White Paper

The Superclass SoftswitchWhat service providers require from day one to deploy VoIP in their core networks

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IntroductionThe heart and soul of the next-generationnetwork is the softswitch—the software-based switching center for Voice over IP(VoIP) networks. With a more flexible andefficient architecture, the softswitchenables service providers to expand theirservice delivery capabilities and open newrevenue streams. But the benefits don’t endwith top line revenues. By providing theability to lower operational costs, thesoftswitch also effectively addresses theservices provider’s bottom line. In short,the softswitch can assist in reshaping theeconomics and revenue potential of thepublic switched telephone network(PSTN).

As we get deeper into the transition fromcircuit to packet networks, the key roles of the softswitch are now clear. It carefullycoordinates intercommunication amongapplication servers, media gateways, andaudio servers. It provides overall callmanagement, enabling subscribers tocomplete calls and other communications.It allows service providers to deliver serv-ices more flexibly than ever before. And itdoes all this using open, standards-basedprotocols to interoperate seamlessly with‘best-in-class’, next-generation networkelements.

Although the softswitch is the lynchpin ofthe VoIP network, there are many differenttypes on the market today. Softswitchescome in various shapes and sizes, withmany of them targeting niche applicationssuch as PRI offload or toll arbitrage. Thetime has now come to draw the distinctionbetween softswitches that can truly replacethe core of the PSTN network and thosethat fit niche applications on the fringe.

Defining the superclasssoftswitchThis paper focuses on providing a cleardefinition of the attributes of the superclasssoftswitch—a softswitch with all the neces-sary features, capabilities, and supportrequirements for deployment in the coreof a service provider’s network. A super-class softswitch enables complete migra-tion to VoIP.

Nortel Networks is a leader in deployingglobal packet solutions for local, longdistance, and wireless carriers. Our vastcustomer experience in both circuit-switched and packet-based networksaround the world gives us a unique abilityto define and develop this new category ofsoftswitch.

The four core attributes of the superclasssoftswitch that we will discuss in depth are:

• Integrated architecture—The superclasssoftswitch supports multiple core appli-cations on a single platform includinglocal, long distance, and tandem.

• Services—The superclass softswitchdelivers feature transparency andprovides a ‘future-proof ’ platform fornext-generation multimedia services.

• Regulatory requirements—The super-class softswitch complies with existinggovernment regulations.

• Carrier-grade attributes—The super-class softswitch is intended to satisfy theservice provider’s most stringent robust-ness and operational requirements.

Nortel Networks has worked hand-in-hand with leading global voice and dataservice providers that are forging ahead indeploying Voice over IP today. The criteriawe use to define the superclass softswitchderives from a set of rigorous requirementsgathered over many years in working withthese providers. These requirements aredesigned to:

• Enable service providers to transitiontheir existing networks seamlessly topacket-based networks

• Drive incremental revenue opportunities

• Enable service providers to significantlyreduce capital and operational expenses

Integrated architectureMany softswitches deployed today beganby offering an economical way to deliverspecialized applications, such as trunkingfor niche applications (PRI offload, forexample), basic 1+ long distance for tollarbitrage, and calling card services.

A subset of softswitch vendors are begin-ning to offer Class 5 line applications andlifeline services on some softswitches.

Providing leading network and serviceflexibility, a superclass softswitch deliversthe full vertical set of switching and service

Qwest

SBC

Verizon

SBC

BellSouth

Figure 1. Section 271 of Telecommunications Act of 1996 granted in 48 states

delivery applications in one package—including local, tandem, long distance,business Centrex, and residential lineapplications. With a superclass softswitch,service providers can now leverage theirsignificant infrastructure investment (suchas softswitches and media gateways) toaddress multiple segments—includinglocal, tandem, long distance, wirelesstransit, and cable.

An excellent example of the business valueof an integrated architecture is the oppor-tunity that sections 271 and 272 of theTelecommunications Act of 1996 bring.(The Telecom Act of 1996 governs deregu-lation in the US.) On a state-by-statebasis, Bell operating companies (BOCs)were allowed to apply for what is oftenreferred to as 271 relief, allowing them toenter the in-region long distance marketwith some restrictions.

Section 272 spells out how a BOC’s localand long distance lines of business must be structurally separate. This arm’s lengthrelationship between the different marketsegments is aimed at stifling anti-competi-tive practices by service providers such ascross-subsidization or favoring of theirown long distance service. In essence, thissection mandates two completely distinctentities, with separate accounting, officers,directors, employees, and operating infra-structure (such as switching equipmentand networks).

Under the sunset provision of section 272,the separate affiliate requirement ceases toapply three years after a BOC has beenauthorized to provide in-region, inter-LATAtelecommunications services under section271(d). The FCC could also extend thisperiod, but they have not yet done so.

Given that 48 states have already granted271 approval to BOCs and one more ispending, BOCs nationwide may be in the local and long distance business in thevery near term. Moreover, within threeyears, most—if not all—states are expectedto operate without separate affiliate require-ments. Verizon in New York is the first toreach this stage.

The significance of sections 271 and 272is that many North American serviceproviders may be providing local, tandem,and long distance services within anyserving area they choose. This includesBOCs (previously restricted), CLECs,IXCs, and cable MSOs (not currentlyrestricted). All of these service providersmay benefit from leveraging a singleswitching infrastructure—powered by asuperclass softswitch—to deliver services.By doing so, the service provider may gainsignificant operational and capital expensereductions derived from consolidated assetsand simplified operations management.

ServicesAnother critical attribute of the superclasssoftswitch is the ability to provide full-featured service transparency. There areover 3,000 features in use today within theglobal PSTN. These features include:

• Centrex business customer services(200+ services)

• CLASS/Custom Calling residentialservices (300+)

• A long list of tandem, long distance, andoperational features, including alarms,logs, performance metrics, security,billing, regulatory, operator and direc-tory services, and international signalingvariants

See Appendices A and B for sample lists.

Some service providers simply do not want to alter their service offerings totheir customer base. They have no wish tonotify a customer that a set of features theyhave subscribed to and relied on for years isbeing eliminated or changed due to a tech-nology “upgrade” in the network core.

There is good reason for this. The servicesrevenue stream from subscribers is rela-tively constant and predictable—as long asservice providers do not change the terms.Reducing or changing the service offeringopens the door to negotiating the serviceat a lower price. Worse yet, the subscribercould solicit alternative offers, since achange is occurring anyway.

The feature transparency delivered by asuperclass softswitch allows the serviceprovider to migrate their customers seam-lessly to a next-generation architecturewithout the need to negotiate on thedelivery of current services. Instead, serviceproviders can focus on up-selling newmultimedia services as a value add-on totheir current service bundles. This strategymay increase current revenues instead ofputting existing revenue at risk.

Addressing the service provider’s installedbase with feature transparency is a hugeadvantage in transitioning the network.But now let’s take a look at how it canaffect market growth. How does the richlyexpanded service set help increase revenueopportunities?

Outside Territory Outside TerritoryACME Telco Territory

Customer XBranch

Customer XHeadquarters

SuperclassSoftswitch

Customer XBranch

Next targetcustomer

Figure 2. Out-of-territory example—Voice over IP VPN

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Clearly, one way to increase the size of the‘pie’ in today’s difficult market is to increasethe service provider’s addressable market.The superclass softswitch can assist serviceproviders in doing this by combining acomplete, centrally located feature set withthe distributed network advantages of aVoIP architecture.

By deploying cost-effective media gatewaysfor out-of-territory deployment, serviceproviders have the opportunity to attractnew customers in another provider’s tradi-tional territory. This can be especiallyeffective when you have a campuscustomer with satellites in other regionsthat you do not currently serve. By lever-aging your strong relationship with yourcustomer’s headquarters, the superclasssoftswitch enables you to gain access tobranch offices nationwide under thecontrol of a single softswitch.

An example service that addresses out-of-territory expansion is the Voice over IP(VoIP) Virtual Private Network (VPN)application. This service enables providersto offer a private dial plan for customersusing any service access architecture—including Centrex, Centrex IP, PBX, andIP PBX. Support for H.323 enables inte-grated access of voice, video, and data aswell as cost-effective out-of-territory reachto pick up branch offices.

Regulatory requirementsIn today’s telecom environment, the finalhurdle to clear in migrating from circuit to packet is often softswitch support forregulatory requirements.

Governments around the world areconcerned with functionality that addressesthe needs of public safety as well aspromoting fair competition. A superclasssoftswitch must support the broad set ofservices available in today’s network toenable lawful intercept, number portabil-ity, emergency, and operator services.

Superclass softswitches benefit fromhaving an architectural framework thatmakes it easier to deliver these services andadapt to the needs of new countries andterritories requiring softswitches in theirnetworks.

From a public safety perspective, asuperclass softswitch must support three key areas:

• Law enforcement—includinginvestigative and reporting

• Emergency call handling

• Service availability—lifeline service

Lawful interceptIn times when we are all acutely aware of the need for national security, lawfulintercept—the ability of law enforcementagencies to monitor private communi-cations—is key.

In the U.S., CALEA (the Communica-tions Assistance for Law Enforcement Act)defines the standard for lawful intercept.Outside the U.S., the generic term lawfulintercept is often used. Lawful interceptmust be implemented in the superclasssoftswitch so that new countries can easilyextend this capability to meet strict regula-tory requirements and ensure undetectedlawful monitoring by enforcement agencies.

Government EmergencyTelecommunications Service (GETS)Also related to national security, theGovernment Emergency Telecommunica-tions Service (GETS) was implemented in the 1990s. GETS enables emergencyofficials to make maximum use of allavailable telephone resources in the eventof congestion or outages caused by emer-gency, crisis, or war.

GETS provides access authorization, prior-ity treatment, and enhanced routing forgovernment agencies and officials using acalling card and a pin code mechanism.This is a common feature today in the

PSTN, especially in highly populated areasand areas with large concentrations ofgovernment offices.

On September 11, 2001, there were morethan 18,000 GETS calls worldwide, with acompletion rate of 95 percent.1 GETS wasalso used during the Nisqually Earthquakeand Hurricane Opal. In such times ofcrisis, there is often no other way to getcommunications through for the NationalSecurity/Emergency Preparedness (NS/EP)community. As service providers migratetheir network cores to packet, GETSsupport in a superclass softswitch will be more critical.

E911Emergency services such as E911 supportthe public safety mandate by enablinglocation identification, reporting, anddispatch support. This capability has beenproven over a period of years in the publicnetwork for traditional lines and standardsare being developed for nomadic IP-basedlines.

The challenge is to offer these same capa-bilities in the softswitch, so that serviceproviders can avoid any impact to service.A commonly used example service is Anti-Disconnect (or Call Back), which preventsa caller from disconnecting an emergencyservice call. This service ensures that anaccidental hang-up does not happen andthat a dispatcher does not lose the criticalinformation needed to send appropriateand timely support.

Operator servicesEvery U.S. LATA (Local Access andTransport Area) requires a tandem switchwith operator services. A number of serv-ices are included under the banner ofoperator services, including directory assis-tance, call placement, busy line verification,and interruption. The operator servicesuite includes capabilities that span Class 4and 5 switches.

41 GETS FAQ on ncs.gov Web site.

Let’s look at an example of a critical opera-tor service. A subscriber may need to reachhis or her child in an emergency, but theline is busy for over an hour. An operatorat the Class 4 tandem verifies that the lineon the Class 5 system is actually busy andnot off-hook. The operator then interruptsthe call in progress to get the messagethrough.

This service requires seamless interoperabil-ity between multiple systems and poten-tially between different technologies—thatis, the circuit-switched and packet-basednetwork. The superclass softswitch mustsupport these capabilities and interoperatewith existing Class 4 and 5 systems—whether circuit- or packet-based.

Number portabilityRegulatory issues are not restricted topublic safety. Another area of focus ispromoting fair competition in the market-place. The Telecom Act of 1996 mandatesthat residential and business subscriberswho are not changing their location must

be allowed to retain their existing directorynumbers when changing from one serviceprovider to another. In addition to theU.S., this requirement also exists in manyderegulated global telephone networksaround the world. It will also be requiredin U.S. wireless networks in November2003 barring a deadline extension.

The number portability feature set meetsthis requirement. A number of technicaloptions exist to satisfy this requirementand a superclass softswitch should addressseveral of them. This includes All CallQuery (N-1 switch) in the U.S., as well asIN-based solution with off-board SCP andSignal Relay Function (SRF) for wirelessin Europe.

Number portability causes some otherproblems in operating an efficient publicnetwork. These problems include allocat-ing NPA-NXXs in blocks of 10,000,which is wasteful. Number pooling is animplementation option that reduces thesize of blocks to 1,000, and thus conservesthe numbering plan.

Features inspired by regulatory require-ments are crucial for serving public safetyand leveling the playing field for acompetitive telecommunications market.Service providers who are serious aboutcircuit-to-packet migration in the core oftheir network must consider the breadthof regulatory support in the softswitchesthey evaluate.

Carrier-grade attributesFinally, a superclass softswitch must enableservice providers to migrate easily fromcircuit-switched to packet-based technol-ogy with minimal or no impact. To dothis, it must offer:

• Uptime and robustness

• Ease of network growth

• Seamless integration with third-partyproducts

Robustness definedThe North American public network has a long legacy of leadership in performanceand reliability. Our critical emergency,

5

PBX

International

FaxDiplomatic

TelecommunicationsService (DTS)

Cellular/PCSPSTN with

access authorization,enhanced routing, and

priority treatment

InternationalMaritime Satellite

(INMARSAT)

Mobile SatelliteSystem (MSS)

Defense InformationSystem Network

(DISN)

FederalTelecommunications

System 2001 (FTS2001)

Figure 3. GETS Operational Concept

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government, and financial services rely ona dependable communications network.And, the same is true of the telecommuni-cations requirements for daily commerceand for keeping in touch with family andfriends.

Five-nines (99.999 percent) availability has been the gold standard for measuringuptime requirements in the public network.This number is not simply a benchmarkfor designing equipment and networks. It is used to measure and report annuallyby the United States Federal Communica-tions Commission (FCC).

The U.S. FCC Automated ReportingManagement Information System(ARMIS) tracks operational, financial,service quality, and infrastructure informa-tion for most of the larger local exchangecarriers (LECs) in the US. Specifically, theService Quality Report (FCC ARMISReport 43-05)2 documents uptime andoutage statistics.

Vendors with a history of deploying highlyrobust software and hardware (as docu-mented in this report) are well positionedto deploy a superclass softswitch withsimilar robustness characteristics. Theskills that a vendor gains from developingand testing carrier-grade software areequally applicable in both circuit-switchedand packet-based environments.

The platinum standard for softswitchesA softswitch is not carrier-grade simplybecause it is deployed on a commercialserver hardware platform with 99.999percent availability. The standard require-ment is five-nines availability across thenetwork, end-to-end—not simply insoftswitch hardware performance. The aggregation of all the hardwarecomponents must be considered whenassessing availability of the network. This includes softswitches and media

gateways, with associated software for each component.

A superclass softswitch must also incor-porate the fault-tolerant software andredundant hardware that is required totransparently perform fault handling, thusassuring the highest degree of availability.As the central point of control within aVoIP network, the softswitch standard forrobustness must be the very highest. Aplatinum, rather than gold, standard ispreferred to enable five-nines availabilityfor the end-to-end network.

Softswitch platform optionsThe architecture of the softswitch platformdirectly affects system availability. Thereare two primary hardware architecturesemployed—the commercial server and the blade-based chassis.

Commercial servers

Server-based systems typically usecommercial, NEBS-compliant, carrier-grade server platforms. Server-based plat-form benefits include pre-testing forproduct integrity and the use of commer-cially available technology (which leveragesservice provider information technologyexperience). These are significant benefitsfor applications such as OAM&P manage-ment platforms.

However, for softswitches, there are somelimitations to using commercial servers.Scalability often requires additional physi-cal servers, which take up space and thusadd to operational costs. In addition,servers are often deployed in a load-sharing arrangement where the engineeredload requires all servers to be active. If apeak network condition occurs and aserver becomes unavailable, the overallnetwork capacity can be significantlyreduced at a critical time.

Another issue is convenience. Adding anincremental component such as an SS7

signaling gateway requires a separatephysical hardware platform that may ormay not co-reside in the same frame as the servers.

Blade-based platforms

Blade-based platforms allow serviceproviders to install off-the-shelf commer-cial processor blades within a commonphysical chassis. By merely adding a bladeto the chassis, you can achieve scalabilitythat will accommodate network growthand result in an overall reduction in foot-print. By deploying the blades in pairs(using active and standby processors), theengineered network capacity is unaffectedby outages with individual componentswithin a mated set of processors.

From an operational cost savings perspec-tive, specialized third-party hardware (suchas SS7 signaling gateways) provides theability to integrate seamlessly with littleimpact to footprint. To gain operationalsavings and flexibility, even the computingserver market has moved toward inte-grated, blade-based applications for datacenters.

RedundancyGeographic redundancy is yet another keycomponent of robustness in a superclasssoftswitch. This is especially true as thescale approaches hundreds of thousands of ports. The softswitch must continuefunctioning at full capacity when a singlecentral office is isolated and renderedunavailable. In the event of a terroristattack or natural disaster, the importanceof individual, business, and governmentcommunications becomes more critical,since the chance of damage to thecommunications infrastructure increases.

A solution to this problem is to deployfully redundant softswitch components in geographically dispersed locations for a single softswitch. When a superclasssoftswitch supports true, end-to-end,

2 ARMIS database on fcc.gov Web site

five-nines availability in a geographicallyredundant architecture, the result is a highdegree of robustness and network avail-ability. This platinum level availability is necessary when the service providerintends to migrate the core of theirnetwork to packet.

Third-party interoperabilityThe foundation of next-generation VoIPnetworks is the ability to interoperate inbest-in-class, multi-vendor networks. Thisis true whether the focus is on media gate-ways, application servers, or back officeOperations Support Systems (OSSs).Service providers should be passionateabout embracing open standards as theydeploy a superclass softswitch.

Since there are numerous applications andproducts within VoIP networks, it is notsurprising that there are a number ofdifferent protocols. However, to providethe broadest support for multi-vendorinteroperability, a superclass softswitchmust support the most common callsignaling protocols. These include H.248,MGCP, PacketCable NCS, H.323, andSIP. H.248 and MGCP are commonprotocols for controlling both line andtrunk gateways. PacketCable NCS is

exclusively used in the cable segment forcontrolling line gateways.

Enterprise customers have used H.323 forquite a while for VoIP and for softswitchintercommunication with H.323-enabledIP-PBXs (an important capability). SessionInitiation Protocol is another broadlysupported VoIP-oriented protocol. It isused in a number of applications, includ-ing VoIP clients, application server inter-working, and virtual trunking withenterprise IP-PBXs.

Note that supporting the protocols is only the first step towards multi-vendorinteroperability. Many of the protocolscontinue to evolve, thus interoperabilitypartner programs are crucial for establish-ing successful multi-vendor networks. Arobust interoperability testing programoffers service providers choice and flexibil-ity in their deployments.

Softswitch interoperability with otherelements of the VoIP network is critical,but so is interoperability with back-officeOSSs for fault, configuration, accounting,performance, and security (FCAPS). A number of traditional interfaces exist—such as AMA, CDR, LDAP, PAM, SCC2,and NTSTD—as well as CSV-based data

formats. If the superclass softswitch isdesigned from the ground up to supportthese protocols, the cost and complexity of integrating into back-office OSSs isreduced.

In addition, a number of next-generationprotocols (including data-oriented proto-cols) are being used in greenfield (newnetwork) back-office OSS implementa-tions—including IPDR, XML, SNMP,and Syslog. An integrated elementmanager that centralizes viewing andnorthbound interfaces to back-officesystems is the best way to manage thesuperclass softswitch in a VoIP network.This type of manager reduces the cost andtime required to integrate into the backoffice by aggregating and standardizing the protocols in use.

Support for third-party interoperability,using open-standard protocols, enablesservice providers to deliver best-in-class,end-to-end solutions while:

• Reducing system integration costs

• Delivering a differentiated service set

• Providing seamless back-office interfaces

ConclusionWe have defined the superclass softswitch as a softswitch with the rich capabilitiesrequired by service providers to evolve theheart of their core networks to Voice over IP.

As the telecommunications environmentcontinues to change, service providers aretrying to keep up by deploying packetnetworks with the new services and appli-cations that IP and the Internet promise.The ideal lynchpin in this transition is thesuperclass softswitch, which incorporatesboth the stringent performance standardsof the past and the flexible, innovativeservices of the future.

To provide a smooth transition withoutstranding existing customers, the super-class softswitch must:

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Security

Fault and Performance

Presentation and Configuration

SoftswitchManagement

TrunkGateway

Management

LineGateway

Management

SignalingManagment

MediaServices

Management

PacketCore

Management

BillingManagement

Integrated Element Manager

Configuration

Fault

Accounting Performance

Security

OSS Layer

StandardizedNorth-bound

protocols

SCC2 orNTSTD orSNMP orSYSLOG

AMA orCDR orXML (IPDR) CSV or

XML

PAM orLDAP

Figure 4. Consolidating user interface, OSS feeds, and platforms

Appendix AClass 5 features supported• 18-Button Add-On for Meridian M5000 Series

• 22-Key Add-On for Aries

• Access to Messaging

• Access to Messaging Deny

• Additional Call Offering Unrestricted

• Advanced Intelligent Network

• Advanced Intelligent Network DN

• AFC – Additional Functional Calls

• Agent Status Lamp

• AIN Message Waiting

• Alternate Service Provider

• Analog Display Services Interfaces

• Anonymous Caller Rejection

• Answer Agent Key

• Answer Emergency Key

• Automatic Answer Back

• Automatic Call Back

• Automatic Call Distribution

• Automatic Call Distribution Not Ready

• Automatic Dial

• Automatic Display

• Automatic Line

• Automatic Message Accounting Test CallCapability

• Automatic Recall

• Automatic Recall Dialable Directory Number

• Automatic Time and Charges

• Bearer Capability

• Bridged Night Number

• Bulk Calling Line Identification

• Busy Lamp Field for Meridian Business Sets

• Call Agent

• Call Busy Intragroup or Channel Bus Interface

• Call Forward Fraud Prevention Override

• Call Forward Indication

• Call Forward Timed for CFB

• Call Forward Timed for CFD

• Call Forwarding

• Call Forwarding Busy

• Call Forwarding Busy Internal Calls Only

• Call Forwarding Busy Line

• Call Forwarding Busy Unrestricted

• Call Forwarding Do Not Answer (BusinessSets)

• Call Forwarding Do Not Answer (RES)

• Call Forwarding Do Not Answer for HuntGroup

• Call Forwarding Do Not Answer Unrestricted

• Call Forwarding Do Not Answer VariableTimer

• Call Forwarding Fixed

• Call Forwarding Group Do Not Answer

• Call Forwarding Intragroup

• Call Forwarding MADN Secondary Member

• Call Forwarding on a Per Key Basis

• Call Forwarding Remote Access

• Call Forwarding Simultaneous/Screening

• Call Forwarding Universal

• Call Forwarding Usage Sensitive Denial

• Call Hold

• Call Logging

• Call Management Group

• Call Park

• Call Pickup

• Call Redirect

• Call Screening, Monitoring, and Intercept

• Call Supervisor

• Call Transfer

• Call Transfer Warning

• Call Waiting

• Call Waiting Conference

• Call Waiting Exempt

• Call Waiting Intragroup

• Call Waiting Originating

• Call Waiting Ringback

• Calling Identity Delivery and SuppressionDelivery

• Calling Identity Delivery and Suppression

• Calling Line Identification

• Calling Line Identification with Flash

• Calling Name Delivery

• Calling Name Delivery Blocking

• Calling Number Delivery

• Calling Number Delivery Blocking

• Calling Party Identification

• Cancel Call Waiting

• Carrier Toll Denied

• Circular Hunt

• Common Control Switching Arrangement

• Conference Join

• Control Multiple Call Forwarding

• Controlled Interflow

• Convert

• Customer Data Change

• Customer Originated Trace

• Customer Originated Trace with AMA

• Cutoff on Disconnect

• Denied Call Forwarding

• Denied Incoming Calls

• Denied Origination

• Denied Termination

• Deny Access to CLASS Features

• Deny Call Redirect

• Deny Call Waiting

• Deny Call Waiting Conference

• Deny CSMI

• Deliver integrated local, long distance,and tandem applications, with legacyservice capability

• Meet the regulatory requirements forcritical lifeline services using carrier-grade standards

• Deliver feature transparency and next-generation multimedia services

The purpose of this white paper was toprovide an overview of the genericrequirements of a superclass softswitch. In closing, we would like to refer to thesoftswitch series from Nortel Networks—the Succession Communication Server2000 and Succession CommunicationServer 2000 – Compact. Both of thesesoftswitches were designed from theirinception to incorporate the superclasscapabilities described in this paper.

It is not surprising that the SuccessionCommunication Server 2000 series wasrecognized in the first half of 2003 bySynergy Research as #1 in WorldwideSoftswitch3 market share. Nor is it surpris-ing that the Succession CommunicationServer 2000 series has been deployedglobally since 1999 in the world-classnetworks of many leading serviceproviders. Our list of customers includesBell Canada, Cable & Wireless, CharterCommunications, China Netcom, ChinaTelecom, China Railcom, Connex, Cox,GVT, Hong Kong Broadband Networks,ish, KabelBW, MCI, New World Tel,Optus, Sasktel, Sprint, Telstra, Telus,Tiscali, TeleCable, Verizon, and Vodafone.

Such global market acceptance and meas-ured softswitch leadership demonstratesthat the superclass softswitch attributes of the Succession Communication Server2000 series are clearly valued as serviceproviders make the transition from circuit to packet.

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3 Synergy Research, 1Q03 and 2Q03 CarrierPacket Voice Worldwide, May and August 2003.

• Deny In-Session Activation

• Deny Suppressed Ringing Access

• Deny Three-Way Calling—Usage Sensitive

• Dial Call Waiting

• Dialable Directory Number

• Dialed Number Identification Delivery

• Digitone

• Directed Call Park

• Directed Call Pickup

• Directed Call Pickup Barge-In

• Directed Call Pickup Barge-In Exempt

• Directed Call Pickup Exempt

• Directory Number Hunt

• Display

• Display Agent Status

• Display Option for Aries

• Display Queue Status

• Display Queue Threshold

• Distinctive Ringing

• Distinctive Ringing/Call Waiting

• Distributed Line Hunt

• Do Not Disturb

• Downloadable softkeys for ADSL set

• EKTS Hold

• Emergency Key

• Essential Line

• Exclude External Calls from Call Forwarding

• Exclude Intragroup Calls from Call Forwarding

• Executive Busy Override

• Executive Busy Override Exempt

• Executive Message Waiting

• Extension Bridging

• Extension/Add-On

• Fast Transfer

• FAX-Thru Service

• Feature Group

• Feature Group A

• Feature Keys

• Flash Ignore

• Forced Agent Availability

• Free Number Terminating

• Full Carrier Toll Deny for InternationalCarriers

• Ground Start

• Group Intercom

• Group Intercom All Calls

• Hotel/Motel

• In Call Service Deactivation

• Inhibit Line Busy

• Inhibit Ring Reminder

• In-Session Activation

• In-Session Activation Deactivation

• Inspect Key

• Intercom (Business Sets)

• Intercom (Single-Party Revertive Calling)

• Inter-LATA Full Carrier Toll Denied

• Internal/External Call Forwarding Busy

• Internal/External Call Forwarding Do NotAnswer

• International Primary Carrier

• Intra-LATA Full Carrier Toll Denied

• Intra-LATA PIC

• Key Set Music on Hold

• Key Short Hunt

• Last Number Redial

• Last Number Redial Associated with Set

• Leave Message

• Line Music on Hold

• Line of Business

• Line Overflow to DN

• Line Overflow to Route

• Line Study

• Local Call Detail Recording

• Local Number Portability Test

• Local Service Provider Account Owner

• Local Service Provider Switch Owner

• Long Distance Signal Activate

• Long Distance Signal Option

• Long Distance Signal Ring

• Long Distance Signal Tone

• M536 36-Button Add-On for Meridian M5000Series

• MADN (Multiple Appearance DirectoryNumber)

• MADN Ring Forwarding Manual

• Make Set Busy

• Make Set Busy Intragroup

• Malicious Call Hold

• MDN Lamp

• MDN Member Display

• MDN Member Name

• MDN Release

• MDN Ring Forwarding

• Meridian Business Set Station Camp-On

• Message Deactivation

• Message Waiting

• Message Waiting Indication

• Message Waiting Query

• Multi-Line Hunt

• Multi-Party Bridging

• Name Display

• Night Service

• No Cancel Call Waiting Without Call Waiting

• No Deny

• No Receiver Off-Hook Tone

• Observe Agent

• Operator Number Identification

• Originating Line Select

• Overflow Register (Software)

• Override Call Forward on Account Codes

• Permanent Hold

• Pilot DN Billing

• Plug-Up (Trouble Intercept)

• PORT

• Power Features

• Preferential Hunting

• Prevent Delete Option

• Primary Inter-LATA Carrier

• Privacy Change Allowed CIDS

• Privacy for MADN

• Privacy Release

• Private Business Line

• PVN Priority Line

• Query Busy Station

• Query Time and Date

• Quick Conference Key

• Rate Area

• Reason Display

• Received Digits Billing

• Remote Message Indicator

• Repeated Alert

• Requested Suspension

• Residential Call Hold

• Restricted Sent Paid

• Ring Again

• SCWID with Disposition

• Secondary Directory Number

• Secondary Language

• Security

• Selective Call Acceptance

• Selective Call Forwarding

• Selective Call Rejection

• Series Completion

• Service Group

• Set Based Lamp Field

• Set Model

• Short Timed Release Disconnect

• Simplified Message Desk Interface

• Simultaneous Ringing

• Single-Line Queuing

• Single-Line Variety Package

• SMDI-SMDI Calling Number Delivery

• Special Billing

• Special Delivery Service

• Special Delivery Service Deny

• Speed Calling Long

• Speed Calling Long List L30

• Speed Calling Long List L50

• Speed Calling Short

• Speed Calling Short List

9

10

• Speed Calling User

• Spontaneous Call Waiting ID

• Station Controlled Conference

• Station Message Detail Recording

• Station Origination Restriction

• Station Origination Restrictions Controller

• Station Specific Authorization Codes

• Subscriber Activated Call Blocking

• Subscriber Line Usage

• Subscriber Programmable Ringing

• Supervisor

• Suppress Line Identification Information

• Suppressed Ringing Access

• Suspended Service

• Talking Call Waiting

• Terminating Billing Option

• Terminating DN Billing

• Terminating Fault Option

• Terminating Line Select

• Terminator Billing Option on Hunt Group

• Three-Way Calling

• Three-Way Calling Public Announcement

• Toll Denial

• Toll Essential

• Translations Plan

• Uniform Call Distribution

• Uniform Call Distribution Logged InIndication

• Uniform Call Distribution Login

• Voice Mail Easy Access Deny

• Voice Mail Easy Access Directory Number

• Wake-up Call Ring Timeout

• Wake-Up Call

• Warm Line

• Who’s Calling

Class 4 features supported• 900 Services

• Account Codes

• ANI Screening

• Audio Text

• Call Detail Recording

• Call Prompter

• Calling Card Services

• Debit Card Acceptance

• Dialable Wideband Service

• End-User Man-Machine Interface

• Follow-Me Services

• Fraud Control Features

• Global Virtual Private Networks

• Hotline Services

• Networked Automated Call Distribution

• Networked Centrex

• Operator Access

• Personal Identification Codes

• Speed Dialing Plans

• Telecommuting Services

• Toll-free Services

• Travel Card Services

• Voice Print Services

• Voice Recognition

• Voice Response

• Dialing Plan Features

– 30 Digit– International– Voice VPNs

>Private Dial Plan>Closed User Groups>Off-net>On-net>Forced On-net>Dedicated Access>Registered Site Access>Remote Access

– Flexible Translations– Call Screening– Least Cost Routing– Time of Day Routing– Proportional Routing– Overflow Routing

• Tandem Features– 8xx via TCAP– LNP via TCAP– Multistage Dialing– Direct Access Line– 0+/0–– Feature Group D– E911– X11

Appendix BSignaling variants supported• ETSI ISUP v1

• ETSI ISUP v2

• ANSI ISUP

• ANSI UCP ISUP

• IBN7 (ANSI+)

• UK NUP (BTUP, UK TUP)

• UK ISUP (on ETSI v1)

• SSUTR2 (French TUP)

• SPIROU (French ISUP)

• Spanish ISUP (on ETSI v1)

• Aus Interconnect ISUP

• Aus Inter. ISUP (G.500)

• Aus ISUP (CA 30)

• German ISUP (on ETSI v2)

• Israeli ISUP (on ETSI v2)

• Portuguese ISUP (on ETSI v1)

• Brazilian ISUP (on ETSI v1)

• Czech ISUP (on ETSI v1)

• Mexican ISUP & Mexican (Telmex) ISUP

• Chinese ISUP

• Turkish ISUP

• Italian ISUP

• Spanish v2 ISUP

• Argentinean ISUP

• Malaysian (APC Version) ISUP

• NTNA PRI

• NI-2 PRI

• AT&T (U449/4ESS, N449/4ESS, U459/5ESS)

• ETSI PRI

• French PRI (VN4)

• Spanish PRI (Network side)

• VN4 (France) PRI

• VN6 (France) PRI

• Italian PRI

• Belgium PRI

• Netherlands PRI

• Swiss PRI

11

GlossaryATM Asynchronous Transfer Mode

CableLabs CableLabs is funded by the largest cable operators (Multi-System Operators or MSOs) to develop hybrid fiber/coax(HFC)-based standards and to certify vendor products asmeeting the standards to ensure vendor interoperability.

CAP Competitive Access Provider

CLEC Competitive Local Exchange Carrier

CS Communication server (also referred to as a softswitch, call server, or call management server (CMS)

FCAPS Fault, Configuration, Accounting, Performance, andSecurity for network management

H.248 Also referred to as Megaco, a joint ITU and IETF standardfor media gateway call control.

H.323 H.323 was the first prevalent standard for carrying voiceand video over the Internet. It is actually an umbrella stan-dard encompassing audio coding (G.711, G.723, G.729)and video coding (H.261, H.263) over RTP/UDP, as well as call control (H.225, H.245) over IP. H.323 defines anarchitecture consisting of terminals, gateways, gatekeepers,and multipoint control units.

IXC Interexchange Carrier

ILEC Incumbent Local Exchange Carrier

IP Internet Protocol

ISDN Integrated Service Digital Network

LATA Local Access and Transport Area

MG Media Gateway—the bridge between an IP-based networkand traditional trunk or line interfaces.

MGCP Media Gateway Control Protocol—a predecessor ofH.248/Megaco that is commonly used for controlling lineor trunk media gateways by a softswitch.

NCS Network-based Call Signaling—a line gateway (MultimediaTerminal Adapter or MTA) control protocol exclusive tocable VoIP telephony. Similar to the MGCP protocol.

OAM Operation, Administration, and Maintenance service

OAMP Operation, Administration, Maintenance, and Provisioning service

OSS Operations Support System

PacketCable The PacketCable architecture is aimed at defining interfacespecifications that can be used to develop interoperableequipment capable of providing packet-based voice, video,and other high-speed multimedia services over hybridfiber/coax (HFC) cable systems.

PVC Permanent Virtual Circuit—the class of permanentconnection types provisioned through operator commandsin advance of connection being established (primarily ATM PVC).

Service A carrier that provides services. This includes ILECs,provider CLECs, IXCs, and other types of providers.

SIP Session Initiation Protocol—SIP has a couple of roles in thenetwork. In the most typical sense, it has the role of settingup a session with an end user/SIP client. It is also the proto-col of choice in setting up sessions between elements such as multimedia servers and other servers within the network. It delivers both network services and services at the edge.

SNMP Simple Network Management Protocol—the SNMP is aprotocol for Internet network management services.

SPVC Soft PVC (see PVC)—a virtual connection in which perma-nent connections originate and terminate at the user inter-faces, but are established via signaling within the network.Advantages of SPVCs include reduced operations effort insetting up hop-by-hop PVCs through network, takingadvantage of dynamic routing, and the ability to re-routeconnections upon link or switch failures.

SVC Switched Virtual Circuit—the class of connection typescreated dynamically through network signaling and existonly for the duration of the data transfer. (Includes ATMSVC, SPVC, Frame Relay PVC, IP, and others.)

Succession Nortel Networks end-to-end portfolio of Voice over IPproducts and solutions.

TMN Telecommunications Management Network—developed by ITU as an infrastructure to support management anddeployment of dynamic telecommunications services. It provides a framework for achieving interconnectivity and communication across heterogeneous operating systemsand telecommunications networks.

UAS Universal Audio Server—provides announcements,conferencing, and lawful intercept service.

USP Universal Signaling Point—Nortel Networks SS7 signalinggateway and Signaling Transfer Point (STP).

VC Virtual Circuit

VP Virtual Path

Nortel Networks is an industry leader and innovator focused on transforming how the world

communicates and exchanges information. The company is supplying its service provider and

enterprise customers with communications technology and infrastructure to enable value-added

IP data, voice and multimedia services spanning Wireline Networks, Wireless Networks, Enterprise

Networks, and Optical Networks. As a global company, Nortel Networks does business in more than

150 countries. More information about Nortel Networks can be found on the Web at:

www.nortelnetworks.comFor more information, contact your Nortel Networks representative, or call 1-800-4 NORTEL or 1-800-466-7835 from anywhere in North America.

*Nortel Networks, the Nortel Networks logo, the globemark design, and Succession are trademarks of Nortel Networks. All other trademarks are the property of their owners

Copyright © 2003 Nortel Networks. All rights reserved. Information in this document is subject to change without notice.Nortel Networks assumes no responsibility for any errors that may appear in this document.

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