Alcatel 7515 Media Gateway Product Description Release 2.0-1 -
ABOUT THIS DOCUMENT... 6 1 PRODUCT OVERVIEW... 7 1.1 INTRODUCTION... 8 1.2 ALCATEL 7515 MEDIA GATEWAY KEY BENEFITS...11 1.3 ALCATEL 7515 MEDIA GATEWAY FEATURES... 12 1.3.1 GENERAL FEATURES... 12 1.3.2 VOICE, FACSIMILE, AND PUBLIC SWITCHED TELEPHONE NETWORK FEATURES... 14 1.3.3 DENSITY AND SCALABILITY... 15 1.3.4 PERFORMANCE... 15 1.4 MANAGEMENT... 16 1.5 APPLICATIONS... 16 1.5.1 EMERGING SERVICE PROVIDERS: TRUNK TOLL BYPASS APPLICATION... 16 1.5.2 COMPETITIVE ACCESS PROVIDERS: VOIP FOR BROADBAND ACCESS... 17 2 ARCHITECTURE AND HARDWARE...19 2.1 INTRODUCTION... 20 2.2 ARCHITECTURE... 20 2.2.1 SOFTWARE MODULES... 21 2.2.2 CENTRAL FORWARDING... 22 2.2.3 VOICE PROCESSING... 23 2.3 SYSTEM COMPONENTS... 23 2.4 MAINBOARD MODULES...25 2.4.1 SYSTEM CONTROL MODULE (SCM)... 25 2.4.2 CIRCUIT PROCESSING MODULE... 25 2.4.3 PACKET PROCESSING MODULE... 27 2.4.4 ALARM MODULE... 27 2.4.5 CLOCK MODULE... 28 2.4.6 POWER SUPPLIES... 28 2.5 REAR TRANSITION MODULE... 29 2.6 FAN TRAYS... 29 2.7 VOICE/FAX PROCESSING MODULES... 30 2.8 ALCATEL 7515 MEDIA GATEWAY CONFIGURATIONS... 31 2.9 HIGH AVAILABILITY... 33 2.10 DIAGNOSTICS... 33 FEATURES AND SERVICES... 34 3.1 INTRODUCTION... 35 3.2 INTERFACES SUPPORTED... 35 3.3 CONNECTION CONTROL AND SIGNALING... 36 3.4 PROTOCOLS SUPPORTED... 37 3.4.1 MEGACO V1.0... 37 3.4.2 SIGTRAN... 41 3.4.2.1 SCTP... 42 3.4.2.2 IUA... 43 3.4.2.3 MULTI VENDOR INTEROPERABILITY... 45 3.5 VOICEBAND SERVICES... 45-2 -
3.5.1 SILENCE SUPPRESSION... 46 3.5.2 COMFORT NOISE GENERATION... 46 3.5.3 ECHO CANCELLATION... 46 3.5.4 FACSIMILE/MODEM BYPASS... 47 3.5.5 FACSIMILE RELAY... 47 3.6 REDUNDANCY, RELIABILITY, AND AVAILABILITY... 48 3.6.1 FAULT TOLERANT APPLICATION MANAGEMENT... 48 3.6.2 CHASSIS MANAGEMENT MODULE PROCESS... 49 3.6.3 REDUNDANT EXTERNAL CLOCK... 49 3.6.4 REDUNDANT SIGNALING... 50 3.6.5 REDUNDANT DATA... 50 3.7 IP SERVICES... 50 3.7.1 INTERNET PROTOCOLS... 51 3.7.2 ROUTING INFORMATION PROTOCOL... 51 3.7.3 OPEN SHORTEST PATH FIRST... 51 3.8 DOMAIN NAME SERVICE... 52 4 OAM&P... 52 4.1 INTRODUCTION... 53 4.2 ON BOARD MANAGEMENT... 53 4.2.1 FAULT MANAGEMENT... 53 4.2.2 CONFIGURATION MANAGEMENT... 54 4.2.3 PERFORMANCE MANAGEMENT... 54 4.2.4 SECURITY MANAGEMENT... 55 4.3 ELEMENT MANAGEMENT... 56 4.3.1 COMMAND LINE INTERFACE... 56 ABBREVIATIONS... 57 APPENDIX A SPECIFICATIONS... 60 APPENDIX B STANDARDS... 61 APPENDIX C PRODUCT LIST... 64 FIGURE: FIGURE 1 NEXT GENERATION NETWORK MODEL... 8 FIGURE 2 ROLE OF ALCATEL 7515 MEDIA GATEWAY WITHIN NGN... 9 FIGURE 3 ALCATEL 7515 MEDIA GATEWAY IN A TOLL BYPASS APPLICATION... 17 FIGURE 4 ALCATEL 7515 MEDIA GATEWAY SUPPORTING VOIP BROADBAND APPLICATIONS... 18 FIGURE 5 A7515 NON-REDUNDANCY SYSTEM ARCHITECTURE OVERVIEW... 20 FIGURE 6 SOFTWARE MODULES IN AN ALCATEL 7515 MEDIA GATEWAY... 21-3 -
FIGURE 7 CENTRAL IP FORWARDING... 23 FIGURE 8 ALCATEL 7515 MEDIA GATEWAY REAR VIEW... 24 FIGURE 9 ALCATEL 7515 MEDIA GATEWAY FRONT VIEW... 24 FIGURE 10 INTERFACES SUPPORTED... 35 FIGURE 11 PROTOCOLS SUPPORTED BY AN ALCATEL 7515 MEDIA GATEWAY... 37 FIGURE 12 MEGACO CALL FLOW... 41 FIUGRE 13 PROTOCOL STACK DIAGRAM... 42 TABLE: TABLE 1 RELATED DOCUMENTS... 6 TABLE 2 ALCATEL 7515 MEDIA GATEWAY CAPACITY... 9 TABLE 3 ALCATEL 7515 MEDIA GATEWAY...11 TABLE 4 ALCATEL 7515 MEDIA GATEWAY GENERAL FEATURES... 12 TABLE 5 ALCATEL 7515 MEDIA GATEWAY EXAMPLE CONFIGURATIONS... 15 TABLE 6 ALCATEL 7515 MEDIA GATEWAY PERFORMANCE... 15 TABLE 7 SOFTWARE MODULE FUNCTIONS... 21 TABLE 8 SYSTEM CONTROL MODULE DETAILS... 25 TABLE 9 MAIN BOARD WITH T1/E1 INTERFACE... 26 TABLE 10 PACKET PROCESSING MODULE CHARACTERISTICS... 27 TABLE 12 PM-VPM-480 MODULE DETAILS... 30 TABLE 13 VOIP FUNCTIONS PROCESSED BY THE MODULES... 31 TABLE 14 THE BOARD CONFIGURATION... 32-4 -
TABLE 15 MEGACO MESSAGES SUPPORTED... 38 TABLE 16 REAL TIME TRANSPORT PROTOCOL ID FORMAT... 40 TABLE 17 IUA SUPPORTS THE FOLLOWING MESSAGES:... 43 TABLE 18 CODECS SUPPORTED... 45 TABLE 19 ECHO CANCELLATION SUPPORTED... 47 TABLE 20 OPEN SHORTEST PATH FIRST AREA TYPES SUPPORTED... 51 TABLE 21 SYSTEM STATISTICS PROVIDED... 54 TABLE 22 OPERATIONAL STATISTICS... 55 TABLE 23 ALCATEL 7515 MEDIA GATEWAY PHYSICAL SPECIFICATIONS... 60 TABLE 24 PRODUCT NUMBERS FOR HARDWARE MODULES... 64 TABLE 25 PRODUCT NUMBERS FOR EQUIPMENT AND SPARES... 64 TABLE 26 PART NUMBERS OF CABLES AND ACCESSORY KITS... 65 TABLE 27 PART NUMBER OF SOFTWARE... 65-5 -
About this Document Scope This Product Description introduces the Alcatel 7515 Media Gateway, Release 2.0,and describes how it connects circuit switched telephone networks to Ethernet packet switching networks. The document presents an overview of Alcatel 7515 Media Gateway, focusing on it Voice over IP (VoIP) and Fax over IP (FoIP) trunking gateway applications. Readership This document is intended to be used by network planners, and other desiring to gain an overview of the 7515 Media Gateway as a VoIP or FoIP trunking gateway. Contents in Brief This document contains the following chapters: Chapter 1 Product Overview describes the features and key benefits of on Alcatel 7515 Media Gateway,as well as gateway management and applications Chapter 2 Functional Architecture and Software describes the architecture and software system components of an Alcatel 7515 Media Gateway Chapter 3 Features and Services describes features and services supported by the Alcatel 7515 Media Gateway Chapter 4 Operation, Administration Maintenance and Provisioning provides information concerning Operations, Administration, Maintenance and system configuration. Related Documents Table1 lists the documentation that is available for the Alcatel 7515 Media Gateway Release 2.0. Title Alcatel 7515 Media Gateway Installation and Configuration Guide A7515 Media Gateway User Manual A7515 Media Gateway GEM User Guide Part Number 3FZ08061AAAA 3FZ08059AAAA 3FZ08060AAAA Table 1 Related Documents Trademarks The Alcatel word and Alcatel logo are registered trademarks and service marks of Alcatel. All other trademarks are the property of their respective owners. - 6 -
document, use and communication of its content not permitted without written authorization from Alcate s l. 1 Product Overview This chapter provides an overview of the Alcatel 7515 Media Gateway product. The following sections are presented: Introduction Alcatel 7515 Media Gateway Key Benefits Alcatel 7515 Media Gateway Features Management Applications - 7 -
1.1 Introduction The Alcatel 7515 Media Gateway (MG) is an industry leading multi-service gateway that supports IP-based voice, fax, data and trunk and access signaling gateway services on any port at any time. The Alcatel 7515 MG offers a rich set of services in a very compact two-rack unit. This cost-effective platform is ideally suited for distributed deployment in multi-service next generation network (NGN) points of presence (PoPs). As one of the key elements of Alcatel s NGN solution, the Alcatel 7515 MG provides seamless inter-working of voice connections between the public switched telephone network (PSTN) or Integrated Service Digital Network(ISDN) and IP networks. Featuring a reliable hardware platform with advanced digital signal processor (DSP) technology and IP forwarding architecture, the Alcatel 7515 MG offers high performance packet voice processing and signaling. Thanks to the use of open standard protocols, the Alcatel 7515 MG can be integrated into any multi-vendor next generation network. With the Alcatel 7515 MG, service providers can address today s challenges while evolving toward tomorrow s NGN. SS7 SS7 Call Control & Services TDM Int erf Int erf TDM Softswitch ac ac TDM Packet Network TDM Alcatel 7515 Media Gateway Alcatel 7515 Media Gateway 0105_fig1_ed02 figure 1 Next Generation Network Model The NGN architecture comprises the following layers: Services and Management layer, which delivers services and applications, independent of network infrastructure Signaling and Control layer, which manages call control and signaling Media layer, which is responsible for transport, switching, and mediation. - 8 -
Figure 2 illustrates the role of the Alcatel 7515 Media Gateway in NGNs. In the NGN architecture, the Alcatel 7515 Media Gateway is located in the media layer, providing inter-working of different bearer traffic. In the signaling and call control layer, the softswitch performs signaling, interworking between VoIP protocols and Public Switched Telephone Network (PSTN) protocols. In response to softswitch instructions, the Alcatel 7515 Media Gateway allocates media processing resources, interconnects TDM DS0 (timeslots) to voice packet streams, processes media streams, and performs silence suppression and other signal processing functions. Service & Management Layer Application Servers and Operation Support Systems Signaling & Control Layer Softswitch Media Layer PSTN Alcatel 7515 Media Gateway IP Backbone Alcatel 7515 Media Gateway PSTN 0103_fig2_ed03 figure 2 Role of Alcatel 7515 Media Gateway within NGN The Alcatel 7515 Media Gateway works in conjunction with a softswitch and internationally proven standardized Signaling System No. 7 (SS7) network components to offer end to end NGN solutions. Designed for deployment in small to medium tandem VoIP Points of Presence (PoPs), the Alcatel 7515 Media Gateway supports the Megaco/H.248 protocol, as well as the latest features in packet voice processing. The Alcatel 7515 Media Gateway supports a Channelized T1 or Channelized E1 PSTN interface. 20 Alcatel 7515 Media Gateways in the American National Standards Institute (ANSI) configuration, or in the European Telecommunications Standards Institute (ETSI) configuration can be installed in a 2,20 meter (standard 7 foot) equipment rack. Details on the Alcatel 7515 Media Gateway capacity are shown in Table 2. Table 2 PSTN Interfaces Alcatel 7515 Media Gateway Capacity Ports using T1 interface (in American National Standards Institute (ANSI) configuration) Maximum Capacity per Gateway Up to 384 VoIP calls - 9 -
Ports using E1 interface (in ETSI European Telecommunications Standards Institute (ETSI) configuration) Up to 480 VoIP calls - 10 -
1.2 Alcatel 7515 Media Gateway Key Benefits Featuring a carrier grade platform and a scalable architecture, the Alcatel 7515 Media Gateway is specifically designed to meet stringent operator requirements for Next Generation media gateway applications. Table 3 lists key features uniquely distinguishing the Alcatel 7515 Media Gateway in the media gateway market. Table 3 Alcatel 7515 Media Gateway Key Benefits Multi-service(trunk/access/signaling) Gateway Operational cost savings resulting from compact size and low power consumption Advanced platform architecture, built to excel in carrier environment Description The Alcatel 7515 Media Gateway can act as multi-service gateway which includes Trunking GW, Access GW and signaling GW service with same software. Up to 20 ANSI or ETSI configured Alcatel 7515 Media Gateways can be fit into a 2,20 meter (standard 7 foot) Telco rack, saving valuable Central Office (CO) space. High performance and reliability-vxworks OS provides carrier proven, reliable, flexible methods of delivering multiple service Support for both ANSI and ETSI configurations Latest Generation DSP technology providing superior Voice Quality Industry Leading Management Solution Open Standard Protocols Extensive Compatibility with the Alcatel 7515 Media Gateway The Alcatel 7515 Media Gateway can be provided with an E1 interface to interoperate with ETSI configurations, or with a T1 interface to interoperate with ANSI configurations. The Alcatel 7515 Media Gateway supports both electrical and optical interfaces. The Alcatel 7515 Media Gateway includes a pool of high density DSP based modules offering G.711, G.726, G.729a/b, and G723.1 Voice Codecs, as well as G.168 compliant echo cancellation with 128 ms tail length. The DSPs port or interface for voice compression and packetization, silence suppression, echo cancellation, and other packet voice processing facilities. The Alcatel 7515 MG EM offers Simple Network Management Protocol(SNMP) controlled Graphical User Interface(GUI) management, supporting configuration, fault, performance, and security management Supports the industry-standard Megaco v1.0 signaling protocol to seamlessly inter-work with softswitch., e.g. Alcatel 5020 softswitch Smooth evolution toward later Alcatel Media Gateway models is ensured. - 11 -
1.3 Alcatel 7515 Media Gateway Features The Alcatel 7515 Media Gateway is based on a compact size chassis configuration that delivers a comprehensive feature set to support VoIP trunking applications. To access the PSTN network, the Alcatel 7515 Media Gateway supports a channelized T1 interface for the ANSI configuration and a channelized E1 interface for the ETSI Primary Rate Interface (PRI) configuration. The Alcatel 7515 Media Gateway supports up to two (plus two redundant) Ethernet ports to access the packet network. Routing functions in the Alcatel 7515 Media Gateway include Open Shortest Path First (OSPF) and Routing Information Protocol (RIP). The Alcatel 7515 Media Gateway is equipped with Fault Tolerant Application Management (FTAM) software and optional redundant hardware to ensure high availability operation. An extensive Command Line Interface (CLI) is provided to allow configuration control and management. 1.3.1 General Features Table 4 summarizes the Alcatel 7515 Media Gateway general features Table 4 Features Dimensions & Weight Alcatel 7515 Media Gateway General Features Number of slots 2 Supported Racks Power PSTN Interfaces Description Height: 8.8 cm (3.48 inch) Width: 48.1 cm (19.0 inch) Depth: 46 cm (18.1 inch) Weight (shelf only): 7.5 kg (16.5 lbs.) Weight (fully configured): 12 kg (26.4 lbs) Up to twenty Alcatel 7515 Media Gateways can be installed in one of these racks: -- 7 feet x 19 inch Network Equipment Building Standard (NEBS) compliant rack -- 7 feet x 23 inch NEBS compliant rack (included with gateway unit) -- 2200 mm x 600 mm ETSI rack 48 V Direct Current (DC) redundant A+B power feeds Maximum 300 W -- Up to 16 Channelized E1/T1 ports Packet Interfaces Up to 2 Fast Ethernet ports with 1+1 redundancy - 12 -
OAM&P/Signaling 10/100 Mbit/s Ethernet Management/Signaling Interfaces Up to 2 Fast Ethernet ports with 1+1 redundancy IP Services Signaling and Call Control IPv.4 OSPF v. 2.0 RIP v1.0, RIP v. 2.0 Telnet server Timing Internal Stratum 3 Reliability & Redundancy Quality of Service OAM&P Interoperability Certifications Megaco v. 1.0/H.248, SIGTRAN IUA Any PSTN Input/Output (I/O) Interface Building Integrated Timing Source (BITS) 1+1 redundancy of System Control Module, General Purpose Forwarding Module, power, fan trays, and backplane IP Type of Service (ToS) Element Management System with Event log, performance management fault monitoring and alarm generation Command Line Interface (CLI) Softswitch, 3rd party vendors See Appendix A - 13 -
1.3.2 Voice, Facsimile, and Public Switched Telephone Network Features The following list summarizes the voice and facsimile features supported by the Alcatel 7515 Media Gateway. Voice Features The following voice features apply: G.711 Comfort Noise Generation (CNG) Voice Activity Detection (VAD) Configurable voice frame size u law and a law companding G.729a/b 8 kbit/s G.723.1 6.3 kbit/s Dynamic Codec Negotiation G.168 compliant echo cancellation (up to 128 ms tail length) Adaptive Jitter Buffer, configurable, with an upper limit of 200 ms Fax Features The following facsimile features apply: Automatic fax detection FAX PCM pass-through (G.711). PSTN Features T.38 FoIP Real-time fax protocol. The following PSTN features apply: SS7 continuity test(cot) DTMF Transport Out-of-band (RFC 2833) In-band (G.711 pass through) TDM-Switching(TDM Hair-pinning) - 14 -
1.3.3 Density and Scalability The Alcatel 7515 Media Gateway chassis supports 2 slots and can be configured with three types of application specific modules: The Front Service Module (FSM) performs all management and routing functions. The Rear Transition Module (RTM) includes 8 PSTN interface for ETSI and ANSI and 2 Fast Ethernet interface. The Voice Process Module (VPM) Module contains DSPs designed to process TDM and packet voice traffic.. The number of Universal Modem Server modules determines the port capacity of the Alcatel 7515 Media Gateway. Table 5 shows some example configurations. Table 5 Number of Universal Modem Server modules 2 (maximum for ETSI configuration) 2 (maximum for ANSI configuration) Alcatel 7515 Media Gateway Example Configurations Capacity per Gateway Rack Capacity (20 Shelves/Rack) 480 DS0s 9600 DS0s 384 DS0s 7680 DS0s 1.3.4 Performance Shelf means one gateway viewed as one shelf in a rack. Table 5 assumes that in the ANSI/ETSI configuration there can be as many as twenty shelves/rack. Table 6 lists Alcatel 7515 Media Gateway performance characteristics. Table 6 Performance Area Alcatel 7515 Media Gateway Performance Values per Shelf Values per Rack (20 Shelves/Rack) Voice call hold time 3 minutes - Calls per second (ANSI) 2.1 42 Calls per second (ETSI) 2.7 54 Maximum Busy Hour Call Attempts (BHCA) for ANSI configuration Maximum BHCA for ETSI configuration 7,680 153,600 9,600 192,000-15 -
1.4 Management 1.5 Applications The Alcatel 7515 Media Gateway incorporates a complete set of system and network management tools, including an extensive CLI, local and remote Telnet, SYSLOG Services, and diagnostics for troubleshooting, as well as a Trivial File Transfer Protocol (TFTP) to realize file transfer. As a VoIP media gateway, the Alcatel 7515 Media Gateway is primarily responsible for performing media mapping or bearer conversion functions. The media gateway functionality includes circuit termination, packet handling, edge routing, and media processing. Incoming circuit switched bearer traffic is packetized to be transmitted over IP networks, and packet based traffic is reformatted to Pulse Code Modulation (PCM) and switched to the TDM interface connected to a PSTN. The following sections describe the role of the Alcatel 7515 Media Gateway in a trunk toll bypass application, and as a VoIP gateway for broadband access. 1.5.1 Emerging Service Providers: Trunk Toll Bypass Application The trunk toll bypass solution targets the international long distance voice calling market. The Alcatel 7515 Media Gateway is an ideal product for distributed VoIP trunking deployments in small to medium VoIP PoPs. It is an ideal solution for emerging service providers offering retail or wholesale voice over IP services cost effectively. Retail service providers sell time on an IP network to individual consumers or to small businesses on a retail basis. IP telephony wholesalers sell large blocks of long distance time between locations to Internet Telephony Service Provider (ITSP) and traditional carriers requiring large bandwidth. International service providers can bypass high international tariff rates, based on international accounting rates, to and from non liberalized markets. The trunk toll bypass solution allows these service providers to offer cheap long distance voice services over IP. Mass adoption of VoIP in a trunk toll bypass application is expected to grow as major carriers begin to offer cost effective and easy to implement solutions. The greatest hurdle toward attaining broad acceptance of VoIP in this segment has already been overcome by interfacing IP and PSTN networks with a high level of quality and reliability. Other attractive business developments are carrying VoIP over corporate Virtual Private Networks (VPNs), and the integration of phone, Private Branch Exchange (PBX), and fax machines. The Alcatel 7515 Media Gateway benefits, as related to the trunk toll bypass application, are: - 16 -
Entry level cost and density for distributed deployment Modularity and DS1 level interface granularity Supports ETSI and ANSI features for global deployments. In a trunk toll bypass application, a Local Exchange (LEX) carrier can be connected to an Alcatel 7515 Media Gateway by Intermachine Trunks (IMT). The softswitch interfaces with the SS7 network and controls the Alcatel 7515 Media Gateways using the Megaco v1.0 protocols, see Figure 3. SoftSwitch ISUP/SS7 Megaco/H.248 ISUP/SS7 Fax LEX IMT IP IP backbone IP IMT LEX Fax Phone Alcatel 7515 Media Gateway Alcatel 7515 Media Gateway Phone 0112_fig3_ed03 figure 3 Alcatel 7515 Media Gateway in a Toll Bypass Application 1.5.2 Competitive Access Providers: VoIP for Broadband Access The Alcatel 7515 Media Gateway helps service providers competing with incumbents by offering broadband network access using Digital Subscriber Line (DSL), Wireless Local Loop (WLL), or cable as alternative access technologies. The largest deployment is expected to be in emerging regions of the world, especially for Small Office Home Office (SOHO) and Small Medium Enterprise (SME) environments. Competitive access providers can capitalize on their investment in broadband network and access infrastructure by offering telephony services on top of data services. Broadband access to residential and corporate users delivers advanced data services. Telephony is still the biggest revenue stream in most markets, and, as a narrowband service, it can be provided at minimal cost over an existing broadband data infrastructure using VoIP technology. Competitive access providers can offer superior VoIP services at more attractive tariff rates to residential customers who already have lifeline telephony service provided by incumbent service providers. In addition to delivering data services, access providers can offer derived services over the broadband data infrastructure. With an IP based broadband network, service providers can offer traditional telephony services in combination with multi media - 17 -
services and inter-working services. IP based voice and data networks also open opportunities to provide enhanced services such as video conferencing, as well as e business applications (for example, web augmented contact centers). The Alcatel 7515 Media Gateway benefits for VoIP for the broadband access application are: Superior scalability with up to DS3 level capacity Interoperability with softswitches, IP phones, and Integrated Access Devices (IADs). The Alcatel 7515 Media Gateway supports standard protocols, and interworks with softswitches and IP terminals to offer advanced VoIP services to broadband subscribers. Calls that originate from a broadband subscriber or an H.323 terminal can be terminated, using the Alcatel 7515 Media Gateway, on the PSTN, see Figure 4. SoftSwitch ISUP/SS7 Megaco/H.248 SS7 H 323 PSTN IMT IP Alcatel 7515 Media Gateway IP backbone IP Fax IAD Phone 0113_fig4_ed03 figure 4 Alcatel 7515 Media Gateway Supporting VoIP Broadband Applications When a broadband subscriber dials a remote PSTN user, the IAD identifies the dialed digits and forwards them to the softswitch. Using the Megaco protocol, the softswitch identifies the IP address of the Alcatel 7515 Media Gateway based on the called number. The Alcatel 7515 Media Gateway receives the broadband call and passes it to the PSTN. - 18 -
2 Architecture and Hardware This chapter provides information concerning the Alcatel 7515 Media Gateway architecture and hardware. The following sections are presented: Introduction Architecture System Components Power Supplies Clock Cards Alarm Cards Fan Trays Alcatel 7515 Media Gateway Modules Alcatel 7515 Media Gateway Configurations High Availability Diagnostics. - 19 -
2.1 Introduction 2.2 Architecture The Alcatel 7515 Media Gateway is a low-density media gateway which deliver high availability and carrier grade quality transmission with redundant service processing modules, power supplies, fans, external synchronous clocks and packet interfaces. The Alcatel 7515 Media Gateway can offer the flexible interfaces to the STDM/packet networks, and the independence of the key modules facilitates the upgrade of the Alcatel 7515 Media Gateway to protect the customer s investment. The Alcatel 7515 Media Gateway embraces a modular architecture, which uses an open, programmable call control model. Call processing is independent of other functions, such as resource management, routing, or forwarding. MainBoard SCM CPM VPM (PM-UMS-xxx) PPM RTM Figure 5 A7515 Non-Redundancy System Architecture Overview The Alcatel 7515 integrates the basic common modules such as the circuit processing module, packet processing module and system control module into a single main-board, but separates the key modules - the voice processing module and rear transition module from the main-board to facilitate the upgrade, shown as figure 5. - 20 -
2.2.1 Software Modules Figure 6 shows the software modules in the Alcatel 7515 Media Gateway. Media Gateway Applications Gateway Control Protocols (GCP): H.248/MEGACOP Connection Handler & Resource Management... Signaling Gateway Applications SIGTRAN xua Protocols Telnet User Interface Fault Tolerant Application Manager Platform Applications (OAM&P) SNMP Diagnostics TFTP Alb rec ht Sc hw arz (15 -D ec- 20 01) TDM Manager Resource Manager Voice Port Manager APS Data Management File System Physical Device Manager Configuration Data Base Manager Redundancy Manager Inte Soc Local Access UDP TCP SCTP Communication Pl at fo r m C or e Multicast Manager Logical Port IF (LPI) Port IF (PIF) MARP Function ARP Function ARP Table IP Management Interface IP Forwarder High Speed IP Forwarder IP Cache Table IP Forwarding Table IP Routing protocols & RIB RIP OSPF Kernel Protocol Demux GFI Generic Forwarding Interface (GFI) HdS Driver Driver TTY Driver Flash File Figure 6 Software Modules in an Alcatel 7515 Media Gateway Table 7 describes the functionality of the Alcatel 7515 Media Gateway s primary software components. Table 7 Alcatel 7515 Media Gateway Software Gateway Control Application Software Module Functions Function The Gateway Control Application enables call processing and seamless interworking with the softswitch using either the Megaco or MGCP protocol. - 21 -
TDM Manager Resource Manager and Voice Channel Control Voice Port Fault Tolerant Application Management Software Configuration Database Manager (CDBM) Routing Server/Packet Forwarding The TDM manager is responsible for the setup and teardown of TDM connections (DS0 paths 64 kbit/s). It also arranges the allocation of DSP resources for the requested channels. The Resource Manager and Voice Channel Control software allocates and releases DSP resources for voice channels. Resource managers stored in each DSP module track the status and availability of all DSPs. When a dedicated line is configured, or when a switched call comes in, a request is broadcast to each of the DSP modules. Resource managers throughout the system receive the request and determine the resources that are needed to set up a TDM circuit from the input port to the pooled DSP resources. The Voice Port software configures and manages DSP resources that have already been allocated by the resource manager. The FTAM monitors the Alcatel 7515 Media Gateway software components to ensure non stop operation. The FTAM controls system start up, sense hardware status, and measure internal temperatures. The CDBM collects, distributes, and stores configuration information for the entire chassis. The routing and packet forwarding server forwards IP packets based on module cache memory and forwarding tables. 2.2.2 Central Forwarding The Alcatel 7515 Media Gateway uses a high performance forwarding engine to do the packet forwarding, this can lighten the processing pressure of the voice processing module. Meanwhile, the high performance forwarding engine minimums the packet delay in the media gateway. IP forwarding uses the forwarding table, which maintains same information as master routing table, and ARP table to make forwarding decisions. At the same time, IP caching will be used based on source, destination pairs for higher performance. All management packets addressed to system itself (TCP/UDP/OSPF packets etc.) will be handled over to IP Local Stack subsystem. The forwarding table will keep synchronization with master routing table. Any change of the master routing table will be updated to forwarding table after a fixed interval. - 22 -
Master Routing Table IP Cache Note: the Forwarding Table maintains the same information as the master routing table ARP Table Ethernet IP Interface Figure 7 Central IP Forwarding 2.2.3 Voice Processing 2.3 System Components The Voice Processing Module is an independent daughter board Mounted on the main-board to facilitate the upgrade of the A7515. The Alcatel 7515 Media Gateway is constructed according to an efficient, modular, pooled DSP resource design. The DSPs offer G.711 G.729a and G723.1 Codecs to any interface to perform voice compression, packetization, silence suppression, echo cancellation, and other packet voice processing services. The Alcatel 7515 Media Gateway system modules/components are as followings: 2 slot shelves with a back-plane Fan tray (side mounted with side venting) Main-board (also Named Front Service-Processing Board) Circuit Processing Module Voice Processing Module (Refer to Section 2.2.3) Packet Processing Module System Control Module - 23 -
Clock module Alarm module Rear Transition Module See Figure 8 which shows the front and rear views of the Alcatel 7515 Media Gateway. The manboards are inserted from the front of the unit, and the RTMs are inserted from the rear of the unit, and the fan trayss are inserted from the rear or front of the unit. All cables are available from the rear of the Alcatel 7515 Media Gateway Viewed from the front or rear, the Alcatel 7515 Media Gateway has -two horizontal slots. The gateway is rack mountable in the following standard equipment racks: 19 inch 23 inch 600 mm. As many as 20 Alcatel 7515 Media Gateway units (in an ETSI/ANSI configuration) can be installed in a single 2,20 meter (standard 7 foot) equipment rack. Figure 8 Alcatel 7515 Media Gateway Rear View Figure 9 Alcatel 7515 Media Gateway Front View - 24 -
2.4 Mainboard Modules The Alcatel 7515 media gateway main-board is also named FM-SPM-C5 Board. The main-board comprises several modules: System Control Module Circuit Processing Module Packet Processing Module Alarm Module Clock Module 2.4.1 System Control Module (SCM) The System Control Module performs configuration services and route calculation for the Alcatel 7515 Media Gateway. It is a special module containing additional memory, flash Programmable Read Only Memory (PROM), and boot PROMs. While all Alcatel 7515 Media Gateway modules forward packets, the System Control Module additionally runs Megaco or MGCP signaling protocols and provides a primary point of control for network management; it maintains a master copy of all operating software that is downloaded to other modules as well. When the Alcatel 7515 Media Gateway is configured into 1+1 redundancy, two System Control Modules exist in a system: one is active, and the other remains in the hot standby mode to automatically assume all primary System Control Module functions if the active module should fail. Primary and secondary System Control Modules are configured during system power up. Table 8 contains System Control Module more details. Table 8 System Control Module Performance CPU Type 2.4.2 Circuit Processing Module System Control Module Details Description 2 Dhrystone MIPS/MHz 128-Gbps on-chip bus bandwidth, 26-Gbps memory bandwidth, up to 29-Gbps total I/O bandwidth MIPS64 600~1000 MHz The circuit processing module comprises one sub-modules: one is T1/E1 module. The T1/E1 sub-module provides the T1/E1 PSTN interface function for an Alcatel 7515 Media Gateway in the ANSI/ETSI configuration. This sub-module implements complete support for up to 16 T1/E1 interfaces. Table 9 lists the main-board characteristics equipped with the T1/E1 interface. - 25 -
Table 9 WAN Line Interface Module Part Number Performance Interfaces per module Hot Swappable Main-board with T1/E1 Interface Description FSB IP/ATM 8/16E1 8/16 T1/E1s, each at 1.544/2.048 Mbit/s (8 x 24/30 =192/240 DS0s or 16 x 24/30 =384/480 DS0s) 8/16 E1s, using RJ45 Connectors Yes Operating Temperature 0 ºC to 40 ºC Operating Humidity CPU Type Framing Support Line Encoding Support 0 80 % (non condensing) MIPS64 600~1000 MHz E1: Double- & CRC Multi-frame T1: F4, D4, ESF, SLC96 E1: HDB3 Standards Compliance G.703 AMI/T1: B8ZS AMI with ZCS G.704 G.705 G.706 G.732 G.735 G.736 G.737 Several key T1/E1 Interface module parameters can be configured using CLI commands to further define the characteristics of an T1/E1 interface. The following options are supported in the Alcatel 7515 Media Gateway: Framing Type: ITU T G.704 Framed Mode Line Code: HDB3 Integrated Channel Select Unit (CSU), configurable for short or long haul external CSU support from 0 to 199 meters (0 to 655 feet). 24 hour statistics/status history buffer selectable for viewing in 15 minute timeframes (framing errors, Cyclic Redundancy Check (CRC) errors, line coding violations, pulse density violations, etc.). - 26 -
2.4.3 Packet Processing Module Packet Processing Module consists of two sub-modules: Packet Interface Module (PIM) and Packet Switch Fabric (PSF). Packet Interface Module provides line/trunk interfaces for packet-switched networks, protocol processing functions for the used packet bearer and meta-bearer protocols, and packet forwarding. The types of packet ports are 1+1 Fast Ethernet (electric), or 1 Gigabit Ethernet (electric), or 1+1 Gigabit Ethernet (Optics). All external interface connectors are implemented in the RTM. The PIM provides as well local packet switching capability for data path packets. PSF Provides packet internal switching functionality, and cascaded interfaces and network manage interface are implemented in this sub-module. Table 10 lists the PPM characteristics Table 10 Packet Processing Module characteristics Item Main board Part Number RTM Part Number Performance Interface Type Hot Swappable Description FSB IP/ATM xxx RTM-FE RTM-eGE RTM-oGE RTM-ATM(future) Over 4,500 MIPS 40M PPS (standard IPv4 L3 look-up/switching) 1+1 Fast Ethernet (electric) 1 Gigabit Ethernet (electric) 1+1 Gigabit Ethernet (Optics) Yes Operating Temperature 0 ºC to 40 ºC Operating Humidity CPU Type 0 80 % (non condensing) NPU 266MHz Standards Compliance IEEE 802.3 2.4.4 Alarm Module - 27 -
2.4.5 Clock Module In the Alcatel 7515 Media Gateway, the clock module is integrated into the main boards, and it is a centralized duplicated clock generation and distribution system. The clock module contains internal clocks, alarm relay contacts, and an administrator terminal access. The clock module includes an 8 khz clock to accomplish local line timing configuration. The clock module in the master main board work on master mode, and the one in the slave main board works on slave mode. 2.4.6 Power Supplies A single Alcatel 7515 Media Gateway is a self-contained cabinet, and the mainboards, the rear boards, and the fan-trays have their own power supply and distribution, their source being the globally distributed -48V DC Central Office power supply. Hence, own power supply and own converter for each board and RTM, i.e., no power dependency between the main-boards and/or the RTM boards except the voice processing daughter board is depending on the main-board. Two -48V DC power supplies are connected to a Alcatel 7515 Media Gateway for the redundancy: if one power supply fails during operation, the boards will automatic switch to power supply. - 28 -
2.5 Rear Transition Module All external interface connectors are implemented in the rear transition module. These interfaces include: 8 T1/E1 connectors each RTM, and two RTMs are required if 16 T1/E1 is configured 1 10/100Mbit Ethernet connector each RTM for WAN data link 1 SSU/BITS connector each RTM 1 10/100Mbit Ethernet connector each RTM for network management 1 RJ-45 connector each RTM for craft (RS232) 1 RJ-45 connector each RTM for alarm RTM only directs the external link to the main board through back plane. 2.6 Fan Trays Hot swappable fan trays are used to cool the Alcatel 7515 Media Gateway shelves. If an individual fan fails, an alarm is sent to the network management software.there are two types of fan trays: one is inserted from the front with three fans, and the other is inserted from the rear with one fans. In a fully loaded system, two front fan trays and one rear fan trays are required. Exhaust airflow is directed from the left to the right of the shelf from the front view - 29 -
2.7 Voice/Fax Processing Modules voice/fax processing modules consist of the industry leading DSP chipsets,which provide a complete solution for transporting multiple media types between circuit-switched and packet-based networks. These DSPs are ideally suited for the converging voice and data network infrastructure. For the A7515 product, the modules address requirements such as Voice and Fax over packet, while maintaining support for traditional PSTN Data/Fax applications. The PM-VPM-240/480 modules serve up to 240/480 connections simultaneously. Table 12 lists PM-VPM-480 details. Table 12 PM-VPM-480 Module Details Universal Server Module Description Part Number PM-VPM-480 Performance 480 G.711 Channels (at 64 kbit/s) 200 G.729a/b Channels (at 8 kbit/s) 160 G.723.1 Channels (at 6.3 kbit/s) 120 FoIP Channels Interface to motherboard PT2MC Operating Temperature 0 ºC to 40 ºC Operating Humidity 0 80 % (non condensing) Power Dissipation 10w@3.3v Clock Frequencies 33 MHz PCI Bus 50 MHz for RMII bus 8.192MHZ for CT bus Standards Compliance G.711 G.729a/b G.723.1 T.38 Voice/Fax Processing Module Features The voice/fax processing module is based on industry leading DSP technology, offering advanced VoIP and FoIP processing capabilities. A multi-service access chipset is implemented in this module. This chipset supports flash upgrades of new feature implementations and enhancements without requiring hardware changes. - 30 -
Voice Features The following voice features are supported in Voice/fax Processing modules: G.711 without silence suppression G.711 with silence suppression: Voice Activity Detection (VAD), and Comfort Noise Generation (CNG) Configurable voice packet frame size Configurable Jitter Buffer, up to 200ms G.711 u law and a law encoding G.729a, 8 kbit/s VAD, CNG G.729b G.723.1, 6.3 kbit/s Dynamic Codec switch Fax Features G.168 echo cancellation with up to 128 ms tail length. The following facsimile features are supported in Voice/fax Processing modules: Automatic Fax detection Automatic voice/fax/data/ codec switchover Automatic echo cancellation and silence suppression turned off for fax calls G.711 transparent pass through FAX relay. T38 Real-time Fax over IP 2.8 Alcatel 7515 Media Gateway Configurations Each front slot in the Alcatel 7515 Media Gateway accommodates a mainboard that provides protocol processing, packet forwarding, system control and management, and server functionality. Each rear slot accommodates a RTM board that provides various combinations of line interfaces. The voice processing daughter board mounted on the front mainboard is responsible for processing voice packets bridging PSTN network and packet network, refer to figure 2-1. Table 13 summarizes the VoIP functionality processed by each of the Alcatel 7515 Media Gateway modules. Table 13 VoIP Functionality VoIP Functions Processed by the Modules System Control Packet Processing Circuit Processing Voice Processing - 31 -
Overall System Initialization and Management Call Control and Connection Management Routing and Forwarding Packet Handling TDM Hairpinning PSTN Interface Packet Interface Voice Processing, Coding, and Packetization Silence Suppression, Comfort Noise Generation, and Echo Cancellation Management Interface Module Module Module Module X X X X X x x X x x X If no redundancy is required, one mainboard with one voice processing module, and one RTM(8 T1/E1s) or two RTMs (16 T1/E1s) is equipped in a Alcatel 7515 media gateway. If the redundancy is required, two mainboards with one voice processing module each, and one RTM(8 T1/E1s) or two RTMs (16 T1/E1s) is equipped. Table 14 shows the board configuration for each case. Table 14 The board configuration Non-Redundancy Redundancy Board 8 T1/E1 16 T1/E1 8 T1/E1 16 T1/E1 FSB Mainboard 1 1 2 2 VPM daughter Board 1 1 2 2 RTM 1 2 2 2-32 -
ETSI The ETSI configuration characteristics are: Eight/Sixteen E1 trunks, connected to the PSTN Ethernet Ports: 1+1 10/100 Base-T, fully protected, connected to the IP Network 240/480 VoIP Ports ANSI 4800/9600 Busy Hour Calls. 2.9 High Availability The ANSI configuration characteristics are: Eight/Sixteen T1 trunks, connected to the PSTN Ethernet Ports: 1+1 10/100 Base-T, fully protected, connected to the IP Network 192/384 VoIP Ports for T1 3840/7680 Busy Hour Calls For T1. The Alcatel 7515 Media Gateway offers exceptional availability to address the stringent requirements for Central Office deployments. High availability begins with redundant system buses and extensive redundant hardware. Every essential hardware and software component can be backed up by at least one redundant copy. Hardware components are hot swappable, including mainboard, fans, and power supplies. The internal FTAM software detects internal and external outages, and restores service automatically when possible. 2.10 Diagnostics The following list contains diagnostic features supported by the Alcatel 7515 Media Gateway. SYSLOG on remote host (UNIX and Windows platforms) Support for eight SYSLOG message levels Secondary/backup log server support Call trace features Startup diagnostics tests On demand diagnostic tests. - 33 -