Confusing if the isdn 30 will not allow international numbers to be shown, i think your supplier is talking rubbish , As on IDSN you can only present an number if it exists on the pipe unless you cant negotiate..... see below for BT , you would be looking at type 4 or 5 number presentation. This really depends on a lot , you could have one sip trunk with a German CLI (usually you need to provide proof of address in country) and use that on the IPO ,
Types of Presentation Number
Type 1
A.4. A presentation number generated by the subscriber's network provider. The number is stored in the network and applied to an outgoing call at the local exchange by the provider. Because the number is applied by network equipment there is no need for it to be verified each time a call is made – instead the level of authenticity will depend on the checks made by a network provider that a subscriber is entitled to use a particular presentation number.
Type 2
A.5. A presentation number which identifies a caller's extension number behind a DDI switchboard. Although the number or partial number is generated by the user's own equipment, the network provider is able to check that it falls within the range and length allocated to a particular subscriber. In this way the authenticity of the number may be ensured. It should be noted that some network providers classify type 2 presentation numbers as network numbers (especially where the full number is constituted at the local exchange). This type of number is considered to carry sufficient authenticity to be classified as a network number and is carried as such by some networks.
Type 3
A.6. A presentation number limited to the far-end break out scenario where a call's ingress to the public network may be geographically remote from where it was originated. The number is generated by the user's equipment and is not capable of being subjected to network verification procedures. Verification is based on a contract between the subscriber and the network operator in which the subscriber gives an undertaking that only authentic calling party numbers will be generated.
Type 4
A.7. A presentation number available for the onward transmission of the originating number where a call breaks into a private network and breaks out again before termination, as in a DISA scenario. On the break out leg the number is generated by the user's equipment although it will have already been verified in consequence of having been delivered to the private network. To maintain the verification it is necessary to ensure that the number submitted by the private network is the number that was received.
A.8. Network providers wishing to offer a type 4 service will require a contractual commitment from customers that they will only submit CLIs that have been received from the public network. Unlike other types of presentation numbers, type 4 numbers may not always be diallable; this will depend on the nature of the number received from the public network.
Type 5
A.9. Presentation numbers that identify separate groups of callers behind a private network switch wishing to send different outgoing CLIs. A typical scenario is a call centre making calls on behalf of more than one client. Type 5 presentation numbers are generated by the user's equipment. Subscribers will need to enter into a similar contractual commitment with their network providers as for type 1 presentation numbers - that they are entitled to use the numbers they have selected.
I suppose you could get trial sip license( you need a vcm resource in the system and a decent dedicated data circuit, but for testing purposes you could use current adsl etc)).... on ipo set up the routing so say they prefix with a 7 or whatever...... the call goes over the sip trunk back into the system the system twins with a dummy station that dials out over PRI and is pre programmed to dial this german conter part, and then passes on the number down the isdn30 with type 4 or 5 presentation (number pass through.
But this is very very silly why not just invest in some sip trunks from a decent supplier and get geographical presentation based on who they dial , the initial cost might make them think its a bit pricey , but a total switch from ISDN30 to SIP (with correct bandwidth security and programming ) is the obvious way to go here.And will pay for itself quicker than you think ...... ( but sip is all about having the correct bandwith , dedicated with adequate security)
APSS (SME)
ACSS (SME)
ACIS (UC)
