Speeds with &N and &U, Command Values, At&N, At&U | 3Com 56K

8-4CHAPTER 8: CONTROLLING DATA RATES

Controlling Link You can use the &N and &U commands to control link speeds.

Speeds with &N and &U

Controlling Link Use the following table to determine how to use &N and &U commands:

Speeds

To limit the	Use

Highest possible connect speed	AT&N

Lowest possible connect speed	AT&U

Range of possible connect speeds	AT&N
	and
	AT&U

The default values for &N and &U are 0. If you change these values, you will limit the speeds at which you can connect. 3Com recommends that you do not alter these values.

Limiting the Highest The &N command, when used in conjunction with the &U command, Possible Connect allows you to limit the highest possible connect speed. If a remote

Speed modem attempts to connect to your Business Modem at a speed higher than &N, your Business Modem will not allow it to connect.

To limit the	Use this command	Where x is

Highest possible connect	AT&N=x	A value from 0 to 32
speed

For a complete list of connect speeds, see the table in section &N and &U

Command Values.

Image 68

3Com 56K manual Speeds with &N and &U, Command Values, At&N, At&U

Contents

3Com OfficeConnect 56K Business Modem Command Reference 3Com Corporation 3800 Golf Rd Rolling Meadows, Illinois United States Government Legend Contents If You Are Using MS-DOS Command and Online ModesOther Operating Systems Making International calls Result Code Display Commands Additional Result Code Subsets OverviewData Terminal Ready Data Set Ready Carrier Detect Overview Serial Port Rates Connection Rates Setting DTE Rate to 230 Kbps Setting up Dial SecurityPassword Prompting Remote Configuration Error Control MNP Error ControlTesting the Business Modem using AT&Tn Received Data Flow Control Digital Loopback Testing AT&T3 Remote Digital Loopback Testing AT&T6, AT&T7Canceling All Digital Loopback Test Requests &T5 Testing Using Keyboard Data AT&T6 Getting New Operating Software Sending New Software to your modemIf Your Modem Doesn’t Respond Hardware Flow Control Software Flow control No Flow Control Registers Additional Specifications Serial PortsSerial Ports Macintosh modem About this Guide IntroductionFinding Specific Information This Guide Conventions Icon DescriptionConvention Description Wait n seconds between losing the connection Related About this Guide Connecting to Your ISP Windows 95/98 Modem software Your modem is now ready to useThis file Does this Is not listed Go to Step If Dial-Up Adapter Do this Is listedNetworking Click Add Protocol Microsoft TCP/IP OK Click FinishIf TCP/IP Dial-Up Adapter Do this Windows 95/98 Step Four Customizing the TCP/IP Settings Click TCP/IP SettingsClick OK, and OK If your ISP Do this Specify an IP address, if needed Click Server assigned IP addressClick Specify name server addresses and enter Click Server assigned server address For you to Use this connection Go to Start Settings Control Panel Modems Setting up RASSelect Remote Access Service and click Properties Check Don’t detect my modem I will select it from a list Click Continue to complete RAS setup Select Start Settings Control PanelGo to Start Programs Accessories Dial Up Networking Click Network Double-clickDial-Up Networking Select Enable software compressionSpecify an IP address by clicking TCP/IP settings Macintosh computers MacintoshMake sure Use Telephony Dialing Properties is unchecked System Configuration Accessing Internet Installation Script and then configure Open Transport PPPInstalling the script Slip or PPP dialing software Transport PPP Go to Apple Menu Control Panels Modem Macintosh Go to Apple Menu Control Panels PPP If You Are Using Other OperatingSystems Windows 18CHAPTER 1 Connecting to Your ISP Using the AT Command SET Using AT commandsOverview General rules for Dial the following number using tone dialing To configure your modem to CommandRe-execute the last-issued command Use the X2 result code subset Settings for a register in the current configuration To display CommandTo change Command ATI5 Understanding Bit-mappedRegisters Getting a list Registers Command and Online Modes If you want to Set the modem to Use this commandModes of Operation ATO0 If you want to Command Return online ModeReturn online and retrain ATO1 Echo Online ModeControlling Local Or Fax mode Data and FaxModes Software manual Class 1 Fax Mode If the modem This indicates Returns a value 6CHAPTER 3 Modes of Operation Dial options DIALING, ANSWERING, Hanging UPDialing ATD@ ATDAtdr Atdl Command does. Also can be used to repeat any Disable carrier loss redialEnable carrier loss redial Redialing This command also defines the interval in seconds Force Answer Mode Go through the answer sequence when it hasntATA Received an incoming call Manually answer a call If you want your modem Command MakingInternational calls International calls above 1200 bps Pulse dialing Call DetectionMake/Break Ratio Caller ID Functions Modem Handles Caller ID Caller ID Action Command An Example of Unformatted caller ID presentationAT#CID=0 AT#CID=1 References Distinctive RingSupport Commands There are four ring patterns in common useAre graphical depictions of each ring pattern.These Ring Result Codes Verbal Numeric NVRAM, and Flash memory Memory type Applies to Loss of power will CommandWorking with Memory Saving a Phone Number to Nvram ATDS2 Saving a Command String to Nvram Displaying S-Register Value InformationAT&F0 AT&F1 Substitute a template other than &F1 AT&F2&W Commands Controlling Result Code DisplaysAdditional Result Code subsets What format they are displayed Additional Result Code Subsets AT&A0AT&A1 AT&A2 Controlling EIA-232 Signaling Tells the modem how to respond to the DTR signalData Terminal Ready Signal Data Set Ready Business Modem sends the CD signal Carrier DetectAT&C0 AT&C1 4CHAPTER 7 Controlling EIA-232 Signaling Controlling Data Rates Serial Port Rates AT&B2 To allow your modem Set the serial port Command Rate asAT&B0 AT&N0 AT&N1AT&N9 AT&N2 Command Values Speeds with &N and &USpeeds AT&N To limit Use this command Where x is Lowest possible connect If &U Then your modem Link Speed Index 46666 48000 49333 50666 52000 53333 54666 56000 57333 KbpsEnhance throughput 8CHAPTER 8 Controlling Data Rates Accessing and Configuring Business Modem Remotely Setting Up Remote AccessIts configuration remotely You should be familiar with these terms before you continue AT%P0=password Accessing the Host Configuration computer You should see a display similar to this AT%B0 AT%B6AT%B1 AT%B7 You can use the AT%Fn command to control the data format Remote-Access Password, return online by pressing CtrlC or typing ATOCommands Quitting aPage Dial Security Setting up Dial Security AT%L AT%L=PW0 To make the host Business Command Example ModemFor your modem to Command Example Enable Local Security Enabled When using Autopass Prompting When using Password Prompting Autopass Dial Security For your modem to enable CommandDial Security with Password Prompting Example Sending AT%E=3 erases passwords for accounts MaintainingSecurity Accounts Account information For your modem to Command Enable Dial Security What the GuestUser Needs to Do Dial Security by entering ATS53.0=1 For your modem to be set Command For your modem to Command Disable Auto AnswerSecurity Remotely Dialing In From the Remote Site 10-10CHAPTER 10 Dial Security Flow Control Hardware and software flow controlReceived-data flow control Transmit-data flow control Control HardwareSoftware Flow AT&R0 AT&R1AT&R2 AT&I1 Enable Hewlett Packard-Terminal mode. Applies only to Does not look for your typed XON/XOFF commandsAT&I4 Characters from the data stream Transmit-Data Flow By its attached computer 11-6CHAPTER 11 Flow Control HANDSHAKING, Error Control Data COMPRESSION, Throughput Handshaking For your modem to Command Enable the call indicate tone Attaining Speeds Above 28.8 KbpsAttaining 56 K Connections Controlling the V.8 Call Indicate Tone Enable DisableCapabilities Other Protocols Leveling ASL Error Control Error-ControlLower-speed Protocols Have no error control Normal Mode Asynchronous ModeAT&M0 AT&M4 Scheme similar to MNP Flow ControlTwo reasons Remote end until it is acknowledged by the receiving device For the modem to Command AT&K0AT&K2 AT&K3 Getting Maximum ThroughputMaximum Throughput results Public Domain Effects Getting Maximum Throughput Page Here is a complete list of ATI n commands Displaying Querying and Help ScreensQuerying Product code, and call duration ATI2 ATI3ATI7 ATI11 For your modem to display Command AT$ 13-4CHAPTER 13 Displaying Querying and Help Screens Testing the Connection Testing the Business Modem using AT&TnTesting the Business Modem using S-Register All loopback testing conforms to ITU-T Recommendation AT&Tn Testing the BusinessModem using Using AT&T1 Using AT&T8 Loopback DL testing AT&T6, AT&T7 Phone line. Data flow is shown in the figure belowThere are two remote digital loopback options Request AT&T4 Testing Using Keyboard Data AT&T6 14-8CHAPTER 14 Testing the Connection Testing the Business Modem using S-Resister For your modem to use Use one of these commandRemote digital loopback using keyboard data Remote digital loopback with built-in test pattern Testing Using Keyboard Data ATS16=8 Starting Testing That Uses the Test Pattern To use the test pattern during Command Testing withWhen S16 is set to 4, the Business Register 14-12CHAPTER 14 Testing the Connection Troubleshooting Problems That Occur Before Connecting Display verbal messages For your modem to Command Enable message displayBusiness Modem wont dial Double characters are appearing on your monitor Hear ringing but the Business Modem wont answer Problems that Occur After Connecting Your screen displays random or garbage characters Mainframe computer keeps dropping your connection Errors during software download If You Still Have Problems Problems that Occur After Connecting 15-8CHAPTER 15 Troubleshooting Upgrading Your Modem Checking Your Business Modem’s Software Version Getting New Operating SoftwareSending New Software to your Enter AT~X!. The modem should respond as follows If Your Modem Doesn’t Respond Registers How bits areMapped to decimal Values Converting Bits to Decimal Values01001111 113 Using Bits Using DecimalSettings Values of the bits and entering the total Bit-mapped registers have up to eight functions Register Default Function Complete list of S-Registers Bit Value Result Be a problem if you expect a great Number of errors during a callOff their screens. When remote Information about setting bit-mapped registers. For Up. S19=0 disables the timer To ARQ mode onlyDefault is 3 seconds Enable ITU-T V.21 modulation at Bit Result Disable the remote-access busy 128 Disable V.32 terbo S38Thus enabling or disabling remote access Default setting of zero allows no remote login Dial security enabled Prompting enabledEnabled Disable 2400 symbol rate Disable precoding Disable shapingDisable V.34+ 128 Disable V.FC S58 Command Function Alphabetic Command SummaryBasic Command Set Optional parameters When other modems share the line Store the number in memory using the &Z commandDisplay help for the dial commands Command mode echo ON. Your typing will Display the actual time. Set the clock using Control when the speaker soundsBetween command and online modes Errors in a non-ARQ data transfer Ampersand Command Set CD when it disconnects Mode during a call by dropping DTRWith the Hn command DTR signal. Dropping DTR ends a call Software support XON/XOFF signaling Recommended setting for ARQ modeMode only Error control. For this to work, the remote device This setting to transfer compressed files Selective data compression. The modemNegotiates only for V.42bis compression, Line type Normal Ampersand & Command Set B-9 Enable hardware flow control of received data Send the computer a Data Set Ready DSR signal viaOriginate mode Send DSR after dialing, on When Carrier is lost, send a pulsed DSR signal Percent % Command Set Create and configure security accounts Remotely configure a modems serial port rateB10 115200 bps Remote configuration control Cancel configuration changes and restore Octothorpe # Command Set 14APPENDIX B Alphabetic Command Summary Template send AT&F1 to your modem Flow Control TemplateHardware Flow 19.2 NoneDTE rate* Kbps Template send AT&F2 to the modem Software flow control Basic Even 9600 6APPENDIX C Flow Control Template Result Code Meaning Result Code Meanings SetsResult Code Meanings Result Codes Sets for Xn Values 10/CONNECTFunctions Wait for 2nd Dial Tone W Wait for Answer @ Specifications Technical InformationTechnical Schemes are supported Error Control, Data DialingAdheres to the following standards This Supports Word Length Parity 1 Bit Stop Bits This feature SupportsAdditional DB-25 DB-9 Pin Function Transmitted Data Received Data Signal GroundOperate asynchronously follows Most reliable performance Mac Pin Mac Pin Description Modem Pin Modem Pin Description Macintosh modem Ascii Chart 2APPENDIX F Ascii Chart Fax Service Class 1 Commands FAX Service ClassFollowing optional Class 2.0 fax commands FAX Information for Programmers FCC Notice Fax Mode FlowControl Setting Is making a data connection using an error control Viewing LedsThis LED Status Means your Business Modem Protocol RS232 mode has detected DTR signal USB mode has detected successful USB registrationOff RS232 mode has not detected DTR Off Has not detected the RTS signal from your computer Registers Their Functions and Default Settings Counts and stores the number of rings from an incomingCharacter. Valid range is 0*127 Valid range is 0*127 Disable 250 ms pause before result On DTR signal, autodial the numberAt power-on/reset, autodial number Disable HST Problem if you expect a great For HST modulation onlyFrom 1.5K bytes to 128.* for Calls from remote users of slower Line, and at the timeout the Business Modem hangs up S19=0 disables the timerDisable V.32 modulation used for Remote digital loopback Register Default Function Bit Value Result Disable the faster retrains that occur 128 Disable V.32terbo S38To acknowledge receipt of all transmitted data. Default = Thus enabling or disabling remote access. The default Reserved Disable V.8 Call Indicate CI128 Enable phase roll detection Disable preemphasis Enable ring type aEnable ring type B Enable ring type C Warranty Corporation Limited Warranty 3Com Client SRO# 3COM Corporation Limited Warranty J-3 Statement FCC RegistrationFCC Certification FCC Notice Radio Television Interference Canada Glossary Glossary Glossary Glossary Glossary Glossary Glossary Glossary Glossary Glossary Transmission rate See it rate Receiver/Transmitter Glossary Glossary Glossary