DDI

Direct Dialling In (or DDI for short) is used when lines are connected to a PBX to allow incoming calls to be routed directly to an extension by dialling the appropriate number. This is instead of the caller having to dial a switchboard operator and being transferred through to the person / department they are calling.

DDI is available on analogue, ISDN2 or ISDN30 lines. DDI number ranges are allocated in blocks of 100 for analogue and blocks of 10 numbers for ISDN lines. Each extension then has a specific number from this range.

Structure is dependant on whether or not DDI is required on analogue, ISDN2 or ISDN30 lines.
In the case of analogue lines utilising DDI, a technical / management connection fee and annual rental charge are raised for this service. A management / data charge is also incurred on initial application for DDI. There is a further management connection charge and connection and rental charges for additional blocks of DDI numbers requested.
For DDI over ISDN an initial set up charge is raised together with connection and rental charges per block of 10 DDI numbers requested.
For DDI on ISDN30 the first 10 DDI numbers per channel are provided free. As an example, if a customer orders 20 channels of ISDN30 they are entitled to upto 200 DDI numbers free of the DDI connection and rental charges. The initial DDI set up charge would still apply.
Alternatively, if the customer ordered 20 channels of ISDN30 and requests 300 DDI numbers they will be entitled to 200 DDI numbers free of DDI connection and rental charges but the final 100 DDI numbers would incur DDI connection and rental charges at the appropriate rate per block of 10 numbers.

Service 01/04/08	Connection Charge		Annual Rental
Service 01/04/08	Exc. VAT	Inc. VAT	Exc. VAT	Inc. VAT
DDI via PSTN (analogue)
Technical / Management charge per installation	£1,750.00	£2,056.25	£1,080.00	£1,269.00
DDI Exchange Line	£140.00	£164.50	£126.12	£148.19
Management / Data Build Charge per 100 Numbers	£360.00	£423.00	£360.00	£423.00
Subsequent Data Build charge for additional numbers allocated	£710.00	£834.25	N/A
Each additional 100 Numbers allocated at the same time.	£360.00	£423.00	£360.00	£423.00
DDI over ISDN 2
Management Charge	£180.00	£211.50	N/A
DDI per 10 numbers	£36.00	£42.30	£48.00	£56.40
DDI over ISDN 30
Per number range	£210.00	£246.75	N/A
10 DDI numbers per ISDN 30 channel (free)	£0.00		£0.00
Additional 10 DDI numbers (provided in blocks of 10)	£11.00	£12.93	£42.00	£49.35
Number reservation (per block of 10)	N/A		£42.00	£49.35
DDI Number Break - Out*	£36.00	£42.30	£48.00	£56.40