Connection to PBX and phone numbers

An important point by the integration from ixi-UMS Business is the binding to the public telephone network.

This binding over a PBX should be carried out by a TK engineer. On this occasion, it is about configuration of the PBX and connection near the PBX.

For the connection from ixi-UMS Business is necessary bintec elmec device for ISDN binding or a XCAPI for VoIP connections.


In order to find out how many B-channels you need, you must take into account the number of incoming and outgoing messages per day. You can use the following figures:


- A fax page takes 1 minute to be transmitted. Failures and retries included.

- One SMS-message takes only a few seconds to be transmitted and can be neglected in this calculation.

- Voice-massages should be treated like fax messages in this computation.


Another important thing that has to be kept in mind are the peak hours, e.g. in the morning when people start to listen to their new voice-messages or in the evening when marketing people might start fax campaigns.




Example a)

·A company has only two employees,

·the task of these employees is to send a large amount of mail merge faxes every day  (e.g. mailings).

·A mailing consists of 500 fax-messages à 2 pages (=1.000 pages)  

·ixi-UMS Business Server configured with four B-channels.


A fax page needs 1 minute to be transmitted, in this case the transmission of the mailing would take 250 minutes using the 4 B-channels



Please bear in mind: In these 2 to 4 hours, no other messages can be sent or received, except one channel has been reserved for the reception, which prolongs the delivery time.


Example b)

·Company with 100 employees

·The services Fax and Voice are used

·About 1000 fax pages are send and received per day

·The faxes are sent and received mainly between 8 a.m. and 6 p.m.

·Every telephone shall get a call forwarding (when busy) to the ixi-UMS Business Server


Calculation Fax:

1.000 pages x 1 minute / page = 1.000 minutes = 16.6 hours


The delivery time for 1.000 fax pages with 1 B-channel would be about 16.6 hours. In order to be able to receive the faxes in the period between 8 a.m. and 6 p.m., at least 2 channels would be required.

During this period, no channel would be available for the feature Voice (voice box). Moreover, you have to take into account that the distribution of the send and received fax messages is not consistent.


Calculation Voice:

At the company, roughly every 15 minutes, a call is forwarded to the ixi-UMS BusinessServer. They want to make sure that there is always a free line available for the voice box.  


In order to guarantee the availability of the voice box and the sending and reception of faxes for every user, at least 8 channels should be deployed.

For further information and calculation examples, please contact:


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