FaxChange Throughput - Faxchange 6.x

FaxChange Throughput

How many faxes will one fax line send per hour ? How many fax lines must I have to be able to send 1000 faxes daily ? These are very commonly asked questions by FaxChange users. This document will attempt to answer them.

"Ideal" channel capacity

Initially it was necessary to designate a maximum fax quantity which depart under ideal conditions via one line per hour. We quantified this attribute experimentally.

Test configuration

FaxChange 5.0, faxmodem ZYXEL U1496E (class 2) with a pause of 1 second after transmission. Configuration of the computer was seen as irrelevant here so was purposely left out.

Transmission of faxes occurred at a speed of 9600 bps which is the most commonly used connection speed. Reception of faxes was FaxChange with a Brooktrout Tr-114 fax card connected via the branch exchange. Transmission of course succeeded with the first attempt.

Results

In accordance with used fax lengths the results are as follows:

Cover page (approx. 1/4 of A4 size) + approx. 3-4 pages of A4 text (short price list, last minute offer...)	36 faxes per hour
Cover page (approx. 1/4 of A4 size) + approx. 3 pages of A4 text	14 faxes per hour

Transmission success

From the start we ascertained the number of faxes per hour via one line that could be transmitted. In practice, however, not every fax will be transmitted successfully and this is a generally very important number which is directly affected by the capacity of the line in operation.

To prevent having to work with mere estimations the Datasys database was examined and the following figures were produced:

During the archiving process some 4176 transmitted faxes were processed (whether its transmission was successful or not). The total number of attempts was 11252 which equates to approximately 2.7 attempts per fax.

It is of course necessary to realise that if the fax number dialled was non-existent the standard installation of FaxChange is configured for 7 attempts therefore unnecessarily wasting time by re-attempting. In this example the Datasys installation was set up for 10 attempts. Therefore, Datasys only considered faxes confirmed as being sent. A total of 2704 faxes along with 3593 attempts equates to 1.3 attempts per fax.

From this example it is clear that the above process depends heavily on the state of the operational addressee database. If the database is well maintained (therefore forcing all errors to be caused solely by temporary engagements of destination fax numbers or simply erroneous fax numbers) the result of 1.3 attempts per fax maybe taken as a realistic attainable target. With the database in only an "average" state the attempts count will quickly reach the shown figure of 2.7 per fax.

Overall channel capacity of FaxChange

In view of the previous paragraph we can say: attainable capacity of 1 fax line varies from approximately 27 faxes per hour (short content with well maintained addressee database) to approximately 5 faxes per hour (longer content, more errorneous fax numbers).

Finally if you wish to send 1000 short faxes daily while operating a good quality addressee database it will be vital to reserve 1000 / (24 * 27) = 2 fax lines. When considering longer faxes and a more "average" addressee database the figure will quickly mature into 1000 / (24 * 5) = 9 fax lines.