Types of ISDN Accesses

For the connection from ixi-UMS Business near your PBX / NTBA you need a BRI – BASIC rate interface (also famously as a S0) connection. This permits a maximum number of 2 concurrent connections.

The connection can be configured two different kinds:


·Point-To-Multipoint (PMP)

This mode can only be applied with S0 accesses. PMP means that you have a number of so called MSNs (Multiple Subscriber Number) available on the access for addressing end users. The number of MSNs depends on whether you have a Telecom ISDN (up to 10) access or a PBX ISDN access (limit depends on PBX). Each MSN represents the address of one end user on this access.


·Point-To-Point (PP)

Instead of MSNs, so-called DDI digits (Direct Dial In) are used to address end users. This means you have a main number for the access and a number of dial in digits which may follow after the main number (usually at least 2). For example with two direct dial in digits, 100 (00-99) end users can be addressed.

In many PBX's, Q-SIG offers most features in combination with ixi-UMS Business and the ixi-UMS Business Enhanced Voice Package.


Call number transfer to the ixi-UMS Business Server

For the operation of a server-based Unified Messaging Systems, the transfer of the recipient number and the sender number are relevant. With inbound calls, the call numbers are canonized by the ixi-UMS Business Server into a number in the international E.123 format according to ITU-T E.164 (international numbering plan).


In special cases, it may make sense to transfer the recipient number in international E.164 format. If so, this funktion must be aktivated in the ixi-UMS Business Server.


·Recipient number

The ixi-UMS Business recipient number should be transferred to the ixi-UMS Business Server as extension/MSN. The ixi-UMS Business Server completes this to an E.123-standard number.


·Sender number

With the sender numbers sent to ixi-UMS Business by the PBX, "NumberingPlan" (NP) and "TypeOfNumber" (ToN) information must be consistent with the format of the number itself.



A ixi-UMS message is received at the site in Munich from the sender number +49 89 123456. The transfer from the PBX / NTBA to ixi-UMS Business e.g. can be transferred via one of the following "information pairs" (NP/ToN):


NP ( NumberingPlan)

ToN (TypeOfNumber)

Transferred Number




ISDN - E.164



ISDN - E.164



ISDN - E.164



ISDN - E.164



ISDN - E.164





When a number NP or (and) ToN "Unknown" is signaled by the PBX or the outside line, the internal number conversion rules of the ixi-UMS Business are activated. If "Remove outside line access" is selected, for example, the ixi-UMS Business Kernel can remove this. In every other case, these rules do not apply.


·Redirecting and Redirection Number

When the ixi-UMS Business with the inbound routing option global "voice-mailbox number" (Route-by-Redirection) shall be used, this must be transferred to ixi-UMS Business as:


with DSS1

Redirection Number, ETSI ETS 300 207


with QSIG

divertingLegInformation, ECMA-174


·Call transfehr and callback with ixi-UMS Business

When the features transfer and/or callback shall be used, the following features must be supported in addition:


§ECT (ExplicitCallTransfer)




·Additional information:

The service HOLD is needed to hold an active call in order to make the call transfer after having made a consultation call.

Retrieve is needed when the consultation call or the call transfer was not successful in order to reactivate the held call.


Punkt-to-Multipoint (PMP)

Point-to-Point (PP), DSS1

Point-to-Point  (PP), Q-SIG

HOLD/Retrieve (Call Hold, ETS 300 139)

ECT (Explicit Call Transfer, ETS 300 367)

KEIN ECT möglich


Path Replace ECMA  175/176

Call Transfer ECMA 177/178



If the PBX does not support the ECT or a PP must be deployed, the ixi-UMS Business Server can "emulate" this feature. Please turn to ixi-UMS Business support department.

This features is only possible with the ISDN-board Dialogic DIVA Server BRI.



·In a lot of PBX's, Q-SIG offers the most features in combination with ixi-UMS Business. Because of this, we recommend to use the protocol Q-SIG with the deployment at a PP-connection.


Version 7