Special Report:

Lucent LT Win Modem FAQ

Contents

Where can I get new firmware/drivers/V.90 upgrades for my modem?

Is there software for Windows NT 4.0?

Is there software for Linux, OS/2, or other non-Windows operating systems?

How do I know if I have a Lucent LT Win Modem?

Is a Lucent LT Win Modem the same as a 3Com/U.S. Robotics Winmodem?

I'm not getting high speeds with my LT Win Modem. Why is that?

I'm getting disconnected a lot. What should I do?

Do the LT Win Modems support caller ID?

Where can I get a manual with AT commands?

What init strings control whether K56flex and/or V.90 are used?

How do I know if my modem supports V.90?

How can I get information about the last call and interpret the results?

How do I limit the maximum connect speed?

Where can I get new firmware/drivers/V.90 upgrades for my modem?

This is one excellent feature of the LT Win Modems. No matter who sold you your modem - Compaq, CPI, Hewlett-Packard, IBM, Sony, etc. - the firmware is all the same. You can use any other company's firmware with one catch.

The only catch is that with older firmware there were separate versions for the LT Win Modem and LT PCI Win Modem. Beginning with firmware version 5.04, the LT Win Modem and LT PCI Win Modem use the same firmware, so everything is completely interchangeable (as per conversation with Lucent).

Incidentally, this does not work with most other modems. For instance, Rockwell chipset modems start out the same, but individual vendors (Hayes, Motorola, etc.) customize the chips and firmware before selling the modems. That's why there are no generic firmware upgrades for Rockwell chipset modems. Likewise for Cirrus Logic or U.S. Robotics chipset modems.

The other advantage of LT Win Modems is that installing new firmware can't possibly damage the modem. In contrast, with most modems there is a slight chance that upgrading the firmware will damage the programmable ROM chips.

Here are a few sources of LT Win Modem firmware and drivers. If you are experiencing problems or slow connects, it's always a good idea to get the most recent firmware.

Links

You can find the very latest Lucent firmware on Richard Gamberg's Lucent page.

56K.COM V.90 Upgrades - you can try finding upgrades from your manufacturer first. Your manufacturer may not have the latest version, though.

Is there software for Windows NT 4.0?

Yes. Check the resources listed above and use any of the files marked for Windows NT. Digitan is one company with NT files, though they may or may not be the latest.  

Is there software for Linux, OS/2, or other non-Windows operating systems?

No. This is one of the disadvantages of software-based modems: to function, they require drivers specific to the operating system.

How do I know if I have a Lucent LT Win Modem?

Issue an ATI3 in a terminal program, or check the ATI3 response in the Windows 95 Modem control panel. Most LT Win Modems will identify themselves when they receive the ATI3 command.

Some Toshiba and Compaq embedded modems are LT Win Modems, even though they don't identify themselves as such.

Is a Lucent LT Win Modem the same as a 3Com/U.S. Robotics Winmodem?

No. Both are software-based, but the AT commands and other information in the FAQ only apply to LT Win Modems.

I'm not getting high speeds with my LT Win Modem. Why is that?

As with any 56K modem, many things can prevent high speed connections. Check the extensive advice in the 56K Troubleshooting Guide for curing slow connects.

I'm getting disconnected a lot. What should I do?

Lucent advised several possible solutions. Part of the rash of current problems may be with the current code (1.2.5) in 3Com/U.S. Robotics HiPer DSP modems, used by a number of ISPs. Recent Lucent firmware (including 5.25) include workarounds for that specific problem.

Of course there can be lots of reasons for disconnects with any type of modem. Try the advice in the Disconnect section of the 56K.COM Troubleshooting Guide.

One strategy for eliminating disconnects is to try limiting the maximum connect speed. See "How do I limit the maximum speed?" below.

Do the LT Win Modems support caller ID?

Some do, some don't, depending on how the distributor configured them. Lucent writes:

If your modem's hardware supports Caller ID, use the V.253 standard command AT+VCID=n command, where

n=0 disables Caller ID
n=1 enables formatted display
n=2 enables unformatted display

Where can I get a manual with AT commands?

Encore has one at http://www.encore-usa.com/Hostat.pdf. Lucent has confirmed that the commands will work for both ISA- and PCI-based LT Win Modems.

What init strings control whether K56flex and/or V.90 are used?

These strings are for ISA card Lucent LT Win Modems and PCI card LT PCI Win Modems.

For enable and disable strings for Lucent Venus chipset modems, as well as non-Lucent modems, see the V.90 Upgrade FAQ.  

How do I know if my modem supports V.90?

These strings are for Lucent LT Win Modems and LT PCI Win Modems. For other modems, see the V.90 Upgrade FAQ.

Issue an ATI3 in a terminal program, or check the ATI3 response in the Windows 95 Modem control panel.

If the ATI3 response shows firmware version 5 or higher, the modem supports V.90. If you're having problems getting a V.90 connection, try upgrading your firmware, try explicitly telling the modem to use V.90 or K56flex (using one of the init strings above), or try the other advice in the troubleshooting guide.

How can I get information about the last call and interpret the results?

In a terminal program, type ATI11.

These are example results using recent firmware. If your results are formatted differently, try upgrading your firmware.

The line numbers have been added for clarity. Each line is explained below.

ati11

Each of the line items in the ATI11 result is explained next:

1. V90, 56K (K56flex), V.34, or V.32 depending on the type of connection negotiated.

2. Initial upstream rate

3. Initial downstream rate

4. Current or final upstream rate

5. Current or final downstream rate

6. LAPM or MNP or None, depending on V.42 negotiation

7. V42bis or MNP or None, depending on V.42 negotiation

8. Mean-square error of received downstream signal. Difference between received constellation point and reference decision point. This is a dimensionless decimal number, only valid during a call. Higher numbers are worse. There's no absolute threshold of goodness; it depends on the downstream data rate. The number varies during a call, so it can be useful to sample it a few times.

9. The received signal power, although labeled -dBm, is only a relative measure for comparing calls to/from different locations. Only valid during a call.

10. Upstream transmit signal power.

11. Round-trip delay reads differently for different server types, so can be used as a relative measure to compare connections to the same type of server.

12. Echo levels are valid for V.34 only.

13. Echo levels are valid for V.34 only.

14. Number of LAPM frames sent upstream during this call.

15. Number of REJ frames received at the analog client modem.

16. Number of LAPM frames received by client during this call.

17. Number of frames received in error by the client.

18. Number of retrains or rate renegotiations requested by this modem.

19. Number of retrains or rate renegotiations requested by remote modem.

20. Reason for call ending, only valid after call ends:

0 = Local modem command: ATH, DTR drop

1 = Remote modem: cleardown, loss of signal

2 = No answer, busy, etc.

3 = Training failure, K56flex or V.34.

4 = Protocol failure if required by \N4, for example.

21. For PCM modes only, a hexadecimal 6-bit pattern of T1 frames with robbed-bit signaling.

22. For PCM modes only, the downstream digital loss.

23. For K56flex only, the V.8bis info sent by the server. Meaning is defined at the server and by convention. Example above is from Ascend MAX in mu-Law.

How do I limit the maximum connect speed?

It is sometimes useful to be able to limit the maximum connect speed, particularly if you are getting disconnected frequently.

Add these commands to the end of your init string.

To force a particular K56flex downstream rate, use S-register S38. S38=0 disables K56flex, and may allow a more reliable V.34 connection. S38=1 default allows the modem to select the downstream rate automatically. Other values of S38 force the downstream rate, with fallback to V.34 if unsuccessful at the configured rate:

The number of robbed-bit signaling (RBS) frames detected decreases the true DCE rate per the following table:

For example, if S38=10 and there are 3 RBS links, the K56flex downstream rate will be 48-4=44 kbit/s. The exception to this is for 32 kbit/s and 34 kbit/s, which are the true rates regardless of the number of RBS frames detected.

For V.90

-- Les Jones