Multi Tech Equipment MTA128ST You cannot place two simultaneous data calls, Data is being lost

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Troubleshooting

You cannot place two simultaneous data calls

You may not have ordered an ISDN line configuration that supports two simultaneous calls. Check your contract or latest statement of service from your ISDN provider. Also, your ISDN provider may have programmed the switch incorrectly. Call the provider.

You may have misconfigured your MTA128ST/NT to dial two simultaneous data calls. The command AT&J1&W0<cr> is used to indicate whether outgoing calls should be made on two B-channels by default.

You may be using the wrong bundling dial modifier (e.g., ATD7853500&7853502<cr>). The ampersand in this command string is correct. Other valid characters joining two telephone numbers include a plus sign (+) and an exclamation mark (!).

Note: In Windows 98/NT/ME, if the Use Country Code and Area Code box is checked in the Properties window for dial-up connection, the bundling modifier (i.e., &, + or!) is removed from the dialing string when the user attempts to make a connection. The solution is not to check the Use Country Code and Area Code box or to simply add the bundling dial modifier to the phone number at the time of connection.

The MTA128ST/NT disconnects while online

Check for loose connections between the MTA128ST/NT and the computer, the ISDN jack, and AC power.

The problem may have originated at the other end of the line. Try again.

If you were online with a BBS or online service, it may have hung up on you because of lack of activity on your part or because you exceeded your time limit for the day. Try again.

The MTA128ST/NT cannot connect when answering

Autoanswer may be disabled. Turn on autoanswer in your data communications program or send the command ATS0=1 to your MTA128ST/NT in terminal mode.

Note: If the user wishes to accept calls while DTR is low, the MTA1 28ST/NT must be configured to ignore DTR. This is accomplished by entering AT&D0<cr>. With this configuration, the MTA128ST/NT is able to accept calls while DTR is low. If this configuration setting is not made, the TA rejects incoming calls until DTR is high while the calls comes in.

File transfer appears slower than it should be

If you have a Universal Asynchronous Receiver/Transmitter (UART) that is compromising data throughputs, we recommend replacing it with a special I/O card.

If you are running under Windows 3.1 and have a 1 6550AFN UART, replace the Windows serial driver, COMM.DRV, to take full advantage of the UART’s speed.

Check the serial port baud rate in your communications software, and make sure it is set as high as your UART allows.

Data is being lost

Your UART may not be reliable at serial port speeds over 9600 bps or 19,200 bps. Reset your serial port speed to a lower rate, or replace your serial port with a faster one.

Check the serial port baud rate in your communications software, and make sure it is set as high as your UART allows.

Make sure the flow control method you selected in software matches the method selected in the MTA1 28ST/NT.

Garbage characters appear on the monitor

Your computer and the remote computer may be set to different parities. Check with the remote system and set your communications software to use the same parity as the remote system.

Making a V.120 call, caller gets a NO CARRIER message after dialing the number.

Some switches don’t support ISDN SETUP messages that contain a LLC (low layer compatibility) element. When these switches receive an LLC in the SETUP, they immediately reject the call and a NO CARRIER message displays. Disable LLC for V.120 calls by issuing the command AT!D0=0. To enable LLC again for V.120 calls, issue the command AT!D0=1 (the default setting).

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Contents Page Model MTA128ST/NT S000305C Rev. C Revision Date DescriptionTrademarks Contents Introduction and Description Product DescriptionFeatures Spid Service Profile IDIsdn BRI Line NT1 ConnectionPin TE Signal InterlacePin LED Indicators LED P1 LED P2 LED Switch Compatibiltiy LED IndicatorsCommand Interface ConnectorsHardware Installation Safety WarningsConnecting your TA Connect the TA to Your PC RS-232 Connection Configuration Utilities Network ConfigurationIntroduction Before You StartCall Control Configuration Voice TEICOM Port Settings Dialing NumbersDCD Drop Time Configuring your TA Page Page Page Page Page Page Page Page MTA128S T/NT Commands and S-Registers AT CommandsAT Commands by Function Digital Data Call Commands a Analog Pots Call CommandsRegisters Register SummaryAT Commands, S-Registers, and Result Codes Using AT Commands to Operate the MTA128ST/NT Result CodesMaking a Call Answering a CallHanging Up Answering ManuallyAnswering Automatically Troubleshooting the TA Specific Troubleshooting SituationsTroubleshoot ing IntroductionDebugging/Logging/Troubleshooting Commands Debugging/Logging/Troubleshooting S-RegistersNone of the LEDs light when the MTA128ST/NTis on Debugging/Logging/Troubleshooting Command Summary ATMTA128ST/NT does not respond to commands MTA128ST/NT dials but cannot make a connection You can place data calls but not voice calls or vice versaMTA128ST/NT cannot connect when answering You cannot place two simultaneous data callsMTA128ST/NT disconnects while online File transfer appears slower than it should beApple Macintosh Compatibility Bonding Using the &, I and + Characters Making PPP/MLPPP ConnectionsSoftware Applications that can Format PPP Data Dynamic Bandwidth Allocation DBADBA Features Bandwidth-on-Demand BOD-S60, S61, S62, and S63 DBA Data ProtocolsPPP/MLPPP Warranty, Service, and Tech Support WarrantyRepair Procedures for U.S. and Canadian Customers Replacement Parts Repair Procedures for International DistributorsAppendixAConfiguration Profiles Quick Setup Factory ProfilesQuick Setup Example Bearer Service Appendix B Ordering Your Isdn Li neLoop Qualification Using Isdn Ordering Codes IOCs J3 previously Generic Data J-1DN Capability S previously Generic Data MM5 previously Generic Data M-1DN Ordering Isdn Without IOCs Appendices Appendices AppendixC FCCand Canadian Regulation FCCCanadian Limitations Notice AppendixD Configuration Methods Firmware-based Configuration UtilityConfiguration via AT Commands Using AT Commands to Configure the MTA128ST/NTSymbol GlossaryGlossary IETFInternet Engineering Task Force PPPMultilink Protocol or MP-is an Internet Glossary TA-Seeterminal adapter Information pages from a central resource. See also Isdn Index Canadian Regulation 56 AppendixUart