1. December 5, 2003FG3 Report FOCUS GROUP 3 Interoperability Report to NRIC VI Council December 5, 2003 Cliff Naughton (Boeing)

2. December 5, 2003FG3 Report MISSION The Committee [FG3] will prepare analyses and, where appropriate, make recommendations for improving interoperability among networks to achieve the objectives that are contained in Section 256 of the Telecommunications Act of 1996, with particular emphasis on ensuring "the ability of users and information providers to seamlessly and transparently transmit and receive information between and across telecommunications networks."

3. December 5, 2003FG3 Report FG3 Participants

4. December 5, 2003FG3 Report FG3 Status Positive, Co-operative team dynamic –Team Composition (31 members) Service Providers (wireline, wireless), Vendors, OEMs, Customers, Industry associations Methodology –Interoperability focus is Voice-over-IP networks with circuit switched networks, both wireline and wireless –Gap analysis from published work of standards bodies (ITU, IETF, etc.) and accepted industry practices to derive best practices and recommended areas of research

5. December 5, 2003FG3 Report Scope of VoIP Interoperability Report

6. December 5, 2003FG3 Report Scope of VoIP Interoperability Report TDM IP SP A IP SP B PSTN SP A PSTN SP B SIP/H.323 Public ENUM DNS SIP/H.323 VoIP QoS VoIP QoS VoIP QoS SIP, SIP-T, BICC, H.323, CMSS TDM LNP VoIP=Voice/RTP/UDP/IP Internal to SP Interfaces Internal to SP Interfaces MEGACO/ H.248 MEGACO/ H.248 SS7 TDM SIP/H.323 SS7 In Scope Out of Scope SS7 Private ENUM DNS Non-ENUM Private Directory ???

7. December 5, 2003FG3 Report 1. Executive Summary................................................................................................................... 3 2. Background and Scope of Focus Group 3................................................................................ 6 2.1 Structure of NRIC VI.......................................................................................................... 6 2.2 Scope of NRIC VI FG3 Interoperability Effort.................................................................... 6 2.3 FG3 Team Members....................................................................................................... 11 3. VoIP Interoperability Gap Analysis.......................................................................................... 13 3.1 Signaling Architectures.................................................................................................... 15 3.1.1 Signaling System 7................................................................................................ 15 3.1.2 Session Initiation Protocol..................................................................................... 16 3.1.3 SIP to PSTN Interworking...................................................................................... 19 3.1.4 Bearer Independent Call Control........................................................................... 22 3.1.5 H.323 to PSTN Interworking.................................................................................. 24 3.1.6 H.323 to SIP Interworking...................................................................................... 25 3.1.7 Signaling Transport................................................................................................ 26 3.1.8 Network Management Control Between Different Networks and Applications (e.g., Wireline and Wireless)............................................................. 27 3.2 Call Control Architectures................................................................................................ 29 3.2.1 Packet Tandem Architectures................................................................................ 29 3.2.2 PacketCabl  Architectures................................................................................. 30 3.3 Voice Over Wireless........................................................................................................ 33 3. VoIP Interoperability Gap Analysis.......................................................................................... 13 3.1 Signaling Architectures.................................................................................................... 15 3.1.1 Signaling System 7................................................................................................ 15 3.1.2 Session Initiation Protocol..................................................................................... 16 3.1.3 SIP to PSTN Interworking...................................................................................... 19 3.1.4 Bearer Independent Call Control........................................................................... 22 3.1.5 H.323 to PSTN Interworking.................................................................................. 24 3.1.6 H.323 to SIP Interworking...................................................................................... 25 3.1.7 Signaling Transport................................................................................................ 26 3.1.8 Network Management Control Between Different Networks and Applications (e.g., Wireline and Wireless)............................................................. 27 3.2 Call Control Architectures................................................................................................ 29 3.2.1 Packet Tandem Architectures................................................................................ 29 3.2.2 PacketCabl  Architectures................................................................................. 30 3.3 Voice Over Wireless........................................................................................................ 33 Scope of VoIP Interoperability Report

8. December 5, 2003FG3 Report 3.4 Inter-Provider Interfaces.................................................................................................. 40 3.4.1 Quality of Service................................................................................................... 40 3.4.2 Inter-Provider Usage Metering (Reciprocal Compensation).................................. 49 3.4.3 VoIP Encoding (PCM/TDM)................................................................................... 52 3.4.4 Interoperability With PSTN Station Signaling (e.g., FLASH, DTMF Digits, Point of Sale)......................................................................................................... 56 3.5 Directory Services............................................................................................................ 58 3.5.1 Local Number Portability, North American Numbering Plan................................. 58 3.5.2 ENUM/DNS............................................................................................................ 61 3.6 Safety and Security......................................................................................................... 73 3.6.1 Support of CALEA.................................................................................................. 73 3.6.2 Teletype Technology (TTY/TDD)........................................................................... 74 3.6.3 E911 VoIP Interoperability..................................................................................... 76 3.6.4 Network Address Translation (NAT)...................................................................... 78 3.6.5 Firewalls................................................................................................................. 79 Scope of VoIP Interoperability Report

9. December 5, 2003FG3 Report It is evident that ENUM technology is still evolving, as is its deployment and support infrastructure. The industry is making progress on resolution of many outstanding issues. NRIC FG3 makes the following recommendations: 1.The U.S. Government should continue to encourage, support and participate in ENUM deployment at the technical interchange level. 2.The U.S. should formally opt in to the e164.arpa global public ENUM DNS domain. 3.Government and Industry should work together to assign responsibility for administration of the subdomains of 1.e164.arpa corresponding to NANP and U.S. telephone numbers. The Tier 1 Registries for Country Code 1 should be identified, and processes for managing this data established. 4.Providers implementing alternative deployments to the e164.arpa public ENUM should insure that their deployments provide methods for maintaining the synchronization of their data with the public ENUM and the LNP database, as well as other applicable Number Portability databases in the PSTN. 5.Managers of networks containing clients which use ENUM should provision their local DNS servers with a modern DNS implementation that supports NAPTR records and DNSSEC. 6.Providers implementing authoritative DNS server for ENUM domains should provision those servers per IETF Best Current Practices (currently BCP 40 and BCP 16). Highlights of Recommended Actions for the FCC

10. December 5, 2003FG3 Report Address PSTN functionality of call control protocols (SS7, SIP, SIP-T, BICC) within industry bodies such as IETF & SIP Forum Call control architectures such as Packet Tandem and PacketCable should be prepared to open these networks for direct interconnect to other IP networks as they evolve using standard signaling protocols The industry needs to evolve voice over wireless (WWAN, WLAN, satellite) that addresses a common IP platform that supports end-to-end connectivity and interoperability The operational and standards bodies should investigate the possibility of creating a standardized inter-domain QoS metric data interchange format. For example, the extended Real-Time Control Protocol (RTCP) from the IETF could be employed to report on loss and delay variation between service provider and/or enterprise-controlled VoIP gateways. Further work is needed for the harmonization of QoS specifications for wireline networks (e.g., in the ITU and ATIS) and those for wireless networks (e.g., 3GPP). It is recommended that the Standards Development Organizations (SDOs) finish their work in the area of TTY transmission on VoIP networks. This is currently work in progress with an expectation of completion within 12 months. Highlights of Recommended Actions for the Industry

11. December 5, 2003FG3 Report Questions? FG3 Interoperability Report