1 Xpress2500 Access System The Industry s First Single-Pair Multirate Symmetric DSL Access System Bruce Young Chief Technology Officer Telmax Communications Corporation Telmax Communications 1998
2 Telmax Xpress2500 MSDSL Access System Executive Summary Today s bandwidth-hungry applications such as Internet access, remote LAN access, teleconferencing, workgroup and data sharing, telecommuting and numerous varieties of digital video services are driving today s demand for high-speed data network access. Network Service Providers (NSPs), including Regional Bell Operating Companies (RBOCs), Competitive Local Exchange Carriers (CLECs), Internet Service Providers (ISPs), and independent telephone companies, are looking for ways to expeditiously and economically provide this high-speed access to their customers. Telmax Communications Corporation designs, develops and markets transmission systems based on Digital Subscriber Line (DSL) technology for copper wire plant. They support all contemporary data rates, from 64 kbps to multi-megabit symmetric and asymmetric transmission for voice, video and data communications over a single copper pair. Telmax access systems link enterprise LANs and Network Service Providers over private and public networks across the local loop, the connection between the customer and the first network node. Increasing demand for high data rate services makes the copper plant a valuable resource. Telmax Xpress2500 products provide transmission over a single copper pair, more than doubling the transmission capacity of the existing copper plant. Telmax Xpress2500 systems provide full-duplex, T1/E1 and fractional data rates (up to 2.304 Mbps) over a single pair of wires exceeding 14,000 feet over 26 AWG. Xpress2500 products replace older four-wire T1/E1 and fractional T1/E1 technology with state of the art technology providing both cost-effective and extended reach (beyond 18,000 feet with mixed gauge wire) benefits. The Xpress2500 access system provides multiple interface options at both the central office and the customer premises. Interfaces include: T1/FT1, E1/FE1, V.35, Ethernet learning bridge and an integrated IP/IPX router supporting Frame Relay access.
3 The Xpress2500 access system provides repeaterless transport of up to 2.304 Mbps, at various DSO rates, over a single pair of unconditioned copper wire. The rate is automatically adjusted to synchronize at the highest of 10 specified rates, corresponding to the distance between the local and remote units (see chart below). Alternatively, the data rate is software selectable at any of the available NxDS0 rates (see chart below). REACH in feet (km) Data Rate No Noise 49 Self-Next - Worst case DSO s Kbps 26AWG (0.4mm) 24AWG (0.5mm) 26AWG (.04mm) 24AWG (.5mm) 2 128 21,400 (6.5) 29,100 (8.8) 17,500 (5.3) 25,700 (7.8) 4 256 20,300 (6.2) 27,500 (8.3) 15,300 (4.6) 22,300 (6.7) 6 384 19,000 (5.8) 26,300 (8.0) 13,800 (4.2) 20,400 (6.2) 8 512 18,000 (5.5) 25,200 (7.7) 12,500 (3.8) 18,300 (5.6) 12 768 16,500 (5.0) 22,500 (6.9) 11,300 (3.4) 15,400 (4.7) 16 1,024 16,000 (4.9) 21,900 (6.4) 10,600 (3.2) 14,600 (4.5) 24 1,536 14,000 (4.3) 19,200 (5.8) 9,100 (2.8) 12,500 (3.8) - (T1) 1,544 14,000 (4.3) 19,200 (5.8) 9,100 (2.8) 12,500 (3.8) 32 (E1) 2,048 12,000 (3.7) 16,000 (4.9) 7,900 (2.4) 10,500 (3.2) 36 2,304 11,500 (3.5) 15,300 (4.6) 7,700 (2.25) 9,800 (3.0) Xpress2500 Rate vs. Reach Operating at T1 speed, clean loops may be at distances over 14,000 feet using 26 AWG (0.4 mm). Loops may be used without removing bridged taps or requiring binder group separation. All Xpress products incorporate Telmax two-wire copper technology, including high data rates, pre-provisioning, safety standards, service features and digital interfaces. Additional key Xpress2500 features are: T1/FT1 (DSX-1), E1/FE1 (G.703), V.35 and Ethernet Learning Bridge standard interfaces Integrated IP/IPX router maps all layer 3 protocols into on Ethernet remote bridge Ethernet interface with integral FRAD supports Frame Relay over T1 Integral CSU/DSU functionality Mixed CO/CPE interfaces with individual cabling Common network management AT&T SLC 220 mechanics with 20 interface cards per 23-inch shelf Performance monitoring for early warning Alarm, alert, local and remote notification Embedded SNMP agents FCC Part 15 Class B, UL, CSA Distributed power makes all cards independent Hot swap and auto-attendant capability for each module Subscriber line conditioning and problem isolation ETSI Standard compliant
4 The Xpress2500 MSDSL Access System I. OVERVIEW The Xpress2500 MSDSL access system provides high-speed data access over single-pair copper wiring. The Xpress2500 system consists of the XpressCentral220 central office shelf, Xpress2500 line interface cards and the WebXpress2500 remote branch office modem. Telmax Xpress2500 access system provides industry-standard Fractional T1 and T1 (DSX-1), Fractional E1 and E1 (G.703), V.35, Ethernet learning bridge, IP/IPX router and FRAD Frame Relay interfaces. Telmax two-wire T1 reach exceeds 14,000 over 26 AWG (clean loop). With industry standard interfaces, each system immediately replaces older four-wire technology in existing systems to recover half of the existing copper cable and reduce repeater deployment costs. The Xpress2500 access system is packaged for campus and for Telco environments. Both environments can use any of the supplied standard interface options. For the campus environment, Xpress2500 system maps corporate LANs and individual users to company networks and to Network Service Providers (NSPs) at T1/ FT1, E1/FE1, and faster rates. Telmax provides a wide range of symmetric transmission products. They support a variety of communications services utilizing MSDSL technologies and all industry standards interfaces. The Xpress2500 system includes fast transmission products for a single wire pair at T1/E1 and fractional rates. In summary, the Xpress2500 is a physical layer MSDSL transmission system for single-pair copper wire plant supporting standard interfaces at flexible data rates, from 128 kbps to 2.034 Mbps symmetric transmission for voice, video and data communications. II. BANDWIDTH ISSUES During the 1980s, ANSI standardized the four-wire T1 reach at 3,000 feet, before repeating, over mixed-gauge copper wire. The T1 was repeated at 6,000 foot hops over mixed-gauge wire. However, contemporary AT&T SLC 2000 T1 reach remains 3,000 feet. During the early 1990s, High-bit-rate Digital Subscriber Line (HDSL) technology improved the
T1 reach to 9,000 feet over four wires (two copper pairs). 5 Then in June of 1997, Telmax Communications provided the first single-pair T1 system, the Xpress2300. The Xpress2300 system exceeds 12,000 feet over a single 26 AWG wire pair. To optimize conventional regulated T1 services, Telmax developed the Xpress2500 central office line interface module and customer premises WebXpress2500 MSDSL modem to exceed the 12 thousand foot CSA requirement. When the Xpress2500 system is configured with conventional DSX-1 interfaces, it provides T1 services at 14,000 feet over a single 26-gauge wire pair while, at the same time, lowering the cost of deployment. For newer applications, Telmax provides variable data rates over a single 26-gauge wire pair, from 128 kbps to 2,304 kbps all at extended reaches, including 20,000 ft. at 384 kbps. Flexible delivery of data bandwidth provides the service providers with options to control customer usage, overbooking, reporting, immediaty tailored throughput on demand to synchronous Ethernet, IP, IPX and Frame Relay systems. Other interface options deliver raw unclocked data exceeding to up to 2.304 Mbps, suitable for MPEG quality video. Product variations are presented in following sections. III. CO-LOCATED SERVICES Telmax Xpress2500 line cards fit the Telmax XpressCentral220 high density AT&T SLC 220 mechanics chassis. Telmax XpressCentral220 chassis holds 20 line cards and one network management module. Telmax XpressCentral 220 chassis provides 43% increased density over conventional SLC 220 mechanics. Telmax XpressCentral220 chassis and line cards can be co-located within a central office or substation or in hardened enclosures. The XpressCentral220 chassis requires only -48 VDC input. Xpress2500 line cards feature distributed power. Each line card derives all its power requirements from the single -48 VDC input. A single card failure does not affect any of the other services resident in the XpressCentral220 chassis and all line cards are hot swappable.
6 IV. ARCHITECTURE Xpress2500 line interface cards and WebXpress2500 are built with a common modular architecture. The modular architecture improves product quality by using the same test and qualifications of modules and systems. Interface Connector Interface Module Main Board Data Pump Module Front Panel Figure 4.1 WebXpress2500 Architecture The Xpress2500 MSDSL access system provides a wide variety of WAN interfaces, with software selectable symmetrical transmission rates from 128 kbps to 2.304 Mbps. The WebXpress2500 accepts any of the following interface modules; DSX-1 (T1), G.703 (E1), V.35, Ethernet Learning Bridge, and Ethernet with an integrated IP/IPX router and Frame Relay support. Table 4.2, Xpress2500 Interface Compatibility Chart Plug-in interface modules may be added to the Xpress2500 systems as a customer field upgrade. Software upgrades may be performed through the Xpress2500 to both the Xpress2500 and to the WebXpress2500 or may be performed locally at the WebXpress2500 with any personal computer. Software upgrade requirements are: IBM compatible PC with a DOS prompt (or DOS, Windows 95) and one 3.5-inch floppy drive. Most of the interface modules may be applied to either side of the Xpress2500 system. Some can be mixed and matched. For example, the WebXpress2500 accepts a V.35 interface module and can communicate with an Xpress2500 line card configured with the DSX-1 interface module.
7 The following sections show some of the many configurations possible with Xpress2500 MSDSL access system. V. APPLICATIONS Telmax Xpress2500 offers most industry standard interface options to customers. The interface options help service providers target customer applications, such as synchronous T1/E1 Fractional T1/E1, frame relay, and Ethernet Learning Bridge or IP/IPX router with frame relay support. In regulated environments, these products quickly solve the challenges of connecting many subscribers at high data rates. In unregulated environments, these products economically and expeditiously bring Internet, Intranet and other new services to campus, Telco and ISP markets. The following examples illustrate the variety of applications served by the Xpress2500 MSDSL access system. These configurations are but a sampling of the many combinations of interface modules placed in both the XpressCentral220 shelf and WebXpress2500 equipment. Xpress2500 access system interface options are continually being added and enhanced in order to provide high-speed WAN access to all telecommunications and data communications environments. Far Reach Single Pair T1 The Xpress2500 T1 (DSX-1) and E1 (G.703) interfaces replace a four-wire transmission system with two wires, effectively doubling the utilization of the copper loop while extending the reach from below 9,000 feet to beyond 14,000 feet. A configuration is shown in figure 5.1. Switch Central Office Shelf Xpress CO/POP WEBX T1 PBX WEBX T1 MUX Voice Data (Nx64) (Nx64) Figure 5.1 Xpress2500 T1/E1 replaces four-wire with two-wire systems
8 The T1 (DSX-1) interface provides standard 1.544 Mbps data rate wherever T1 service is deployed or planned and the E1 (G.703) interface provides the standard 2.048 Mbps data rate for E1 service. High-speed Synchronous Interfaces The WebXpress2500 V.35 high-speed synchronous interface facilitates new applications such as teleconferencing and telecommuting. Current V.35 high-speed options include internally clocked 128 kbps to 2.304 Mbps and externally clocked T1 (1.544 Mbps) and E1 (2.048 Mbps) rates. The V.35 interface can be mixed with T1 (DSX-1) or with E1 (G.703) interfaces for endto-end transmission. Switch Central Office Shelf Xpress CO/POP Single Pair 24 AWG 384 kbps 20,000 Ft Local Loop with noise WEBX V.35 Router LAN Customer Premises Figure 5.2 Xpress2500 V.35 at 2.048 Mbps Typical applications include MPEG quality video, videoconferencing, telecommuting and fast file transfer.
9 Selectable Data Rate Synchronous Interface The WebXpress2500 V.35 interface allows reach/rate adjusted or at 10 DSO increments. This application provides rate structures selectable by agreement between the service provider and each customer. Appropriate applications include programmable frame relay, channelized T1/E1 or Fractional T1/E1 service to PBX, bandwidth-on-demand for teleconferencing, remote learning, and Internet access. Packet Interfaces; Ethernet Learning Bridge The 10BaseT Ethernet interface is provided via an RJ48 connector. Ethernet access is provided as a remote Ethernet learning bridge (standard 802.1d). A single workstation can directly connect the WebXpress2500 Ethernet port to a personal computer. Alternately, the WebXpress2500 Ethernet interface port can be used to connect multiple LAN users to the network, as shown in figure 5.3. Switch Central Office Shelf CO/POP T1/E1 Xpress2500 Single WebXpress2500 (10BaseT Bridge) Pair Single Pair 128 kbps to 2.304 Mbps WEBX 10BaseT Copper LAN Figure 5.3 LAN access with a WebXpress2500 remote Ethernet learning bridge
10 Applications for remote Ethernet connectivity are as numerous as the use of business systems and as ubiquitous as the prevalence of LAN environments. Examples include, Internet Service Providers, corporate campus networks, remote computing and video services. Packet Interfaces; Ethernet with IP/IPX router and Frame Relay access The WebXpress2500-RTR is the industry s first MSDSL access device to provide integrated CSU/ DSU IP/IPX router and FRAD to support PPP and Frame Relay protocols at T1/E1 rates over a single copper pair. WebXpress2500-RTR provides one Ethernet 10BaseT connection and one serial WAN port. All other LAN protocols are bridged, with built-in Spanning Tree Protocol. Switch CO/POP T1/E1 Central Office Shelf Xpress2500 Single Frame Relay or PPP Pair Copper Single Pair 128 kbps to 2.304 Mbps WEBX WebXpress2500 (with integral IP/IPX Router and FRAD) 10BaseT LAN Figure 5.4 Frame Relay Support via Integrated IP/IPX Router
11 VI. ADDITIONAL XPRESS2500 ACCESS SYSTEM FUNCTIONALITY Power-up Diagnostics Each Xpress2500 product provides automatic start-up with automatic power-on self test (POST). Status and alarm reporting is also automatic via alarms and SNMP, allowing the Xpress2500 and WebXpress2500 products to run completely unattended. Operating Diagnostics The WebXpress2500 provides smart jack isolation, loopback, cable open, short and synch status. These diagnostics are transferred from the WebXpress2500 to the corresponding Xpress2500. Smart jack diagnostics assists installation and customer support for quick fault isolation and problem resolution. Automatic Wire Loop Detection A service technician installing Xpress2500 equipment does not need to know the polarity of the central office inputs, the digital loop outputs, or the customer premises wiring. Either wire of the pair may be connected to either pole. VII. NETWORK MANAGEMENT WebXpress2500 is configured and managed locally via a 2x16 character LCD display and membrane switches on the front panel or via a PC running Windows 95 connected to the unit through the console port on the rear panel. It can also be configured and managed remotely via a PC connected to the corresponding Xpress2500 or WebXpress2500 or through the Network Management Module (XpressNMM) housed in the XpressCentral220 shelf. The Xpress2500 line cards are configured and monitored via a PC connected through a front panel console port or through the XpressNMM. Embedded SNMP XpressNMM supports Simple Network Management Protocol network management platform. For SNMP, the NMM supports SNMP Managed Information Base (MIB) I, MIB II and Telmax enterprise MIB standards. The Xpress2500 and WebXpress2500 enterprise MIB is periodically expanded to include more manageable objects.
12 All Xpress2500 products in a shelf, and their corresponding remote units, report to and are managed via the optional Xpress NMM housed in the XpressCentral220 chassis. The NMM line card provides two management ports: Ethernet RJ48 and RS232 RJ45 COM port. The XpressCentral220 chassis is completely manageable from any connected LAN station. The station requirements are flexible, supporting most popular graphical management platforms, including HP OpenView and SNMPc. Similarly, the RS232 COMport supports direct PC connection. The PC requirements are simple: a DOS command prompt and one 3.5-inch floppy disk drive. VIII. SUMMARY Telmax provides symmetric and asymmetric MSDSL access systems tailored for environments supporting a variety of communications. The single-pair Xpress2500 access system provides high-speed transmission over a single wire pair supporting rate/reach adjusted or programable data rates from 128 kbps up to 2.304 Mbps. Additional Telmax functionality included in the Xpress product family includes: Replaces high-speed, four-wire networks with two-wire systems Multiple industry standard interfaces for all commercial and residential applications, Real-time data rate adjustment, allocation and monitoring, Automatic line polarity connection and safety features, Subscriber line condition and problem isolation, Hot swap and auto-attendant capability for each unit, Reliable distributed power to all units, Supports SNMP and TL1 network management platforms. Telmax remains committed to providing state-of-the-art, single-pair copper MSDSL access systems today.