

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Chapter 1

Introduction

This chapter provides an introduction to Veraz Networks.The following topics are covered:

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Veraz Networks ControlSwitch Product Description Chapter 1: Introduction

Introduction

Veraz Networks, the leading independent softswitch vendor provides a best-of-class solu-tion that meets the challenge of converging current and future telecommunicasolu-tions capa-bilities onto a single Multi-Service Access Network.

Communication service providers face a complex set of challenges. Worldwide deregula-tion has increased the level of competideregula-tion, forcing service providers to find new

approaches to attract and retain profitable customers. While the ubiquity of the Internet has resulted in new opportunities for interactions with anyone, anywhere, the new compet-itive environment and the rise of the Internet has reduced the profitability potential of the traditional public voice network. At the same time, businesses and consumers are moving towards always-on digital connectivity through broadband and Web-enabled wireless devices to better take advantage of this connected world. These digitally empowered users are increasing the demand for customized communication services. Service providers require new efficiencies to serve today's Internet users and new flexibility to attract and retain tomorrow's profitable broadband users. To succeed, service providers must over-come the technical and financial hurdles of moving to increasingly efficient packet-based technologies and services while still leveraging existing circuit-switched voice networks. In an environment replete with vendors offering two-tier and three-tier vertical solutions, Veraz Networks has elected to concentrate the full weight of their experience and effort toward the development of next generation softswitch solutions. Veraz Networks is committed to providing open and interoperable solutions consistent with the intent of the IETF, ITU, the International Softswitch Consortium, and other proponents of distributed architecture principles and systems concepts. The Veraz Networks softswitch provides a true best-of-class solution meeting all of the requirements of the complete next generation three-tiered reference model.

At the media transport level, the Veraz I-Gate 4000 media gateways and media device partners provide toll quality transmission of voice and fax traffic between the packet network and the PSTN. For the control and signaling level, the Veraz ControlSwitch and its suite of applications provide fully distributed softswitch functionality that transforms the traditional central office into a distributed “Network Office.” The resulting complete solution makes possible the deployment of flexible subscriber services from anywhere in the service provider's network, lowering network investment and operating costs. As a result, the service provider can quickly deliver high-value, differentiated new services for their specific markets boosting their revenues and profits.

The Veraz ControlSwitch is a next-generation carrier-class softswitch system that empowers service providers to rapidly deploy new, revenue-generating services, while providing a smooth migration path from existing voice networks to next-generation packet networks. Built around distributed, highly scalable, high availability architecture with open interfaces to media devices, application servers and back-office systems, the Veraz

ControlSwitch platform acts as an operating system for the new public network. The same ControlSwitch can be used to deploy multiple solutions as described in the following

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Veraz Networks' world-class engineering team brings together voice and data expertise drawn from leading service providers, telecommunications companies and data

networking companies. Veraz Networks is privately funded by leading venture capital firms, Kleiner Perkins Caufield & Byers, Norwest Venture Partners and Battery Ventures. The company is headquartered in San Jose, CA.

Veraz Networks' products provide far-reaching advantages to a service provider in the migration of their public voice networks to more efficient and flexible packet technology based networks. While capitalizing on existing installed infrastructure investments the service provider is able to solve current network challenges and prepare to capture new revenue opportunities through a new generation of differentiating services.

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Veraz Networks ControlSwitch Product Description Chapter 1: Introduction

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Chapter 2

New Functionality Added in

Release 5.5.5

This chapter provides an introduction to the new functionality added in release 5.5.5 to the

ControlSwitch.The following topics are covered:

• EMS Enhancements

• EMS Disaster Recovery • Event Relay Server

• Combined EMS CDR Platform • Bulk Provisioning Enhancements • Operational Tools

• Test Call • IN Services

• INAP CS-1 • SIP Enhancements

• SIP High Availability Solution • Session Timer Compliance • Answer Offer Model • Prack Method • Tel URL Compliance • Update Method

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Veraz Networks ControlSwitch Product Description Chapter 2: New Functionality Added in Release 5.5.5

EMS Enhancements

EMS Disaster Recovery

This feature allows for the ControlSwitch to offer a cold standby EMS system for disaster recovery scenarios. The high availability solution relies on Oracle Dataguard RDBMS 9.2. Using dataguard, the EMS will receive updates from the EMS of all configuration infor-mation at regular intervals (settable from real-time to periodic) to allow for an activity switch at any time.

Event Relay Server

The Event Relay Server (ERS) is a software module that is loaded on the ControlSwitch. It allows third-party applications - Event Monitoring Agents (EMA) to subscribe to and receive call related events over a TCP connection. Multiple EMAs can subscribe to a receive events. All events are encoded in XML

This functionality is typically deployed with back office traffic monitoring systems that want to track real time call status. Alternately, this application can also be used by opera-tors wishing to record traffic patterns in real-time.

Combined EMS CDR Platform

EMS and CDR processes can now be combined on one Sun Solaris platform. Two data-base instances will reside on this combined platform; one for high transaction rate CDR process and the other for persistent EMS process. Veraz will advise whether a network topology allows having such a platform depending on call rate and size of network.

Bulk Provisioning Enhancements

Bulk provisioning enhancements in Release 5.5.5 provides an efficient way to reduce routing data loading time when provisioning Policy Engine. This feature will reduce data loading time by replacing current policy data with new data provided in an excel file

Operational Tools

Test Call

Test call support allows the operator the ability to place an on demand test call from the EMS GUI. This is effectively an inverted call setup between two endpoints for the purposes of operational testing of a given circuit or trunk group. Initial support is for SIP and ISUP based protocol permutations.

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INAP CS-1

IN Services

INAP CS-1

Release 5.5.5 adds ETSI INAP CS-1 capability with three productized services for imme-diate deployment;

• Pre-paid authentication

• Toll Free/Free Phone applications • Local Number Portability

All announcements for services are based on an IP Media Server servicing as an SRF function under MGCP control.

SIP Enhancements

Release 5.5.5 adds a number of enhancements for SIP to provide a carrier grade SIP solu-tion. The enhancements also extend the compliance of Veraz SIP solusolu-tion.

SIP High Availability Solution

High Availability is offered in release 5.5.5 for Veraz SIP solution to address network, process, and hardware failures. This feature addresses both local and remote failures. The feature uses standard SIP procedures like Session Timer, Redirect and OPTIONS methods based on standard RFCs.

Session Timer Compliance

Session Timer is used basically for session pings as well as High Availability solutions. Session Timer compliance has been added to release 5.5.5. Previously, Veraz SIP gateway (Local Gateway) did accept Session Timer requests.

In release 5.5.5, Veraz SIP IP Trunk Groups can be configured to send Session Timer Requests to remote SIP entities. The implementation complies with RFC4028.

Answer Offer Model

Answer Offer Model as recommended by RFC 3264 suggests methods of exchanging multimedia capabilities (SDP) between two endpoints until a resolution is reached. Employing Answer Offer Model an endpoint can either offer or request SDP in an INVITE message. In subsequent messages the other endpoint can respond to the offer. More exchanges can happen until the call is established using provisional messages or provisional messages responses (18X and Prack).

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Veraz Networks ControlSwitch Product Description Chapter 2: New Functionality Added in Release 5.5.5

Prack Method

SIP Messaging comprises provisional and final responses to an INVITE message. The provisional responses are not mandatory in a call flow. Provisional responses are used for alerting and ringing an endpoint e.g. 180 Alerting, 183 Session Progress (18X). The final response is 200 OK. Acknowledging a final response 200 OK using ACK is mandatory but acknowledging provisional messages is optional. A provisional message is acknowl-edged using PRACK (abbreviated for Provisional Acknowledge).

Release 5.5.5 implements PRACK message accepting as well as generation per standard RFC 3262. In previous releases, PRACK is only sent out by Veraz when requested by remote entity.

Tel URL Compliance

Per SIP standard RFC2806, Tel URL specifies that a PSTN phone ('tel'-ephone) is being used for SIP calls. URLs are used to `locate' resources, by providing an abstract identi-fication of the resource location. Every SIP call is addressed to a SIP URL that like an email comprises user name or number like sip:[email protected]. Similar, Tel URL looks like tel:[email protected].

Tel URL feature is particularly used when interworking with PSTN network. Many scenarios using Tel URL are defined in RFC3398. Release 5.5.5 supports tel URL format.

Update Method

Update Method is implemented in release 5.5.5 per SIP standard RFC 3311. UPDATE allows a client to update parameters of a session (such as the set of media streams and their codecs) but has no impact on the state of a dialog. In that sense, it is like a re-INVITE, but unlike re-INVITE, it can be sent before the initial INVITE has been completed. This makes it very useful for updating session parameters within early dialogs.

Veraz uses update both in High Availability solution as well as Answer- Offer Model. UPDATE behavior can be configured on per trunk group basis.

Hong Kong ISUP Compliance

Hong ISUP compliance is provided in release 5.5.5 per ITU Q.764, Q.762, Q.784.1 and HKTA2202 Issue 3. Veraz SS7 framework is being leveraged to provide Hong Kong Variant support. With this support, service providers will be able to connect with domestic Hong Kong SS7 traffic.

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Chapter 3

ControlSwitch Solutions

The ControlSwitch is an open standards based multi protocol, multi solution converged service platform.The following topics are included in this chapter:

• ControlSwitch Solutions • Packet Toll/Tandem Solution

• Integrated Voice-Data Access for Businesses • SIP Internet Working Services

• H.323 Internet Working Services • Universal Port RAS Gateway Control • Internet Call Diversion/Off Load • Voice-Data Traffic Groomer

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Veraz Networks ControlSwitch Product Description Chapter 3: ControlSwitch Solutions

ControlSwitch Solutions

The ControlSwitch is an open standards based multi protocol, multi solution converged service platform. All functionality enabled by the ControlSwitch is available in the product and does not require different software for each application. To enable a new feature, it only need be configured in the network. Consequently, service providers can add new features and solutions without having to run multiple disparate networks or incur downtime to reconfigure the network. They only need enable the new feature and add any processing capacity needed for the new traffic load.

Packet Toll/Tandem Solution

Figure 3-1: Veraz ControlSwitch Packet Toll/Tandem Solution

The Veraz ControlSwitch Packet Toll/Tandem Solution enables routing of tandem and long-distance voice traffic over a packet network, while seamlessly interoperating with today's PSTN. This allows service providers to alleviate congestion in their traditional PSTN network and cap their investment in legacy infrastructure, while enabling conver-gence to a single, more cost-effective packet network for both voice and data traffic. The Veraz ControlSwitch provides the call control, routing and signaling needed for VoIP/ ATM internet working with both SS7 IMTs and ISDN-PRI or CAS trunks (for PBX enter-prise locations or in markets where IMTs are unavailable to the service provider). Thus, using this solution, service providers can route voice calls on a call-by-call basis over a traditional TDM network or a packet network and offer revenue-generating long-distance services and direct access ISDN-PRI or CAS connections to enterprise customers.

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The open, multi-vendor architecture of the Veraz ControlSwitch provides service providers with the flexibility to deploy best-of-breed media gateways from multiple vendors. In addition, advanced routing capabilities - including support for LNP, 8XX/ Toll-free services, Voice VPN and national numbering plans - combined with multi-national SS7/PRI signaling support enable deployment of long-distance voice services over national and/or multi-national packet networks. Policy-based routing and screening and XML-based Digit Analysis provide a high level of flexibility and customization in deploying these services. Open interfaces to third-party application servers combined with simple web-based tools enable rapid creation and deployment of new enhanced services over a packet network. Call detail records are generated and made available in a very flex-ible format for integration with carrier billing and network performance evaluation systems. A robust, production-ready management system with a web-based GUI and open management interfaces based on SNMP, PL/SQL API and CORBA provides the opera-tional support needed for large-scale deployments.

Key Benefits:

• Significantly lower costs through convergence to a common packet network for voice and data services

• Advanced routing capabilities to immediately enable revenue-generating toll/ tandem services

• Multi-national SS7/PRI signaling support to enable global VoIP/ATM network deployment

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Integrated Voice-Data Access for Businesses

Figure 3-2: Veraz ControlSwitch Integrated Voice-Data Access for Businesses

The Veraz Networks solution for Integrated Voice-Data Access, based on the Veraz

ControlSwitch softswitch platform along with Integrated Access Devices (IADs) and

high-density Media Gateways (MGs) from multiple partner vendors, enables integration of enterprise voice and data traffic onto a common packet network right from the customer premises. Voice and data traffic is integrated using an IAD at the customer premises in conjunction with existing PBXs and Key Systems. On-net calls between different loca-tions are routed through the packet network. Calls that need to go off-net are routed to a media gateway that provides connectivity to the PSTN through SS7 IMTs, ISDN PRIs or CAS trunks. Routing policies can be defined to keep off-net calls within the packet network as long as possible. The multi-vendor IADs and media gateways are both controlled by the Veraz ControlSwitch, which allows for both flexibility and cost-effec-tiveness in deploying best-of-breed solutions. Advanced routing features including policy-based routing, Voice VPN, 8xx (toll-free) dialing and LNP are supported for both on-net and off-net calls. Open interfaces to third-party application servers and application devel-opers enable rapid creation and deployment of new enhanced services over a packet network.

This solution leverages existing voice infrastructure in business locations by supporting a number of different interfaces (CAS, PRI, Analog Trunks, etc.) from the IADs to existing PBXs and Key Systems. On the network side, the IADs support several different WAN interfaces such as E1/T1, NxE1/T1, SDSL and ADSL, thus enabling service providers to target both small/medium and large business segments. Furthermore, the addition of appli-cation servers to support Line-side Services enables extension of integrated voice and data services to smaller branch locations and remote sites without a PBX.

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Key Benefits:

• High-margin, high-value bundled voice and data services for enterprises

• Significantly lower costs through converged packet network right from customer premises

• Investment protection for legacy PBX systems

• Seamless evolution to extend integrated voice and data services to smaller branch locations without PBX

• Built on open, multi-service, carrier-grade Veraz ControlSwitch platform

SIP Internet Working Services

Figure 3-3: Veraz ControlSwitch SIP Internet Working Services

Through open interfaces to multi-vendor SIP-based network elements including applica-tion servers, proxy servers and SIP end-points, the Veraz ControlSwitch enables service providers to broaden the set of enhanced communications services available to their busi-ness and residential customers. Leveraging the standards-based SIP interfaces of the Veraz ControlSwitch platform, service providers can rapidly deploy enhanced services such as IP Call Centers, IP Conferencing, Unified Messaging and Pre-paid/Calling Card Services, leading to new revenue opportunities, enhanced customer retention and compet-itive differentiation.

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Veraz ControlSwitch's unique ability to mediate between various packet and circuit-based protocols such as MGCP, H.323, SIP, H.248 and global PSTN signaling variants gives service providers the flexibility to deliver a wide variety of enhanced services to

subscribers served through any type of network. For instance, an IP Conferencing service provided by a SIP-based application server can be offered to SIP devices served by SIP networks, H.323 clients served by H.323 networks, POTS phones connected to broadband IADs and to POTS phones served by the PSTN. This allows service providers to deploy a common services infrastructure for service delivery over different types of networks, leading to lower costs, wider market reach and uniformity of service for all subscribers In addition to support for basic SIP call control messages, the ControlSwitch SIP interface also supports enhanced SIP call control messages to enable advanced features such as third-party call control from SIP servers. Furthermore, the ControlSwitch SIP interface also offers connectivity to SIP proxy servers serving SIP end-points and support for SIP-to-SIP calls between two independent SIP networks thus allowing them to be controlled and billed using a single platform.

Veraz Networks has created a SIP-based application server toolkit that has enabled its application server partners to quickly achieve full interoperability between their products and the ControlSwitch platform. The toolkit includes an interoperability specification, SIP call flows for interoperation between application servers and the Veraz ControlSwitch, and an interoperability testing process that supports remote testing via the Internet followed by in-lab testing of the complete solution. By expediting the interoperability testing process with multi-vendor application servers, this toolkit empowers service providers to rapidly respond to changing customer needs and exploit new revenue oppor-tunities.

Key Benefits:

• High-margin enhanced services deployment leveraging SIP application servers from multiple vendors

• Improved customer acquisition, customer retention and competitive differentia-tion through delivery of enhanced services

• Common infrastructure for delivery of services to subscribers served through different types of networks - leading to lower costs, wider market reach and uniformity of service across multi-protocol, multi-vendor networks

• SIP-based application server toolkit to expedite interoperability testing with appli-cation servers, enabling rapid response to new customer needs and revenue oppor-tunities

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H.323 Internet Working Services

Figure 3-4: Veraz ControlSwitch H.323 Internet Working Services

The Veraz ControlSwitch solution for H.323 Internet working seamlessly bridges existing H.323 networks to more scalable MGCP/ SS7-based networks and to emerging SIP and H.248-based networks, with no changes or upgrades required to the H.323 networks. This seamless interworking is accomplished using a unique approach that makes the

ControlSwitch appear as an H.323 Gateway to H.323 Gatekeepers that are already in

place. For service providers with existing H.323 networks, this solution enables them to efficiently scale their networks while protecting their existing investments. For carriers without existing H.323 networks, this enables inter-carrier traffic exchange with other carriers who have H.323 networks. For instance, a carrier building a highly scalable MGCP-based VoIP network with PSTN/SS7 connectivity could generate revenues by providing long distance transport and origination/termination services to regional H.323-based service providers.

In addition, this solution supports interworking with H.323-based feature servers for delivery of enhanced services such as Unified Messaging, IP Call Centers and Presence Services. Thus, by leveraging the Veraz ControlSwitch's ability to mediate between various packet and circuit-based protocols, service providers can offer H.323-based enhanced services to users on H.323 networks as well as to users on MGCP-based networks, H.248-based networks, SIP networks or the PSTN. The ControlSwitch supports a standard H.323-based application interface that allows for rapid integration, testing and deployment of new application servers.

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Key Benefits:

• Seamless migration from H.323 networks to more scalable MGCP/ SS7-enabled and to emerging H.248 and SIP-based networks; provides investment protection • Revenue-generation through long distance transport services to regional

H.323-based service providers

• High-margin enhanced services deployment using H.323 application servers • Built on open, multi-service, carrier-grade ControlSwitch platform

Universal Port RAS Gateway Control

Figure 3-5: Universal Port RAS Gateway Control: Integrated Dial-up Access and

VoIP Services

Until now, supporting both dial-up access and voice applications required two separate networks for both access and transport. In traditional circuit-switched access networks, explosive growth in dial-up access has led to increasing congestion of Class switches, requiring increased investments in expensive circuit-switched infrastructure along with massive Remote Access Server (RAS) farms. In the backbone, voice and data traffic is typically transported over different overlay networks resulting in large capital and opera-tional costs. The Veraz ControlSwitch, in conjunction with new or upgraded RAS with Universal Port capabilities, provides a cost-effective, next-generation solution that allows service providers to deploy a more efficient common network infrastructure for both dial-up access and VoIP Toll/Tandem applications.

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Service providers currently offering dial-up access can leverage their existing RAS infra-structure and point-of-presence (POP) space to offer new VoIP services and expand their market coverage. By off loading dial-up data traffic from congested Class switches and by enabling routing of voice traffic over a packet network, this ControlSwitch solution allows service providers to cap investment in legacy infrastructure, rapidly enter new markets without additional Class-switch expenditures and evolve to a converged packet network for both voice and data traffic. Leveraging the universal port capabilities of partner gate-ways, this solution provides call-by-call support for any service - data, voice or fax - on any gateway port, thus leading to more efficient use of network infrastructure and invested capital.

The open, multi-vendor, multi-service architecture of the ControlSwitch provides service providers with the flexibility to deploy the optimal combination of gateways for each application and target market. For instance, service providers can deploy universal port-enabled RAS gateways in some markets for modem wholesale and VoIP Tandem applica-tions, while deploying high-density media gateways in other markets for VoIP wholesale and PRI off load applications. With both types of gateways being controlled by the Veraz

ControlSwitch, a common management, operations and billing infrastructure can be more

easily leveraged.

Advanced routing capabilities - including support for Voice VPN, LNP, 8XX/Toll-free services and multi-national numbering plans - combined with multi-national PSTN/SS7 signaling support enable deployment of carrier-grade VoIP services over national and/or multi-national packet networks. Open interfaces to third-party application servers and application developers combined with simple web-based tools enable rapid creation and deployment of new enhanced services over a packet network.

Key Benefits:

• Leverages existing RAS infrastructure for new revenue-generating voice over IP services, in addition to modem wholesale services

• Significantly lower costs through convergence to a common packet network for voice and data services

• Alleviates congestion and caps investment in legacy TDM infrastructure

• Open, multi-vendor, multi-service ControlSwitch architecture that allows choice of optimal gateway for different market segments and enables seamless evolution to support new services

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Internet Call Diversion/Off Load

Figure 3-6: Veraz ControlSwitch Internet Call Diversion/Off Load

Explosive growth in data dialup traffic over the last few years has led to increasing congestion in the existing circuit-switched voice network. This has led to increased call blocking requiring large investments for more circuit-switched infrastructure. The Veraz

ControlSwitch Internet Call Diversion (ICD) solution provides a cost-effective

next-generation solution to this problem. By off loading dial-up data traffic from congested local tandem and Class switches, the ControlSwitch ICD solution enables service providers to extend the life of their installed infrastructure, expand services in existing markets and rapidly enter new markets without additional Class-switch expenditures. The

ControlSwitch ICD solution delivers two different lucrative services that can be offered to

ISPs: Modem Wholesale Services and PRI Leasing Services.

Modem Wholesale Services:

In this application, dial-up data traffic over SS7 IMTs is routed directly to a partner Remote Access Server (RAS) under control of the Veraz ControlSwitch. The

ControlSwitch provides the call control and signaling needed for the RAS to terminate the

SS7 IMTs. This enables service providers to enter new markets and offer modem whole-sale services to ISPs at a fraction of the cost of legacy infrastructure, while alleviating congestion in their existing Class switches.

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PRI Leasing Services:

In this application, dial-up data traffic over SS7 IMTs is routed to a partner media gateway under control of the Veraz ControlSwitch. The ControlSwitch provides the call control and signaling needed for the media gateway to terminate SS7 IMTs and switch the data calls onto PRIs going to an ISPs RAS. This enables service providers to offer PRI leasing services to ISPs in new markets at a fraction of the cost of legacy infrastructure, while leveraging the ISPs' existing RAS infrastructure.

Key Benefits:

• Immediate revenue generation through modem wholesale and PRI leasing services to ISPs

• Alleviates congestion and caps investment in legacy TDM infrastructure • Investment protection for existing RAS infrastructure

• Open, multi-service, carrier-grade ControlSwitch architecture that enables seam-less evolution to support new services

Voice-Data Traffic Groomer

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Explosive growth in data dialup traffic over the last few years has led to increasing congestion in the existing circuit-switched voice network. This has led to increased call blocking requiring significant new investments for additional circuit-switched infrastruc-ture. The Veraz ControlSwitch Voice-Data Traffic Groomer Solution provides a cost-effective next-generation solution to this problem. The Veraz ControlSwitch in conjunc-tion with a partner media gateway (MG) off loads data traffic from the PSTN before it hits a legacy TDM switch and forwards the voice traffic to a circuit switch or PBX for further processing. This solution enables calls on any type of ingress trunk (IMT, PRI, CAS) to be routed over any type of egress trunk (IMT, PRI, CAS). Voice and Data traffic coming in over IMTs can be groomed into PRI data traffic going to ISPs, PRI or CAS voice traffic going to enterprise PBXs and voice traffic over IMTs to a TDM switch.

This solution enables service providers to offer lucrative PRI/CAS services for voice and PRI services for data. PRI/CAS services for voice enable a Direct Access Line offering to enterprise customers with a PBX. PRI wholesale services for data enable an Internet Call Diversion offering to ISPs. Advanced routing capabilities like 8XX/Toll-free services, LNP, policy-based routing and screening and XML-based Digit Analysis are supported for both voice and data calls.

Furthermore, with an upgrade to the Veraz ControlSwitch Packet Toll/Tandem Solution, voice traffic can also be selectively routed to a VoIP/ATM packet network, thereby enabling convergence to a next-generation packet network for both voice and data.

Key Benefits:

• Immediate revenue generation through low-cost PRI data offering for ISPs and PRI/CAS voice offering for enterprise customers

• Alleviates congestion and caps investment in legacy TDM infrastructure • Open, multi-service, carrier-grade ControlSwitch architecture that enables

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Chapter 4

Veraz ControlSwitch General

Description

This chapter provides a general description of the Veraz ControlSwitch. The following topics are included in this chapter:

• General Description • Signaling Gateway • Call Control Element • Service Execution Element • Policy Element

• Events Collector • CDR Element

• Element Management System • IP Call Element

• SS7 Access Server

• ControlSwitch Element Interactions • Scalability for Large Networks

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Veraz Network ControlSwitch Product Description Chapter 4: Veraz ControlSwitch General Description

General Description

The Veraz ControlSwitch product is a distributed software system that executes on a number of SUN computer hardware (typically carrier-grade SUN Netra platforms) plat-forms interconnected over an underlying IP data network. The ControlSwitch is designed with a highly scalable architecture. A service provider can elect to start with a small system and grow it to a very large one, spanning multiple geographic centers, by adding components as the traffic and end-user volume increases. At a high level the

ControlSwitch can be described as a distributed IP-network-based system providing

tradi-tional switch functions of call control, call routing, signaling gateway, and media device control in addition to back office functions in support of provisioning, billing, and network operations. The ControlSwitch consists of several software elements:

• Signaling Gateway (SG), • Call Control Element (CCE), • Policy Element (PE),

• Events Collector (EC),

• CDR Element (CDRE) or CDR Manager • Element Management System (EMS). • IP Call Element (ICE)

• Service Execution Element (SEE)

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Signaling Gateway Variants

A brief description of each ControlSwitch element follows. Further operational details are available later in this document.

Signaling Gateway

The Signaling Gateway (SG) allows the ControlSwitch system to access and utilize the STP and SCP resources of the SS7 network for PSTN call signaling and for intelligent networking services. These resources are available at two levels.

Signaling Gateway Variants

The ControlSwitch supports multiple signaling gateways to suit various applications. The two types are as follows:

Ulticom Signaling Gateway

There are two types of Ulticom Signaling Gateways: ISUP and TCAP. Both an ISUP and a TCAP SG can be configured to reside on the same SG platform.

The ISUP Signaling Gateway in combination with a CCE performs trunk side signaling for the purpose of call setup and tear down. This pair of elements receives ISUP messages from the SS7 network and acts as an SSP in the ControlSwitch system. The CCE is then able to process call setup, maintenance, and tear down for the local side as well as for the remote side via these ISUP messages. The SG supports multiple SS7 variants. The details of these supported variants are discussed later in this document.

The TCAP Signaling Gateway acts as a conduit for SS7 TCAP messages to a Service Control Point (SCP) in the PSTN network. The ControlSwitch gains access to the PSTN SCP resident databases via TCAP and provides select AIN line services such as toll-free translations (in North America also referred to as 8xx number translations) and local number portability using the AIN 0.1 call model.(Extensions to support ETSI compatible intelligent network services are in development.)

For variant support and limitations, please see the SS7 Services section.

Telesys Signaling Gateway

The Telesys signaling gateway is used in conjunction with the ControlSwitch M3UA support. The Telesys iSTP interfaces to the SS7 network through TDM A-links and F-links. It terminates MTP layer 1, 2, and 3 traffic. ISUP traffic is then forwarded to the

ControlSwitch via M3UA.

Logically, the iSTP functions as the SG/SGPs with respect to M3UA and communicates with the Veraz SS7 Access Server (SAS), which contains as the AS/ASPs.

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The Telesys iSTP are deployed in a redundant pair, with each pair representing a physical point code. Logically the iSTP can represent multiple point codes hence appearing as an STP to the network if required. This allows for more efficient use and management of the network resources. The Telesys iSTP functions as an STP only for the point codes managed by the ControlSwitch. It does not function as a standalone STP for legacy switches.

From the perspective of the SS7 network, the iSTPs local point code is seen as the adja-cent point code for routing to all configured point codes supported by a given A-link or F-link pair. Upon receiving messages for a logical point code, the iSTP will forward hem to the appropriate M3UA ASP based on the configured routing key. For more information, please see the section on the ControlSwitch SS7 Application Server (SAS).

For variant support and limitations, please see the SS-7 Services section.

Call Control Element

The Call Control Element (CCE) resides on a platform called the Call Control Platform (CCP). The CCE provides protocol processing and resource management functions that allow call legs to be controlled within the system however does not manage the state machines for the calls and services. In short, the CCEs primary responsibilities fall into the following categories;

• Protocol Processing

• Protocol mediation between network facing protocols (MGCP, ISDN, SS7 etc.) and the internal generic call processing protocol

• Resource Management (TGs, channels, gateways, etc.)

The CCE interfaces with the Signaling Gateway, Service Execution Element, Policy element, Element Management System, Event Collector and media gateways via an IP network. The Call Control Element supports a variety of protocols both for PSTN signaling as well as packet network signaling.

Service Execution Element

The Service Execution Element is a SLEE compliant services execution environment. Utilizing the Veraz Services Execution Environment (SEE), enhanced user services can be realized and rapidly brought to market. The SEE follows the same modular and distributed architecture as that currently used in the ControlSwitch for tandem services. Developed in C++ and XML, the SEE is optimized for performance to allow more efficient processing over a Java based solution however follows all architectural considerations of the industry accepted J-SLEE specification.

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The SEE is similar to the existing ControlSwitch elements in that it is a modular compo-nent that can be added to the network as required by the operator. It follows the same distributed design as has been production proven in numerous networks, guaranteeing maximum availability and unlimited scalability.

The SEE uses a C++ engine with flexible adapters allowing the ControlSwitch interface with both next generation and legacy external service platforms. This includes:

• Legacy Signaling • SS7 • PRI • CAS • IP protocols • H.323 • SIP • MGCP

The direct protocol interface to the network is via the CCE which mediates the messages to a generic inter-call call processing language that the SEE uses for service execution. This allows the SEE to operate as a protocol agnostic engine hence services can be created irrespective of the underlying framework. Effectively generic inter-call call processing language and clean separation of call control and services function through the SEE allow the ControlSwitch to support a completely programmable services model. On other hand, protocols interworking get more flexible too. Since it is no longer dependent on call / services model, new protocol addition or protocol modification requires only development / modification of adapter.

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Figure 4-2: SEE Architecture

Integrated services include:

• Tandem State machine for equivalent pre 5.5 functionality • Re-Routing capability

• Announcement support • Account Codes

• Personal Toll Free Service and other pin based services • Off-board Authentication (such as OSP)

For more information, please see details in the Services section of the document.

Policy Element

The Policy element (PE) is a generic policy engine allowing it to be leveraged for service association and network policy administration. At the simplest level this element responds to call related queries with treatments based on a database of provisioned policies. The PE supports a real time in memory hierarchical database to enable call-processing transac-tions to occur at a high rate.

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At the beginning of any call (that is determined to be process-able), the policy element is queried by the SEE for call treatment. Once received by the policy element along with an indication of what policy tables to query, the policy engine queries the appropriate data-base(s) to determine the call handling attributes for associated services and returns those to the SEE. The most base illustration would be for routing - upon receiving a query indi-cating a route request, the PE queries the indicated routing policies and returns the appro-priate routes (or release treatments).

The policy element can support multiple policy queries and executions within the context of a single call enabling multiple trigger driven services. To achieve this, the PE supports user configurable Service Trigger interface. This is modeled in a similar fashion the inter-face used for routing however treatments identify a service to be executed. The Service Trigger Plan Group is modeled after the AIN 0.2 call model and uses standard trigger detection points and trigger types to identify a Point in Call. Multiple Services can be trig-gered for any call.

For more information, please see section “Policy Element - Supported Policies”

Events Collector

The Events Collector (EC) is responsible for collection and storage of billing and call-related events from the various ControlSwitch elements.

The Events Collector receives events associated with a call and its progress through the system. These events are received by the EC from ControlSwitch CCE elements. The EC indexes and stores these events for operational report generation and for use by billing systems.

CDR Element

The Call Detail Record (CDR) element is responsible for the ControlSwitch billing and data analysis functions. The CDR Element handles the billing data formatting and trans-porting functions.

Due to the need to accommodate a wide variety of customer billing applications, the

ControlSwitch billing solution generates a text-based generic Call Detail Record (ICDR)

that can be fed into billing mediation solutions that specialize in supporting custom inter-faces to billing and customer care applications. Furthermore, the ControlSwitch billing solution can also generate billing records according to the Bellcore AMA Format (BAF).

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Element Management System

The Element Management System (EMS) is responsible for provisioning all the compo-nents of a ControlSwitch system. In addition it proactively monitors the status of the system's elements. At the provisioning level, the EMS sets up and initializes all of the components in a ControlSwitch system, including the CCE, SG, PE, EC, and CDR. In addition to setting up individual element, the EMS ensures that all these elements of the system are brought up in the proper sequence, and that the appropriate relationships are enabled among the elements.

The EMS supports multiple aspects of system monitoring, including real-time alarms, call tracing and diagnostics, performance statistics and traffic reports and browsing of Call Detail Records stored in the CDR Manager. The EMS is designed to give the network administrator all the necessary information to properly monitor and operate the system. The EMS also serves an important role in ensuring high availability of ControlSwitch functionality. It performs sanity checks as well as rebinding operations of elements after an element failure is detected and its functional failover to an alternate element has occurred.

The EMS user interface is a Web browser-based GUI. The screens are logically laid out and enable the user to intuitively provision the system. Additionally, event alarms are displayed in near real time on the GUI.

IP Call Element

The IP Call Element (ICE) can be viewed as a sub element (or sister element) to the CCE in that it uses common modules for resource management and functions as the interface for call processing. The ICE however is optimized for management of VoIP based proto-cols (H.323 and SIP) as opposed to resource management protoproto-cols and PSTN protoproto-cols as is the case with the CCE. As with the CCE, the ICE provides protocol processing and resource management functions that allow call legs to be controlled within the system however does not manage the state machines for the calls and services. In short, the ICEs primary responsibilities fall into the following categories;

• Protocol Processing

• Protocol mediation between network facing protocols (MGCP, ISDN, SS-7 etc.) and the internal generic call processing protocol

• Resource Management (TGs, channels, gateways, etc.)

For IP based protocols. The ICE may exist as a standalone element processing only the VoIP leg of calls and interface to the other CCEs/ICEs for the other leg of the call or may be installed on the same platform as CCEs. The decision is a function of network planning. The ICE will support both H.323 and SIP simultaneously and can interface to multiple networks of either type as distinct gateways to each network.

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SS7 Access Server

The SS7 Access Server (SAS) is a logical process that is used to support M3UA in the

ControlSwitch network. Its functional role can be summarized as follows:

• Arbitrate provisioning requests from the EMS • Manage ASP processes

• Implements the ASP redundancy logic • Provides ISUP encode-decode functionality • Report events to the EMS

The SAS creates and manages the M3UA AS/ASP processes and functions in an active/ standby pair. The redundant ASP pair in turn represents a single local point code and manages traffic for multiple routing contexts configured for that local point code. The association between the SAS and the ASPs is many to one, meaning that a single SAS will “parent” ASPs based on the number of local point codes the switch represents. Each SAS has a redundant mate, which in turn has redundant ASPs.

The ASPs associated with a given SAS (or SAS pair) will initiate and terminate the M3UA traffic to and from their mate SGP process (which in turn interfaces to the SS-7 network). The SAS then manages the ASPs as well as the ASP activity (failover etc.).

The SAS can reside on a separate platform from other ControlSwitch elements, or can be combined with a CCE process or processes. When combined with the CCE, there is an inherent performance impact on the platform. Due to the fact that there is no fixed associ-ation between the SAS (and ASP resources) and a given CCE, the performance impact cannot be determined unless explicitly engineered to have a deterministic relationship. Consequently, it is recommended that production applications deploy the SAS element on a separate hardware platform. Currently, the SAS is only supported on a separate hardware platform.

ControlSwitch Element Interactions

To understand the relationship between the various ControlSwitch elements let us

consider the case of a call dialed by a user whose telephone is connected to a local carrier's Class 5 switch located in a CO. For this example let us consider a call dialed to another PSTN-based telephone. Typically, the Class switch to which the caller is connected uses the dialed phone number and the calling subscriber's information to select an outgoing bearer IMT to send the call on to the new generation infrastructure represented by the

ControlSwitch and associated media gateways. The Class switch sends the call-related

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Figure 4-3: ControlSwitch Element Interactions

Upon receiving the call's parameters in an SS7 IAM message, the SG generates a unique call identifier. The SG selects the appropriate CCE (the ingress CCE that manages the media gateway to which the incoming call's bearer IMT is connected) using OPC-DPC-CIC values included in the IAM, and then sends the call parameters to the ingress CCE over the IP network. The ingress CCE now becomes aware of the incoming call and carries out the following tasks:

1. Communicates with an PE to request a route(s) to send the call to its destination 2. Communicates with the ingress media gateway using MGCP/H.248 to request that an

ingress call end-point be established on the media gateway; this end point serves as the end of the first call leg from the calling phone to the ingress media gateway. Upon receiving a route from the PE (a route includes the identity of the egress CCE and the egress trunk group to be used for the call) the ingress CCE passes the call parameters (as well as the unique call identifier) to the egress CCE. The egress CCE then carries out a number of tasks:

3. Selects an available channel on the indicated egress trunk group and requests (via

MGCP/H.248) that the egress media gateway establish an end point for the egress leg of the call to the destination phone

4. Passes the call parameters to an egress SG.

The egress SG uses the SS7 network to instruct the terminating switch to ring the destina-tion telephone.

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With endpoints established at both ingress and egress media gateways, the two CCEs now exchange the RTP port numbers of the endpoints, enabling a VoIP path between the ingress and egress call legs.

The CCEs generate call events during the call setup as well as throughout the entire call. These events are sent to the Event Collector where they are suitably indexed and stored. Stored call events are later used by the CDR Element to generate call detail records. System operational reports such as traffic and network utilization are also generated from these call events. These interactions can be represented in the call flow shown below:

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Scalability for Large Networks

The ControlSwitch's distributed design allows carriers to start with small deployments and scale the system up by the addition of particular elements as traffic-induced loading is experienced by these particular elements or as the number of trunks/ports to be managed is increased. Furthermore, a considerable amount of network design flexibility is permitted by the distributed design.

Depending on the nature of operational methodology and/or facilities distribution, a service provider might choose to locate the EMS, PE, EC and CDRE in a location close to the network operations and IT systems while the call control and signaling elements could be located in various switching centers selected for convenience of the switching plant and related personnel. Media gateways can be added in the various points-of-presence (POPs) depending on the provisioning of trunks to the PSTN and to customer sites. The media gateway control of these media gateways can be assigned to appropriate SG/CCE based on load distribution and signaling link disposition. The only requirement is that between any two elements there is a redundant IP network path of sufficient bandwidth and quality for the operational and real-time interaction of the various ControlSwitch elements to be transported reliably and with low delay.

When more media gateways and/or bearer trunks are added, to the extent that all CCEs are running at full capacity, the service provider can install additional CCEs for handling these added media devices and the related call traffic. The interrelationships of the new elements with previously operational ones are set up from the user-friendly EMS GUI. Similarly, SG elements can be added as the amount of SS7 traffic grows beyond the capacity of already operational SG. The same scaling principle applies for the PE and EC. The modular growth of the ControlSwitch system allows service providers to start out with a modest investment and gradually grow the installed system as traffic demand and revenue opportunities justify further investments

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Chapter 5

Supported Customer

Environments

This chapter describes the various supported customer environments.The following topics are included in this chapter:

• Class 4/5 Switch Interfaces

• PBX and RAS / NAS Device Interfaces • STP Interfaces