Enhanced Services for Converged Networks The Importance of SS7 Internet Telephony Expo February 2003

Leveraging SS7 for IP Telephony Before SS7-IN for IP Voice can be discussed…. What is IP Telephony? Technical Models Business Models Where it is going The Role of SS7 in IP Telephony PSTN Interconnect Service Delivery (Existing) Service Development (New) Leveraging SS7 Do you have a choice? Should you have a choice?

What is IP Telephony/VoIP? Well, it’s Telephony using IP…..(duh)? What is new about it? Well, it uses IP….(duh) IP Telephony can mean many things: Trunking between class 4 switches (arbitrage and intercarrier) Trunking between class 5 switches (tandem apps) Replacing Class 5 switches (access) A new thing? A new form of communication? IP Telephony is really about three things: Redefining Access Redefining Services Integrating Discrete forms of communications (mobile, voice, visual, information, dialogue, broadcast, entertainment)

The Business Drivers for IP Voice Technology is not the driver Subscribers don’t care about protocols, codecs or algorithms. Access Finding new ways to reach the customer Increasing accessibility of services to the customer Mobility of voice Access through multiple devices Bypassing ownership of physical plant Services Enhanced ability to use existing services Web provisioning Voice navigation Always on, always there Cool new services Integrating the four primary communications tools

The Business Drivers for IP Voice New Revenue Technology is not the driver Subscribers don’t care about protocols, codecs or algorithms. Access Finding new ways to reach the customer Increasing accessibility of services to the customer Mobility of voice Access through multiple devices Bypassing ownership of physical plant Services Enhanced ability to use existing services Web provisioning Voice navigation Always on, always there Cool new services Integrating the four primary communications tools Lower Costs

Evolution of IP Voice Current focus is on re-inventing traditional voice services and architectures on an IP backbone Incremental improvements and feature enhancements Integration with PC voice applications like Windows Messenger Web-based provisioning of service Mobility SS7 is the primary mechanism for controlling call states and services Longer-term, the Services Infrastructure will change New features, even for traditional voice, will be developed on IP-based systems New features and services – the “killer apps” IP (presumably SIP but also something else akin to Parlay) will replace SS7 for services and inter-node signaling

SS7 Service Architecture Billing, Provisioning, Customer Service Data Repository Services Layer SCP SCP Signaling Links STP STP Service Node Signaling Layer Service Node STP STP Media Layer SSP SSP Voice Trunks

SS7 Service Architecture Billing, Provisioning, Customer Service Data Repository Services Layer SCP SCP Signaling Links STP STP Service Node Signaling Layer Intelligent Network Centralized core data model for services 0800, LNP, VPN, and mobile only services widely deployed Application and data intertwined, making provisioning and back office difficult and costly Expensive, proprietary platforms Service Node STP STP Media Layer SSP SSP Voice Trunks

SS7 Service Architecture Service Node Most common model for PSTN services Voice mail, calling card, call center Separate provisioning, billing, customer service for each platform Expensive and non-integrated Billing, Provisioning, Customer Service Data Repository Services Layer SCP SCP Signaling Links STP STP Service Node Signaling Layer Service Node STP STP Media Layer SSP SSP Voice Trunks

SS7 Service Architecture Switch Based (CLASS, Centrex) Requires local provisioning on each Class 5 switch No mobility Expensive, time consuming for new feature deployment Billing, Provisioning, Customer Service Data Repository Services Layer SCP SCP Signaling Links STP STP Service Node Signaling Layer Service Node STP STP Media Layer SSP SSP Voice Trunks

Why Migrate Services to IP? Reduce back office costs Vendor End of Life of IN platforms Speed time to market by integrating provisioning systems with Web front end Reduce customer service call center expenses by automating service delivery and turn up through the Web Integrate AAA Internet infrastructure with voice services Provide integrated services for voice and web customers Provide mobility to subscribers Integrate VPN, Work at Home and Mobile service offerings The bottom line: Migration must serve a business purpose and provide new features and end-user benefits. Migration for migration’s sake is a tough case to make

VoIP Service Architecture Application Server Services Layer Core Services Platform Application Server Billing, Provisioning, Customer Service Application Server Signaling Layer Signaling SIP Proxy/GK SG MGC MGC SG Media Layer STP STP STP Media STP MG MG

VoIP Service Architecture Handset Based Services Unlike PSTN, digital signaling right to the handset Could be a soft-phone (e.g. XP Client) Limited to specific local features Application Server Services Layer Core Services Platform Application Server Billing, Provisioning, Customer Service Application Server Signaling Layer Signaling SIP Proxy/GK SG MGC MGC SG Media Layer STP STP STP Media STP MG MG

VoIP Service Architecture Edge Services Softswtiches (MGCs) and proxy servers can operate edge oriented services Potentially difficult to provision and manage as network scales up Service parity and consistency difficult in multi-vendor networks Application Server Services Layer Core Services Platform Application Server Billing, Provisioning, Customer Service Application Server Signaling Layer Signaling SIP Proxy/GK SG MGC MGC SG Media Layer STP STP STP Media STP MG MG

VoIP Service Architecture Application Server Services Layer Core Services Platform Application Server Billing, Provisioning, Customer Service Application Server Core Network Services Contain dial plans, central network routing data Open, standard platforms, databases Application servers can share information, resources Web-based provisioning enables carrier to offer subscribers convenience and self serve customization while maintaining control Signaling Layer Signaling SIP Proxy/GK SG MGC MGC SG Media Layer STP STP STP Media STP MG MG

Services in the Converged Network Initially… Existing infrastructure will be used for existing apps New infrastructure will be used for new apps Moving Forward… Service Mediation role is critical but barely understood SS7 should terminate at the edge of the IP network New enhanced service infrastructure needs to be defined and developed

Leveraging SS7 – Do You Have A Choice? For PSTN interconnect, ISUP is required for even simple voice termination This will not change SS7 interconnect will always be required For Services, there are alternatives Use TCAP-AIN as the universal services protocol across IP Use full AIN from existing infrastructure Use TCAP-AIN for very basic query response to legacy infrastructure Forget it – build a new IN based on DNS/SIP/Protocol X

98% of world’s voice traffic Today’s Networks PSTN: 98% of world’s voice traffic GW/SS VoIP

Wither SS7? Approaches Provide direct TCAP interfaces to the SoftSwitch layer and have SoftSwitch function as full SSP Most direct resemblance to PSTN SoftSwitches are years from having full capability Performance issues Too much to build on a single platform Provide an Service Mediator that maps AIN to IP and holds call state (this is a true SCP implementation) Requires additional node in the network Most scaleable Requires standardization of service delivery profiles in SIP

Enabler: Service Mediation Server To enable migration, a service mediation server must live at the edge of the network Call states and triggers must map to the existing IN platforms, hold state, and delivery transaction based messaging to SoftSwitches Porting SoftSwitch SSP to the edge Transitionary platform? Or permanent?

Converged Network Service Delivery PSTN IP PSTN OAMP SMS App Server Services Layer IP OAMP SMS App Server Service Mediation App Server SCP TCAP/SCTP SS7 SIP, H.323 Signaling Layer SIP Proxy/GK STP Sig GW MGC ISUP/SCTP MGCP, MEGACO Media Layer STP SSP STP MG Media: IMT Media: RTP PSTN IP

SS7 Services for VoIP Networks PSTN IP Services Layer PSTN OAMP SMS App Server IP OAMP SMS App Server Service Mediation App Server SCP TCAP/SCTP SS7 SIP, H.323 Signaling Layer SIP Proxy/GK STP Sig GW MGC ISUP/SCTP PSTN services are defined in SCP, accessed through TCAP/SCTP 0800, LNP, Dialing Plans trigger a query through TCAP/SCTP to SCP IP Application platform retrieves data, translates to SIP, sends to SoftSwitches MGCP, MEGACO Media Layer STP SSP STP MG Media: IMT Media: RTP PSTN IP

VoIP Services for SS7 Networks PSTN IP App Server Services Layer PSTN OAMP SMS IP OAMP SMS App Server Service Mediation App Server SCP TCAP/SCTP SS7 SIP, H.323 Signaling Layer SIP Proxy/GK STP Sig GW MGC ISUP/SCTP IP-based services are defined in Application servers and accessed Using SIP, DNS or Parlay SSP issues TCAP query Service Mediation gateway resolves query and accesses appropriate servers. MGCP, MEGACO Media Layer STP SSP STP MG Media: IMT Media: RTP PSTN IP

Enabler: DNS DNS provides the strongest alternative to TCAP for Query-Response applications Current DNS infrastructure is default address resolver for IP Many IN apps are address resolution: Basic Tandem Routing Carrier Select LNP 800 CNAM Problem: Most IN apps require Call Models when anything advanced is delivered. Very few IN apps are pure query response Call Model Server + DNS

Where We’re Eventually Headed VoIP: 98% of world’s voice traffic GW/SS PSTN

Hybrid Network Service Architecture PSTN Other Servers SCP Service Mediation Service Layer STP/SG STP SIP Call processing Layer SSP MGC SSP PBX IP SCP looks like an SSP to the legacy network Triggers in IP map to SIP

Towards a VoIP Service Logic Real Time Billing Server/OSP Server Service Management System HP Open View Access Network {RADIUS/OSP} H.323 GK H323 GW {XML} {SNMP} Access Network {XML} {SNMP} SCP PBX SIP GW {RADIUS /OSP} IP STP {SIP} {H323} {SIP} {H323} Access Network {SIP or H.323} H323 GW Trunking GW PSTN

Conclusions Models for SS7 in VoIP will depend on the carrier business model, service set, and installed network infrastructure Some SS7 service logic is required for PSTN interconnect Major architectural options: Where to house the triggers Where to terminate SS7 and AIN Service Mediation function Optimal outcomes will leverage existing SS7 investments but not impose TCAP-AIN on IP components Service Core must move to IP, even if the IN services remain on the PSTN

Michael Gaines +1 (613) 592-2100 michael.gaines@ss8.com Thank-you! Michael Gaines +1 (613) 592-2100 michael.gaines@ss8.com