1. 1 Leveraging SS7 to Deliver IP Services Carl Bergstrom Director – IN & IP Services VeriSign Telecommunication Services Internet Telephony Conference, February 6, 2003

2. 2  VoIP’s most significant impact is from the separation of session (call control) knowledge from the Network Elements involved in call transport. –Unbundled transport and application layers –Services reside outside of switches –Commodity components –“Infinite” scalability Where does the Intelligence go: the Network or the Edge? VoIP’s Impact

3. 3 Service Innovation Connection Plane Connection Negotiation Transcoding Bearer Switching Media Control: SIP, H.323, PNNI, etc. Call Control Plane Signaling and Call Control Service Access Function Switch-Based Service Logic End to End Voice Services Definition Conversion Simulator Configuration Analyzer Services Plane IN Service Logic AAA, Address Resolution Service Logic Service Logic Call Logic Switching Logic Switching Logic OSS Billing Net. Mgt. Fault Mgt Service Provisioning Cust. Provisioning Open Telephony Architecture Open Telephony Architecture Interworking Tool Set

4. 4 The Value of SS7  SS7 is still a significant component of telecom networks –The U.S. SS7 network handles about 15 billion ISDN User Part (ISUP) messages a day –About 2B TCAP queries transverse SS7 databases each day  Circuit switches are not going away anytime soon –Pure softswitch networks have been slow to evolve –Carriers want solutions that leverage existing investments –Access side of the network will remain PSTN until significant issues are resolved:  Emergency services  Reliability  Feature transparency  Calea, LNP, other regulatory issues The SS7 network is the largest transaction network in the world.

5. 5 Phases of Network Evolution  Phase 1: Transport Cost Optimization  Phase 2: New Revenue Generation  Phase 3: Converged Multi-Service Access Networks

6. 6 Phases of Network Evolution Phase 1: Transport cost optimization –Data Offload –Tandem Offload –Wireless Tandem –Leveraging AIN services –Converged Transport –Co-existence of TDM and IP networks PSTN (Wireline/ Wireless) SS7/ HLR Packet Backbone Softswitch/ Signaling Gateway PBX Enterprise ISUP/TCAP/ MAP ISP Gateway/ RAS Gateway/ RAS

7. 7 Transport Cost Optimization: Data Offload  Significant cost savings for dial-up sessions –Use of Inter-machine Trunks (IMT) instead of Primary Rate Interface (PRI) connections can realize average savings of 50% –Relieve switch congestion and reduce need to add switch port capacity  Softswitch provides SS7 call set-up and SS7 to IP conversion

8. 8 SS7 Eliminates Network Congestion Softswitch POTS or ISDN Access Lines Interoffice Trunks Data Trunks Internet Service Provider Tandem Switch Network  1998, Cisco Systems SSP STP SSP

9. 9 IMT/ PRI PSTN SS7 IP/ATM Network MGCP IMT/ PRI Media Gateway / RAS PSTN SS7 MGCP Media Gateway PRI RTP VoIP Enterprise PBX SCP TCAP/SIP PSTN Transport Cost Optimization: Tandem Offload Required routing functionality –Custom dialing and routing plans –LNP support –Toll-free (8xx) routing –Voice VPN support –Local, intra-LATA and inter- LATA call routing –International call routing –Feature Group D services – carrier selection –Operator & directory assistance –Least cost routing Softswitch/ Signaling Gateway

10. 10 Co-existent Networks / Leveraging AIN Services IP Network Gatekeeper SCP SSP 8XX CNAM LIDB LNP WIN/AIN IMT Media Gateway SGCP MGCP H.248 MEGACO H.323 Q.931 H.225/RAS H.245 SIP+ SS7 SCTP TCAP TRIP H.225 SCTP AS SIP SCP STP SIP Proxy SG SIP Softswitch/ Signaling Gateway

11. 11 Phases of Network Evolution PSTN (Wireline/ Wireless) SS7/ HLR 2G/2.5G Packet Backbone Phase 1: Transport cost optimization –Data Offload –Tandem Offload –Wireless Tandem –Leveraging AIN services –Converged Transport –Co-existence of TDM and IP networks PBX Enterprise ISUP/TCAP/ MAP ISP Enterprise/SMB PBX/ Key System IAD H.323SIP SIP/H.323/ JAIN Application Server SIP/H.323/ JAIN Application Server Phase 2: New Revenue generation –Out of region voice+data service delivery –Peering/Inter-working with H.323 & SIP Networks –Integration of best in Class Application Servers –Enhanced Services for Businesses 3G RNC IAD Residence Phase 3: Converged Multi-Service Access Networks –Wireline / Wireless/ TDM/ ATM/ IP networks –Business, Residential & Wireless end-user segments –Ubiquitous service delivery via common infrastructure Gateway/ RAS Gateway/ RAS Softswitch/ Signaling Gateway