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Megabit Modem CRA-C User Manual Powe r 1 0 B A S E - T A D S L Manual Number: 425-613-150-02[...]

ii Megabit Modem CRA-C User Manual Megabit Modem CRA-C User Manual P/N 425-613-150-02 Revision 02 May 1998 Copyright © 1998. PairGain Technologies, Inc. All rights reserved. This document contains proprietary information which is protected by copyright. Information contained in this document is company private to PairGain Technologies, Inc. and sh[...]

Megabit Modem CRA-C User Manual iii FCC NOTICE This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment gener[...]

iv Megabit Modem CRA-C User Manual DECLARATION OF CONFORMITY Manufacturer’s name PairGain Technologies, Inc. and address: 14402 Franklin Ave Tustin, CA 92780-7013 U.S.A. declares that Product name: Megabit Modem CRA-C conforms to the following Standards: EN55022 (1987), EN50082-1 (1992), EN60950 (1994) Application of Council Directives: 89/336/EE[...]

Megabit Modem CRA-C User Manual v USING THIS MANUAL This manual helps you: • understand the features of the PairGain ® Megabit Modem™ CRA-C and how the unit operates as a component within a network • install the Megabit Modem CRA-C • configure your unit to operate within the network • contact PairGain if you need additional help Three ty[...]

Using This Manual vi Megabit Modem CRA-C User Manual[...]

Megabit Modem CRA-C User Manual vii CONTENTS ABOUT THE MEGABIT MODEM CRA-C __________________ 1 About Rate Adaptive Transmission ..................................... 2 Rate Adaptation .............................................................. 2 Reach, Data Rate, SNR Margin, and Noise Environment............................................ 4 IN[...]

Contents viii Megabit Modem CRA-C User Manual NETWORK AND MANAGEMENT OVERVIEW ____________ 51 MAC Layer Bridging and Spanning Tree Protocol ............ 51 Static IP Routing ............................................................... 5 3 Megabit Modem CRA-C IP Addresses .......................... 59 Management Protocols ........................[...]

Megabit Modem CRA-C User Manual 1 ABOUT THE MEGABIT MODEM CRA-C The PairGain ® Megabit Modem™ CRA-C uses Asymmetric Digital Subscriber Line (ADSL) technology to provide, on a single pair telephone line, a multi-megabit Ethernet connection between the subscriber and the service provider. The Megabit Modem CRA-C transmits data up to 3.16 Mbps from[...]

About the Megabit Modem CRA-C 2 Megabit Modem CRA-C User Manual Use the Megabit Modem CRA-C with these other PairGain products: • Megabit Modem CRA (at subscriber site) • S1 Network Interface Device (network interface at subscriber site) About Rate Adaptive Transmission The following definitions are useful for understanding the operation of the[...]

About the Megabit Modem CRA-C Megabit Modem CRA-C User Manual 3 The Megabit Modem CRA-C can be set to any one of three modes that determine how the data rate is selected. It is important to note that rate adaptation occurs only during startup. The Megabit Modem CRA-C will not change its data rate while the link is up. The three startup modes are: ?[...]

About the Megabit Modem CRA-C 4 Megabit Modem CRA-C User Manual Reach, Data Rate, SNR Margin, and Noise Environment The maximum transmission rate of the Megabit Modem CRA-C is determined by distance, SNR margin, and the condition of the line (wire gauge, condition noise environment). Figure 1 shows the relationship between reach and data rate for a[...]

About the Megabit Modem CRA-C Megabit Modem CRA-C User Manual 5 Figure 1. Reach for a Rate Adaptive ADSL Megabit Modem[...]

About the Megabit Modem CRA-C 6 Megabit Modem CRA-C User Manual[...]

Megabit Modem CRA-C User Manual 7 INSTALL THE MEGABIT MODEM CRA-C Install the Megabit Modem CRA-C using these sections: For information about this topic Go to page Unpack and inspect the shipment 7 Identify LEDs and connectors 9 Install the Megabit Modem CRA-C 12 Power up and check LEDs 16 Unpack and Inspect the Shipment Upon receipt of the equipme[...]

Install the Megabit Modem CRA-C 8 Megabit Modem CRA-C User Manual Table 1. Cables for Megabit Modem CRA-C Item Description Function Straight-through Category 3 cable Black unshielded twisted-pair (UTP) cables terminated with RJ-45 connectors. Connects the Megabit Modem CRA-C Ethernet MDI-X port to a network device with an MDI port. Cross-over Categ[...]

Install the Megabit Modem CRA-C Megabit Modem CRA-C User Manual 9 Identify LEDs and Connectors The Megabit Modem CRA-C front panel has LEDs that show status for power and data transmission. The rear panel has external interface connectors and a power switch. Front Panel Figure 2 and Table 2 describe the LEDs on the Megabit Modem CRA-C front panel. [...]

Install the Megabit Modem CRA-C 10 Megabit Modem CRA-C User Manual Table 2. Front Panel LEDs LED Mode Description Power Green Indicates power is on. 10BASE-T LINK Green Off Ethernet connection up. Ethernet connection down. TX Green Off Transmit activity at port. No transmit activity at port. COL Green Off Collisions occurring on the port. No collis[...]

Install the Megabit Modem CRA-C Megabit Modem CRA-C User Manual 11 Rear Panel Figure 3 and Table 3 describe the Megabit Modem CRA-C rear panel features. Figure 3. Megabit Modem CRA-C Rear Panel Table 3. Rear Panel Components Name Function POWER connector 6-pin mini-DIN type port that supplies power to Megabit Modem CRA-C. Do not connect any other w[...]

Install the Megabit Modem CRA-C 12 Megabit Modem CRA-C User Manual Install the Megabit Modem CRA-C Complete the steps in the order listed to install the Megabit Modem CRA-C: • connect to the ADSL line • connect to the data network Connect to the ADSL Line The Megabit Modem CRA-C requires a single pair of telephone wires to connect the subscribe[...]

Install the Megabit Modem CRA-C Megabit Modem CRA-C User Manual 13 Table 4. ADSL Pin Assignments for RJ-45 Connector Pin Signal 1 Not Used 2 Not Used 3 Not Used 4 ADSL (Ring) 5 ADSL (Tip) 6 Not Used 7 Not Used 8 Not Used Connect to the Data Network The 10BASE-T MDI-X port connects the Megabit Modem CRA-C to the data network. If the data network has[...]

Install the Megabit Modem CRA-C 14 Megabit Modem CRA-C User Manual Figure 5 . Straight-through and Cross-over Cable Pinouts[...]

Install the Megabit Modem CRA-C Megabit Modem CRA-C User Manual 15 Connect to the data network using either the black straight-through cable or the yellow cross-over cable: 1 Plug the RJ-45 connector of the Category 3 cable into the 10BASE-T MDI-X connector on the Megabit Modem CRA-C rear panel (Figure 6). 2 Attach the other end of the Category 3 c[...]

Install the Megabit Modem CRA-C 16 Megabit Modem CRA-C User Manual Power Up and Check LEDs Install the power cable and power up the Megabit Modem CRA-C: 1 Plug the mini-DIN connector on the wall-plug supply into the power connector on the rear of the Megabit Modem CRA-C, then plug the wall-plug supply into the facility power. Do not connect any oth[...]

Megabit Modem CRA-C User Manual 17 CONFIGURE AND VIEW STATUS In this chapter, you configure the Megabit Modem CRA-C or view system status using an ASCII terminal connected to the console port. Go to the following sections: To complete this task Go to page Connect to an ASCII terminal 17 How to log on and navigate the menus 19 How to configure a rem[...]

Configure and View Status 18 Megabit Modem CRA-C User Manual Figure 7. Connecting to an ASCII Terminal 4 Configure these communication settings for the ASCII terminal: • 9600 to 19,200 baud • no parity • 8 data bits • stop bit • flow control to OFF 5 Select ANSI for terminal emulation.[...]

Configure and View Status Megabit Modem CRA-C User Manual 19 How to Log On and Navigate the Menus This section shows you how to log on and then how to navigate the menu structure. Every console screen has a menu header which displays the time in the upper right corner and the date in the upper left corner. Through the menus, you can configure a loc[...]

Configure and View Status 20 Megabit Modem CRA-C User Manual is the factory-default password. If you establish a different password, you must type the new password at the LOGON PASSWORD prompt on a subsequent log on. 2 Type your password at the password prompt or press (factory default password) if you have not customized your password. The Main Me[...]

Configure and View Status Megabit Modem CRA-C User Manual 21 Figure 8 shows the structure for the Megabit Modem CRA-C menus. Type the number of the menu item you want to view or configure. Figure 8. Megabit Modem CRA-C Menu Structure[...]

Configure and View Status 22 Megabit Modem CRA-C User Manual Table 6 shows the ASCII terminal key functions used to navigate the menus and to select settings. Table 6. Keyboard Functions Key Function Restores the p arameter to the last saved settin g . A pp lies to parameters where you type a value but not to parameters you toggle. Goes to Main Men[...]

Configure and View Status Megabit Modem CRA-C User Manual 23 How to Configure a Remote Unit From the Megabit Modem CRA-C, you can view system parameters and set configuration options for the remote Megabit Modem CRA. The remote console menu header reflects the remote unit as ATU-R. This shows that the console program is physically connected to the [...]

Configure and View Status 24 Megabit Modem CRA-C User Manual Configure the System Settings This section describes configurable system settings. You can change factory default settings like time and date, or create a password and unique ID for the unit. 1 On the Main Menu, type to display the System Status and Configuration menu. 07/02/97 PAIRGAIN T[...]

Configure and View Status Megabit Modem CRA-C User Manual 25 3 Do the following for each system setting option you want to change: Type the number of the option you want to configure. Type the appropriate information for each option as indicated in Table 7 then press . Table 7. System Configuration Options T yp e No. For Option Function 1 Change Sy[...]

Configure and View Status 26 Megabit Modem CRA-C User Manual Configure the ADSL Transceiver The ADSL menu provides access to set ADSL configuration parameters and to view ADSL performance and alarm status (menu options 1 through 4). See "View Status" (page 41) for more information on options 1 through 4. Configure parameters for ADSL data[...]

Configure and View Status Megabit Modem CRA-C User Manual 27 2 Do the following for each system setting option you want to change: • Type the number of the option you want to configure. • Select, using the spacebar, or type the appropriate information for each option as indicated in Table 8 then press . 3 After you type or and have made changes[...]

Configure and View Status 28 Megabit Modem CRA-C User Manual Table 8. ADSL Transceiver Options (continued) T yp e No. For Option Function 3* Max Down Data Rate Select a maximum data rate for the downstream channel (from service provider to subscriber). Use the spacebar to scroll through the available rates. 4 Startup SNR Margin Press the spacebar t[...]

Configure and View Status Megabit Modem CRA-C User Manual 29 Reset the ADSL Transceiver When you change any of the options 1 through 4 at the ADSL Menu, Reset the ADSL transceiver to make the changes effective and re-establish the ADSL link. 07/02/97 PAIRGAIN TECHNOLOGIES 08:44:57 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01 ADSL MENU 1. ADSL PERFORMANC[...]

Configure and View Status 30 Megabit Modem CRA-C User Manual Configure the Bridge/Router This section describes how to configure the Ethernet interface (bridge) of the modem as either a bridge or a router. Then, configure the management protocol options through the SNMP Configuration menu. On the Main Menu, type to display the Bridge/Router Menu. 0[...]

Configure and View Status Megabit Modem CRA-C User Manual 31 Configure as a Bridge Configure Bridge parameters at the Bridge/Router Menu. Bridge configuration options are maintained and restored through the system's local service port and are kept in NVRAM to be used in subsequent initializations. 1 Type at the Bridge/Router Menu to display th[...]

Configure and View Status 32 Megabit Modem CRA-C User Manual Table 10. Bridge Configuration T yp e No. For Option Function 2 Local IP Addr Configure for the modem to respond to an application that uses IP protocol including SNMP and TFTP. The default is 0.0.0.0. You can either type in the address supplied by a system administrator or get the IP add[...]

Configure and View Status Megabit Modem CRA-C User Manual 33 Table 10. Bridge Configuration (continued) T yp e No. For Option Function 9 Image File Name Read-only value. This parameter can be configured only in the BOOTP configuration file and is acquired when Boot Mode and Image Load Mode are set to network. This name must match the name of a file[...]

Configure and View Status 34 Megabit Modem CRA-C User Manual Configure as a Router Configure Router parameters at the Bridge/Router Menu. Router configuration options are maintained and restored through the system's local service port and are kept in NVRAM to be used in subsequent initializations. 1 Type at the Bridge/Router Menu to display th[...]

Configure and View Status Megabit Modem CRA-C User Manual 35 The following screen shows configuration for a Megabit Modem CRA (ATU-R) routed toward a Megabit Modem CRA-C (ATU-C), using IP addresses from the example in Figure 12. 07/02/97 PAIRGAIN TECHNOLOGIES 08:54:33 ATU-R ADSL MEGABIT MODEM TERMINAL 01.01 BRIDGE/ROUTING CONFIGURATION MENU -------[...]

Configure and View Status 36 Megabit Modem CRA-C User Manual Table 11. Router Configuration T yp e No. For Option Function 2 Default Contains the address of the default gateway 3 4 5 IP Static Routing Table Consists of the Destination, Subnet Mask, and Gateway. Must be configured for the Megabit Modem CRA-C to operate as a static IP router. 0.0.0.0[...]

Configure and View Status Megabit Modem CRA-C User Manual 37 Table 11. Router Configuration (continued) T yp e No. For Option Function C Image File Name Read-only parameter. The name must match the name of a file on the TFTP server for an image file download to occur. D Image Load Mode S p ecifies how the Ethernet brid g e code is loaded. The Me g [...]

Configure and View Status 38 Megabit Modem CRA-C User Manual Configure SNMP Configure SNMP parameters and trap addresses at the SNMP Configuration menu. 1 Type at the Bridge/Router Menu to display the SNMP Configuration Menu. 07/02/9 7 PAIRGAIN T ECHNOLOGIES 08:53:26 ATU-C ADSL MEGABI T MODEM TERMINAL 01.01 SNMP CONFI GURATION MENU ------- - ------[...]

Configure and View Status Megabit Modem CRA-C User Manual 39 Table 12. SNMP Configuration Options No. For Option Function 1 SNMP Read Only Comm String Provides the authentication string used for SNMP read-only operations. At the prompt NEW COMMUNITY STRING: , type in appropriate community string. Typically, use either Public or Private. The read-on[...]

Configure and View Status 40 Megabit Modem CRA-C User Manual Reset the Ethernet Bridge Changes you make to the Ethernet bridge through the Bridge/Router Configuration menus (pages 31 and 37) and SNMP Configuration menu (page 38) write immediately to flash memory when changes are confirmed. However, they do not take effect until the Megabit Modem CR[...]

Configure and View Status Megabit Modem CRA-C User Manual 41 View Status This section describes status menus. You can view information such as current alarm status, performance history, and product information. See the following section for: system information (page 41) ADSL transceiver status (page 42) Ethernet bridge statistics (page 48) System I[...]

Configure and View Status 42 Megabit Modem CRA-C User Manual ADSL Transceiver Status From the Main Menu, type to display the ADSL Menu. 07/02/97 PAIRGAIN TECHNOLOGIES 08:44:57 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01 AD SL ME NU 1 . A D SL P ERFORMANCE S T ATUS 2. 24 HOUR ADSL PERFORMANCE HISTORY 3. 7 DAY ADSL PERFORMANCE HISTORY 4. AD SL AL AR M H [...]

Configure and View Status Megabit Modem CRA-C User Manual 43 ADSL Performance Status. The ADSL Performance Status screen is updated every second and provides a summary of the ADSL parameters and outstanding ADSL-related alarms. This screen displays the upstream and downstream ADSL links. The SNR (signal-to-noise ratio) margin column displays both t[...]

Configure and View Status 44 Megabit Modem CRA-C User Manual Table 13. ADSL Performance Status Screen Fields Field Meaning Down Alarms Identifies the current alarms in the path to the subscriber. Up Alarms Identifies the current alarms in the path from the subscriber. System State Describes the state of the ADSL system. Startup states: DATA (normal[...]

Configure and View Status Megabit Modem CRA-C User Manual 45 24 Hours ADSL Performance History. The 24 Hour ADSL Performance History report consists of eight screens. Each screen displays three hours of data, providing a 24-hour report in 15-minute increments. Type on the ADSL menu to open the 24 Hour ADSL Performance History screen. 07/02/97 PAIRG[...]

Configure and View Status 46 Megabit Modem CRA-C User Manual 7 Days ADSL Performance History. The 7 Day ADSL Performance History menu displays the ES and UAS counts, and the minimum SNR margins for the previous 6 days and the current day. The division of the intervals is based on 12 am midnight as the dividing boundary, and the current day count is[...]

Configure and View Status Megabit Modem CRA-C User Manual 47 ADSL Alarm History. The ADSL Alarm History screen consists of five columns. Table 14 describes the information found in each column. Type on the ADSL Menu to open the ADSL Alarm History screen. 09/08/97 PAIRGAIN TECHNOLOGIES 08:47:54 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01 ADSL ALARM HIST[...]

Configure and View Status 48 Megabit Modem CRA-C User Manual Ethernet Bridge Statistics The Megabit Modem CRA-C provides real-time, non-disruptive monitoring of system performance. This menu displays a count of the valid Ethernet and ADSL frames received and forwarded by the 10BASE-T MDI-X and the line ports, respectively. The display is updated ev[...]

Configure and View Status Megabit Modem CRA-C User Manual 49 Table 15. Bridge Statistics Fields Field Definition Ethernet Port Input Frames The number of frames correctly received. Output Frames The number of frames correctly transmitted. Discarded Frames The number of frames dropped due to an overflow of the input or output buffer for the port. Er[...]

Configure and View Status 50 Megabit Modem CRA-C User Manual[...]

Megabit Modem CRA-C User Manual 51 NETWORK AND MANAGEMENT OVERVIEW Through the console menus, you can configure the Megabit Modem CRA-C as a bridge to forward Ethernet data based on MAC addresses or as a router to route Ethernet data based on IP addresses. Additionally, you can configure parameters for management and encapsulation protocols using t[...]

Network and Management Overview 52 Megabit Modem CRA-C User Manual Figure 9. Spanning Tree Topology[...]

Network and Management Overview Megabit Modem CRA-C User Manual 53 You can enable or disable Spanning Tree on the Bridge/Router Configuration Menu. The Megabit Modem CRA-C uses the Spanning Tree defaults shown in Table 16. These values are user-configurable through SNMP as part of the Spanning Tree group in RFC 1493. Table 16. Spanning Tree Default[...]

Network and Management Overview 54 Megabit Modem CRA-C User Manual Figure 10. Simple Configuration for Static IP Routing[...]

Network and Management Overview Megabit Modem CRA-C User Manual 55 Figure 11 shows a more complex example of multiple gateways that use static IP routing to route packets sourced from specific users to different destination gateways. Figure 11. Multiple Gateways Specified for Static IP Routing[...]

Network and Management Overview 56 Megabit Modem CRA-C User Manual When you configure the static IP routing feature, set the parameters defined in Table 17 through the Megabit Modem CRA-C console menus. Set the parameters defined in Table 18 in an external router (used as a gateway). Table 17. Megabit Modem CRA-C Static IP Routing Parameters Parame[...]

Network and Management Overview Megabit Modem CRA-C User Manual 57 Table 18. External Router Static Route Entry Parameter Definition Static Route Entry in External Routers Configure a Static Route entry in any of the external routers which may have been specified as a Default Router or as a Gateway. This is required because the static IP routing fe[...]

Network and Management Overview 58 Megabit Modem CRA-C User Manual Figure 12 shows an example of a point-to-point ADSL system and hypothetical values of parameters defined in Tables 17 and 18. Figure 12. Example for Static IP Routing[...]

Network and Management Overview Megabit Modem CRA-C User Manual 59 Megabit Modem CRA-C IP Addresses The Megabit Modem CRA-C has two IP addresses, one for the ADSL WAN port and one for the Ethernet port. In Figure 13, the non-shaded side of the provider and subscriber modems indicates the LAN address for the Ethernet (10BASE-T) connection. The shade[...]

Network and Management Overview 60 Megabit Modem CRA-C User Manual Figure 13. IP Addresses[...]

Network and Management Overview Megabit Modem CRA-C User Manual 61 Management Protocols SNMP is used for configuring system and bridge parameters, monitoring statistics, and performing advanced management. SNMP This management protocol specifies how to send information between a Network Management System (NMS) and managed devices on a network. Mana[...]

Network and Management Overview 62 Megabit Modem CRA-C User Manual Table 19. SNMP Configuration Default Values Attribute Factory Default Download Image File Name Not configurable via console Local IP Address 0.0.0.0 Local Subnet Mask 255.255.255.0 Boot Router IP Address 0.0.0.0 Default Router IP Address 0.0.0.0 Boot Server IP Address 0.0.0.0 Boot M[...]

Network and Management Overview Megabit Modem CRA-C User Manual 63 The Megabit Modem CRA-C provides an SNMP agent that supports several MIBs for the management of the system. The SNMP agent can process datagrams received from both the Ethernet interface (LAN) and the ADSL interface (Line). The agent and the protocol stack complies with the followin[...]

Network and Management Overview 64 Megabit Modem CRA-C User Manual The Spanning Tree MIB can only be accessed if the Spanning Tree protocol is enabled. PairGain REX MIB an enterprise specific MIB designed for the agent in the Megabit Modem CRA-C for managing the ADSL portion of the unit. The Ethernet interface has the ifIndex value of 1 and the WAN[...]

Network and Management Overview Megabit Modem CRA-C User Manual 65 BOOTP conforms to the following RFCs: RFC 951: Bootstrap Protocol (BOOTP) RFC 1533: DHCP Options and BOOTP Vendor Extensions RFC 1542: Clarification and Extensions for the Bootstrap Protocol (updates 951) A BOOTP request is broadcast through the Ethernet port to the local network. T[...]

Network and Management Overview 66 Megabit Modem CRA-C User Manual TFTP Trivial File Transfer Protocol (TFTP) is used to download networking image code to the Megabit Modem CRA-C from a TFTP server. This allows software upgrades to be performed over the network. The Megabit Modem CRA-C initiates a TFTP download of application code in these situatio[...]

Megabit Modem CRA-C User Manual 67 TECHNICAL SPECIFICATIONS ADSL Line Signal Format CAP Line Code Transmit Signal Power up to 23 dBm Connector RJ-48 Ethernet Port Connector RJ-45, 10BASE-T Bandwidth Filtering 14 Kpps (64-byte packets, both directions) Forwarding Performance 2.7 Kpps Address Learning 2000 MAC addresses with aging Encapsulation Forma[...]

Technical Specifications 68 Megabit Modem CRA-C User Manual Management and Maintenance Embedded SNMP Agent BOOTP/TFTP download (with RFC 1542 extensions) RFC 1533 Dynamic Host Configuration Protocol RFC 1213 MIB II, RFC 1493 bridge MIB (base, ST, transparent groups) PairGain xDSL bridge MIB extensions RFC 1215 Traps (link state) and ST Traps (newRo[...]

Megabit Modem CRA-C User Manual 69 TECHNICAL ASSISTANCE PairGain Technical Assistance is available 24-hours-a-day, 7-days-a-week by contacting PairGain’s Customer Service Engineering group at one of the following numbers: Telephone: (800) 638-0031 (714) 832-9922 Fax: (714) 832-9924 During normal business hours (8:00 AM to 5:00 PM, Pacific Time, M[...]

Technical Assistance 70 Megabit Modem CRA-C User Manual[...]

Megabit Modem CRA-C User Manual 71 LIMITED WARRANTY PairGain Technologies, Incorporated warrants its products to be free of defective and faulty workmanship for a period of 60 months, under normal use, from the date of shipment. PairGain's obligation, under this warranty, is limited to replacing or repairing, at PairGain's option, any suc[...]

Limited Warranty 72 Megabit Modem CRA-C User Manual 2 Provide the following information along with the equipment you're returning: • Your company name, address, and the name of the person whom we can contact in case we have any questions. • The same Purchase Order Number you gave us when you requested your RMA number. • A description of [...]

Megabit Modem CRA-C User Manual 73 GLOSSARY The Glossary defines technical terms and abbreviations used in this manual. Access Provider See Service Provider. Access Rate The transmission speed, in bits per second, of the physical access circuit between the end user and the network. ADSL As ymmetric Digital Subscriber Line. A method of transmitting [...]

Glossary 74 Megabit Modem CRA-C User Manual CAP Carrierless Amplitude Phase Modulation. A two- dimensional line code used in ADSL. Crosstalk Line noise that occurs due to coupling of signals between pairs in the same bundle. Downstream The direction of data reception from the Megabit Modem CRA-C to a remote unit. Ethernet A baseband LAN specificati[...]

Glossary Megabit Modem CRA-C User Manual 75 Mbps Megabits per second. 1,000,000 bits per second. MDI Media Dependent Interface. MDI-X Media Dependent Interface (cross-over). MIB Management Information Base. NVRAM Non-Volatile Random Access Memory. Port An I/O interface. A point at which signals may be introduced or extracted in a similar manner. PO[...]

Glossary 76 Megabit Modem CRA-C User Manual[...]

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Cor por ate O ff ice 14402 Fr anklin Avenue Tustin , CA 92780 Tel: (714) 8 32-9922 Fax: (714) 832- 9924 For Techni cal Assis tance: (800) 638- 0031[...]