Via Systems Technical Support

Via Systems

Technical Bulletin

Summary: Using calling cards to dial up remote sites.

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Symptom:

User needs to use ViaDuct to connect to a remote site which is a long distance call. To make the call the user needs to use a calling card.

Problem:

Via Duct users may have the need to use a calling card to dial in to remote systems. A typical dial command string should, assuming a touch tone telephone, resemble:

ATDT xxxxxxxx,,,,y yyy yyy yyyy,,,,zzz zzz zzzz zzzz

The first group of x's is the number dialed to access the user's long distance carrier, if necessary. The grouping of y's is the actual number being dialed, while the grouping of z's represents the user's calling card number. The commas represent one second pauses; the number of commas used should be adjusted as necessary.

There is a limitation on the number of characters that can be placed in a modem command string. This is a limitation set by the modem manufacturer. For many modems, the length of the command string must not exceed 40 characters (check your modem manual for the command string buffer size). Commas do count as characters, while spaces are not counted as characters in the string. If your dial command string exceeds the command string buffer, you may get an "ERROR" message returned by the modem.

Solution:

Most modems (again, check your modem manual) allow you to continue the command string on the next line by placing a semicolon (;) at the end of the first dial command string. After dialing the first part of the string, the modem will return an "OK:" message, but you will be left in command mode, thus holding the line for further commands. In the above example, the dial command strings may be broken down as follows:

ATDT xxxxxxxx,,,,y yyy yyy yyyy,,,, ;
OK
ATDT zzz zzz zzzz zzzz

Dial strings may also be set up in the Via Duct Dial menu for frequently called numbers. If you are faced with a dial string that exceeds your modem's command buffer, it may make sense to set up the calling card number portion of the dial string as a separate entry in the Dial menu. If you do this, be sure that you include the semicolon (;) at the end of the first dial string.