Real-Time Service (RTS) Introduction

1. Real-Time Service (RTS) Introduction Barry Sweeney, Ph.D. 703-676-2282 sweeneyb@saic.com September 2007

2. Agenda • Legacy Voice and Video Technologies • IP RTS Technologies • IP RTS Information Assurance • IP RTS Quality of Service • Future Technologies

3. Legacy Voice and Video Technologies • History • Standards • Development Model • Cost Model

4. Legacy Voice and Video Technology Overview (History) • The first commercial end instruments (EIs) were offered by Bell Telephone in 1877 • Long haul was provided by Western Union • Business service cost $40.00/yr and Residential service cost $20.00/yr • By 1877 over 600 EIs were deployed and Central Office Exchanges were built to handle the switching of calls • COs is still the term used today

5. Legacy Voice and Video Technology Overview (History Cont.) • As the number of EIs increased it became more cost effective to provide the switching at the customer locations • Customer site centralized switches became known as Private Branch Exchanges (PBXs) and provide: • Call routing • Basic call features (call hold, call transfer, call waiting, etc.) • Conference calling • Call Detail Records (Billing Information) • EIs still belonged to the Telco and were rented to the customer resulting in the name Customer Premise Equipment (CPE) • PBXs connect to the PSTN via End Offices (EOs) • See next slide

6. Legacy Voice and Video Technology Overview (History Cont.) • As the size of the network increased PBXs were serviced by more power switches called End Offices (EOs) • Lowest level of a PSTN switch • Also known as Class 5 switches • Typically include the PBX functions, but are more powerful with increased functions • Network management • More robust feature set (release to pivot, conferencing, etc.) • Test capabilities (i.e., line tests) • Timing • As the number of EOs increased, Tandem Switches were created to link the EOs’ together • Also known as Class 4 switches • Do not service EIs • Sometimes combined with an EO and called a Multifunction Switch (MFS)

7. Legacy Voice and Video Technology Overview (Standards) • Numbering Plan • In US we use the North American Numbering Plan • Country Code (North America is 0015) • Area Code (703) • Central Office Exchange (676) • Port and Circuit ID (2282) • My Phone Number at work is 703-676-2282 • Developed by Telcordia Technologies (formerly Bell Labs) • Bellcore Generic Requirements • Requirements that a TDM switch vendor must meet to ensure interoperability • International Telecommunications Union (ITU) • CODECs (G.711, G.729, H.264, etc.) • Physical Transmission Requirements (H.320, Q.931, etc.) • Telephone Quality (P.800, P.862, P.1010, etc.) • Over the last 30 years interoperability issues resulting from implementation of TDM standards have been largely resolved

8. Legacy Voice and Video Technology Overview (Development Model) • Single Physical Appliance • Proprietary Operating System • Proprietary (protected) Application • 20 year depreciation model • Only external interfaces were standardized • Closed network management network • Signaling and Bearer typically travel same path • Bearer in B channel and Signaling in D channel of a PRI • 23B + D = 24 channels in a PRI • CAS and SS7 are in-band signaling protocols

9. Legacy Voice and Video Technology Overview (Cost Model) • Historically, the Telcos have generated revenue by charging for every minute a session is active • Call Detail Records in the EO maintain a record of the sessions • Modem data connections were treated as single voice sessions • Call hold times averaged 5 minutes in the pre Internet days • Increase in Internet related calls impacted voice traffic engineering • Each voice session was exactly 64 kbps of bandwidth or 1 DS0 on a T1 circuit • Video and ISDN muxed together multiple DS0s • TDM switch was typically most expensive element • Sometimes in Millions of dollars including OA&M

10. IP RTS Technologies • RTS Technology Overview • VoIP • Video over IP • Standards • Signaling, Bearer, and Network Management Characteristics • Development Model • Cost Model

11. IP RTS Technologies (Overview)

12. IP RTS Technologies (VoIP) Traditional Digital TDM Voice Transmission Analog/Digital Converter Digital Samples Digital Network Digital Samples Digital/Analog Converter Analog Voice Analog Voice Analog Voice Analog Voice Voice over IP Transmission Analog/Digital Converter Digital Samples Encoder De-Jitter Buffer Decoder Digital/Analog Converter RTP Packetizer RTP De-Packetizer UDP UDP IP IP Link Link Physical Physical IP Network

13. IP RTS Technologies (Legacy Video Technologies (H.320 Video)) Analog/Digital Converter Digital Frame Color Transformation Re-sampling Analog Video Capture Subsystem H.261/H.263 Formatted Frame H.261/H.263 Encoder Digital Network H.261/H.263 Encoder Compressed Frame Uncompressed Frame Color Transformation Re-sampling Modified Frame for Display Display Subsystem

14. IP RTS Technologies (H.323/SIP Video) Analog/Digital Converter Digital Frame Color Transformation Re-sampling Analog Video Capture Subsystem H.261/H.263 Formatted Frame H.261/H.263 Encoder RTP Packetizer RTP De-Packetizer De-Jitter Buffer Compressed Frame UDP UDP IP IP Link Link Physical Physical IP Network H.261/H.263 Encoder Uncompressed Frame Color Transformation Re-sampling Modified Frame for Display Display Subsystem

15. IP RTS Technologies (Standards) • Combination of Legacy Standards and New Standards • North American Numbering Plan • E.164 is the primary approach taken today • May be replaced by concept known as ENUM – RFC 2916 • Bellcore Generic Requirements • For interfacing to legacy PSTN systems • International Telecommunications Union (ITU) • CODECs (G.711, G.729, H.264, etc.) • Signaling • Session Initiation Protocol (SIP) - RFC 3261 • ITU H.323 • Aggregation of several H.series standards • Bearer • Real-time Transport Protocol (RTP) – RFC 3550 • Network Management • Simple Network Management Protocol (SNMP) – RFC 3414 • Secure Shell (SSHv2) – RFC 4251 • Hyper Text Transport Protocol over Secure Socket Layer (SSL) (HTTPS) – RFC 2818

16. IP RTS Technologies (Development Model) • Distributed Systems • Multiple appliances with different functionalities • Typically multivendor • Call Control Agent (CCA) from Vendor A • LAN from Vendor B • TDM Switch from Vendor C • Firewall from Vendor D • Off-the Shelf Operating System (Windows, Unix, LINUX, etc.) • Proprietary (protected) Application • 5 – 10 year depreciation model • Only external interfaces are standardized • Open and Closed network management networks • Signaling and Bearer typically travel different paths • See next slide

17. IP RTS Technologies (Signaling, Bearer, and Network Management Characteristics) • Signaling is hierarchical • Bearer does not necessarily take the same path as signaling • Network Management traffic is often in-band

18. PER IP RTS Technologies (End-to-End Functional Components) WAN or Core Network Edge or Business Trusted Relationships Required Among All Appliances • NM/PBNM • Control to SS, CCA, & Routers • LCC • Session Control and Signaling (SCS) • State of Local LAN Sessions • State of Local Access Layer Sessions • Local Access Bandwidth Used • Local Access Bandwidth Available • Directs CCA SCS to Modify Resources • Network Management • Local Directory Services • Media Gateway Controller • Appliance Authentication and IA Services • EI & User Authentication and Authorization • User Features and Services • Softswitch (SS) • Session Control and Signaling (SCS) • State of RTS WAN Sessions • Access Layer SLA Enforcer • Process Input from Closed Loop System • SLA Performance Monitoring • Directs SS SCS to modify resources • CCA • Signaling Gateway • Media Gateway Controller • Global Directory Services • Network Management • Appliance Authentication and IA Services Media Gateway • End Instrument • Signaling Client • COS Packet Marking • CCA Authentication • User Interface • RTS Aware Firewall & CER • Traffic Conditioning • Bandwidth Management • PHB • Topology Hiding • Opening and Closing “Pinholes” Access Circuit Converged LAN Media Gateway SS & LCC/ASAC NM Signaling Bearer Router Control

19. IP RTS Technologies (IP End-to-End Session) PRI/SS7 Signaling Bearer SS SS MFS MFS PRI PRI IP Core PER PER Enclave A Enclave B CER CER PRI /SS7 PRI /SS7 PRI PRI EO CCA CCA EO Phone A

20. IP RTS Technologies (Cost Model) • Flat rate for RTS services • Voice bandwidth based on 92 Kbps per voice session • 102 Kbps for IPv6 voice sessions • Video bandwidth based on 500 Kbps per traditional 384 Kbps video session • SLAs are typically data centric • Typically LAN is most expensive element due to reliability requirements • 99.999% reliable • Power backup is often a considerable cost

21. IP RTS Information Assurance • IA Architecture Approach • Methods for Assessing Risk • IA Architecture Considerations • Example RTS IA Architecture • Example RTS LAN

22. IP RTS Information Assurance (Information Assurance Process) Document IA Threats Additional IA Requirements Develop Generic CMs Develop IA Architecture Industry and User Community Specify IA Requirements

23. IP RTS Information Assurance (Risk Assessment Method) NOTE: Score = Impact X Likelihood ETSI TISPAN/TIPHON Risk Assessment Model

24. IP RTS Information Assurance (IA Architecture Considerations) • Physical Security • RTS Appliance Security Architecture • Generic in respect to vendor solutions • User roles • Hardened Operating Systems • Auditing • Application level security • Redundant Systems • RTS Component Interactions • VLANs • Segmentation • Network Management • RTS Protocol Architecture • Signaling • Transport • Network Management • Firewalls and NATs

25. End Instrument End Instrument IP RTS Information Assurance(Example RTS IA Architecture) Protocol (IA Protocol) PRI/CAS SRTP Media Gateway Protocol (IA Protocol) Only Standardized Protocols PSTN Proprietary Protocols Allowed Data Firewall SIP(TLS) H.248/MGCP/MEGACO(IPSec) SIP(TLS)/H.323(IPSec) IP WAN Switch Customer Router LDAPv3/HTTPS Customer Edge Router CA/PKI Server RTS Firewall Switch SIP(TLS) SNMPv3/SSH/TLS1.0(SSL3.1) RTS IA & Profile Services RTS User Feature & Services RTS Signaling Services RTS NM Services Local Directory Services SS NMS CCA

26. IP RTS QoS • Call Control Budgets • DiffServ • Per Hop Behaviors • Explicit Congestion Notification • RSVP • Bandwidth Brokers

27. IP RTS QoS (Call Control Budgets) • Current RTS Architectures primarily use Call Control Agents (CCAs) as the mechanism for avoiding congestion • Each site is assigned a predefined budget • Each call is allocated against budget • When budget is full CCA blocks the call and plays a trunk busy signal • CCA is typically operated by the business (replaces PBX) • Softswitch polices the CCA to ensure that the CCA stays within its subscribed budget • Softswitch is owned by the TELCO (augments EO and Tandem Switch)

28. IP RTS QoS (DiffServ) • Differentiated Services (DS) is an architecture for indicating a traffic class in the IP header (RFC 2474) • 6 bit field in IP header (allows 64 markings) • Markings are called DiffServ Code Points • Marking is performed by layer 3 traffic conditioners or by end instrument • Marking may be based on incoming port, IP address, protocol, VLAN tag, etc. • Marking used by routers to discriminate between different classes of traffic by placing packets into different queues (also known as Per Hop Behaviors (PHBs)) • May also be used for traffic shaping or policing • Voice is typically placed in the Expedited Forwarding Queue (RFC 2598) along with the User Signaling (i.e., SIP, H.323, H.248, etc.) • EF queue is served before all other queues are served in accordance with its allocation • The router checks to see if any packets are in the EF queue before it services the other queues • All packets in EF queue are treated equally • Video is usually placed in the Assured Forwarding Queue (RFC 2597) • AF queues have 3 drop probabilities • AF queues are typically served in a Weighted Round Robin (WRR) approach

29. IP RTS QoS (ECN) • Explicit Congestion Notification (ECN) is a mechanism for signaling in the IP header or the RTP header the relative congestion experienced in the IP network • Documented in two Internet Drafts • “RTP Payload Format for ECN Probingdraft-alexander-rtp-payload-for-ecn-probing-02.txt” • “Admission Control Use Case for Real-time ECN draft-alexander-rtecn-admission-control-use-case-00.txt” • 2 bit field indicates whether congestion exists or when congestion thresholds are met • Bits 6 & 7 in the DS field when found in IP header • 2 bits between the version and the RTP sequence number in the RTP header • Each router in the bearer path that may experience congestion must participate • Requires the marking of every packet • Some IA concerns are associated with attacks that change the bits to indicate congestion is occurring when none is actually occurring • Reverse attack can be detected by sending probes preset to indicate congestion

30. IP RTS Technologies (ECN Flow) Signaling Bearer PRI/SS7 SS SS MFS MFS PRI PRI IP Core PER PER Enclave A Enclave B CER CER PRI /SS7 PRI /SS7 ECN Bits Set ECN Updates PRI PRI EO CCA CCA EO ECN Updates Phone A

31. IP RTS QoS (RSVP) • RSVP is an acronym for Resource Reservation Protocol (RFCs 2205 & 2208) • RSVP is typically used as a bandwidth reservation mechanism executed on a session-by-session basis • Reservation is evaluated on a hop-by-hop basis • Each path is allocated a budget and reservations are decremented against the budget • Sophisticated mechanism for efficiently utilizing network resources • Requires CCA to interact with routers • Aggregated RSVP was developed to deal with scalability issues (RFC 3175) • SIP with Preconditions is designed to check with RSVP to ensure resources are available prior to establishing a session • Currently, RSVP is typically considered by industry to be a Cisco approach • Juniper MPLS-TE RSVP implementation conflicts with Cisco RSVP implementation • Juniper does not implement RSVP for individual sessions • RSVP is deemed by some to be a IA risk due to the unregulated fields • Allows for possibility of a covert channel

32. IP RTS Technologies (RSVP) Signaling Bearer RSVP Precondition PRI/SS7 SS SS MFS MFS PRI PRI IP Core PER PER Enclave A Enclave B CER CER PRI /SS7 PRI /SS7 SIP With Preconditions PRI PRI EO CCA CCA EO Phone A

33. IP RTS QoS (Bandwidth Broker) • Requires a centralized server to know status of RTS network • CCAs provide status to centralized server on current counts • Routers provide bandwidth utilization on each circuit and routing table/MPLS paths • Bandwidth Broker (BB) periodically calculates budgets for each CCA and updates CCA • Does not conform easily to commercial model where enclaves have contractual budgets, which are managed at the enclave level

34. IP RTS Technologies (Bandwidth Broker) CCA Budgets Routing Tables and Queue Congestion PRI/SS7 SS SS MFS MFS PRI PRI IP Core PER PER Enclave A Enclave B Bandwidth Broker CER CER PRI /SS7 PRI /SS7 SIP With Preconditions PRI PRI EO CCA CCA EO Phone A

35. Future Technologies • IMS • Unified Communications • Wireless Expansions • IPv6 Mobility

36. Future Technologies (IMS) • IP Multimedia Subsystem • An architectural framework for delivering IP multimedia to mobile users. • Developed by 3rd Generation Partnership Project (3GPP) • An attempt to develop mobile wireless beyond the Global System for Mobile (GSM) standard • Vision was to introduce Internet services over GPRS (General Packet Radio Service) • Medium speed data transfers • SIP is an important protocol in the IMS architecture • Many vendors market IMS capabilities

37. Future Technologies (Unified Communications) • Unified Communications • A new buzzword indicating the use of IP to deliver multimedia services • Google search shows that Nortel, Cisco, Avaya, and Microsoft market Unified Communications • Typically focused on wireline users • Some capabilities are targeted at wireless users • Types of multimedia services provided include: • Instant Messaging • E-mail • Voice • Video • Whiteboard • At this time, most vendor solutions are not interoperable

38. Future Technologies (Wireless Expansion) • Wireless is becoming more predominant in every facet of telecommunications • Wireless LANs to support mobile users within a campus LAN is becoming more predominant • PDAs use continues to expand • Increased use of mobile phones to replace traditional desktop phones and residential phones • Significant threat to traditional telecom companies due to change in business model • Recent FCC decision to auction wireless spectrum allowing open network • Allows users to connect to any service • Google, Yahoo, Skype, etc. • SIP allows users of multiple extension phone to subscribe to multiple carriers

39. Future Technologies (IPv6 Mobility) • IPv6 allows nodes to move around the Internet, but be reachable using their “home” IP address • Involves the concept of a “home agent” • Typically a router • Mobile node registers with home agent • Home agent forwards all traffic destined to “home” IP address to the temporary “mobile” IP address • Relies on Internet QoS to ensure that quality is acceptable • Can cause issues with CCA budget since bearer traffic affects remote nodes access bandwidth budget while the remote CCA is unaware that the mobile node is generating traffic • Relies on VPN or secure IA architecture to ensure that mobile node does not introduce risk to “home” network

40. Questions ?