PC Ext: External May Fail to Answer Incoming Calls (128585)

SUMMARY

An asynchronous instance of External may occasionally fail to answer an incoming call. When this happens, the phone rings several times, the modem does not go off-hook, and the line is not picked up. The caller will see a No Answer response to the dial attempt. If the caller attempts a second call, the call will often go through without any problem.

For the best results, set up separate instances for your asynchronous connections and for these instances, include the MailerDisable and DispatchDisable options in the EXTERNAL.INI file.

NOTE: There must be another instance of External that can perform the Mailer and Dispatch functions before the options mentioned above can be used. Other steps can be taken to minimize the chance of unanswered calls. See the section below for additional information.

MORE INFORMATION

External is coded to poll for incoming calls. Thus, External will periodically check the communications channel for activity. Ordinarily, External will reach one of these polling points during the rings of an incoming call, and it will pick up the call.

When factors exist that effect the performance of External, that is, slow its cycle, there will be an increased chance of not reaching the polling point while the call is occurring.

Here are some factors that can slow External and cause missed incoming calls:

Slow Network Links
Congested Network Links
Slow Server Response
Slow PC used for External
Defective Hardware

These factors should be investigated and conditions improved, if possible.

If a wide area network is involved, it might be possible to use the DrivesWAN option of External. This is similar to using the DispatchDisable and MailerDisable options, but does not require a second External at the local site. DrivesWAN does require that there be other External programs running at other sites.

Also, External will not answer incoming calls while it is updating information from one of the postoffices. Checks for updates occur at regular intervals determined by the IntervalUpdate parameter. An update does not occur at every check, but if changes have been made through the Administrator's program (ADMIN.EXE) or Import program (IMPORT.EXE), then the update takes place. The update interval can be increased so that checks occur less frequently and at more controlled times of the day.