Voice over IP

A connection of ixi-UMS Business via IP can be realized via H.323 or SIP. The ixi-UMS Business Server hereby can initiate calls via a gateway or a gatekeeper / proxy. Requirements for the connection via VoIP in order to guarantee the functionality of the single services of ixi-UMS Business:




Variant 1: T.38

RTP/RTCP with the Codecs G.711 ALaw or µLaw

Variant 2: "SoftFax" / "Fax pass trough" with

SMS via fixed lines:

RTP/RTCP with Codec G711 ALaw or µLaw, Clearchannel (no echo cancellation, no VAD, no ComfortNoise, etc.)

RTP/RTCP with Codec G711 ALaw or µLaw, Clearchannel (no echo cancellation, no VAD, no ComfortNoise, etc.)


·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 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 use of H.323, the sender number information of the "NumberingPlan" (NP) and "TypeOfNumber" (ToN) sent to ixi-UMS Business from the PBX 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 Kernel 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.


In the SIP-protocol, the fields "NP/ToN" do not exist. The call number format always is "unknown".

With the use of SIP, the ixi-UMS Business Kernel must be set up in dependence of the transferred call numbers. Recommended is the transfer of the recipient number as "extension" (DDI/MSN) and the sender number as national (089 598741) or international (0039 1 6554788), this means always with prefix.


·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 SIP: SIP Diversion Header

§with H.323: H.450.3


·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:


bei SIP:

bei H.323:

Standard SIP "INVITE" und "REFERE"

H.450.2 "Call Transfer supplementary service for H.323."

H.450.4 "Call Hold supplementary service"


·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.


Version 6