Downloaded 16 Jan 2002 Service Provider Interface Functional Requirements Phase 1

 

SPIG

Service Provider Interface Functional Requirements

Phase 1

Output document of the Technical Interfaces working Group of the UK Service Providers Interest Group of the NICC

February 1998

 

 

Working Group Chairman: Peter Randall, Telinco

 

Introduction

This document is based on the earlier document:-

"Output from SP/PTO Technical Interface Study Group for Consideration by ISC Ranked Priorities (switched telephony) for Consideration by ISC - Issued after comments from Study Group Date: 23rd September 1997"

At the request of the PNO-ISC working party on SP interfaces further detail and explanation has been added to the requirements at a meeting on 20/11/97 between Ashley Mirfin (Cellcom), David Stanfield (INMS), Keith Morrill (BT) and Rob Spindley (BT). The name of the requirement and its high level description are reproduced from the earlier document.

Draft A of this document was discussed at the SP/PTO Technical Interface Study Group on 3 December. Draft B included comments made at that meeting and it was discussed at the meeting on 13 January in order to agree the document for release to PNO-ISC. Draft C was produced as a result of the comments received from the meeting on the 13th January and it is now issued as Version 1 following the meeting on 9th February 1998 at Oftel.

 

Requirements

1. Receipt of CLIs by the Service Provider, including withheld CLIs.

1.1. High Level Description - Importance A, Urgent
Circuit switched calls delivered to service providers are required to include the identity of the line from which the call is originated. This applies to CLIs marked as with-held. The type of CLIs required (network, presentation etc.) requires further discussion.

1.2. Details and Explanation
The Network CLI must be available to the SP and this must unambiguously identify the calling line (User-Network Interface). This CLI must therefore be accepted as valid by the originating network (but note that it may have been provided by another Service Provider, as detailed in 2.2). Note that the originating access will need the ability to provide the network with the extension number digits where appropriate. This CLI is required in order, for example, to perform geographic based routing or originating line verification.

 

2. Population of CLIs by the SP in outgoing calls from the SP

2.1. High Level Description - Importance A, Urgent
Circuit switched calls originated from, or dropped back from, SP to contain the CLI of the originating caller to be delivered to the called line.
Malicious call identification must be considered e.g. the ability to carry the SP’s CLI to the destination exchange and validation of CLIs.
Marking of CLI must be considered, e.g. Presentation CLI, User Provided, Network Provided, Screened, etc.

2.2. Details and Explanation
The SP must be able to provide the network with a CLI for delivery to the destination for presentation purposes at the called customer. This is to enable the called party to receive, for example, the original callers CLI. The SP may also wish to originate "unsolicited calls" and provide an appropriate CLI for display.

 

3. An indication to the SP of a call attempt by a customer of the SP and having received that indication, the SP can then determine how that call is routed

3.1. High Level Description - Importance A, Urgent
1. Circuit related (CR).
e.g. When an SP’s customer goes on-line (off hook), a circuit switched call is automatically set up to the SP.
2. Non-circuit related (NCR).
When an SP’s customer goes on-line, a request for instructions is sent to the SP containing details such as CLI.
Comments:-
Access to emergency services and Government Telephone Preference Scheme must be considered.

3.2. Details and Explanation
For a circuit related SP i/f there are no signalling issues although there are OSS implications for setting the appropriate data against the calling line. For non-circuit related a signal is required to inform the SP that one of his customers wishes to initiate a call. The network may be required to "trap" certain calls e.g. emergency calls, rather than indicating the call attempt to the SP. The ability to send the signal after the customer has dialled (off hook + analysed info) is required. For CR and NCR the SP will provide the network with a new number which could include the destination number and also digits to determine the network through which the call is routed.

 

4. An indication to the SP that someone has dialled one of the SP’s customers and having received that indication, the SP can then determine how that call is routed. The number dialled to be either an individual number or a number block.

4.1. High Level Description - Importance A, Urgent
1. Circuit related.
When a call destined for an SP's customer is identified, a circuit switched call is set up to the SP.
2. Non-circuit related.
When a call destined for a SP’s customer is identified, a request for instructions is sent to the SP

4.2. Details and Explanation
This requirement applies to customers with ordinary geographic numbers (initially excluding extension number digits though eventually based on the full DDI number) and not special e.g. 07, numbers. For CR there are no signalling implications beyond those in 1. For NCR the requirements is to provide an indication that a call is destined for an SP customer’s line, before applying ringing. This could be done by analysing the digits dialled prior to the call arriving at the destination exchange or by detecting that a call has arrived at the customer’s line, this might be achieved by an interaction between the network and PBX prior to call delivery. For CR and NCR the SP will provide the network with a new number which could include the destination number and also digits to determine the network through which the call is routed.

 

5. Access to various IN-type triggers and events, e.g. Ring No-Reply etc.

5.1. High Level Description - Importance A, Urgent
1.Circuit related. Indication of e.g. busy or no reply, for a call incoming to an SP customer’s line.
SP originated circuit switched calls are also required to provide indication of e.g. ringing, answer, busy, number unobtainable and call cleardown.
2. Non-circuit related.
Calls routed in response to instructions from an SP require the ability to request instructions from the SP when ringing no reply or busy are encountered, and notify occurrence of answer, number unobtainable and call cleardown.
Comments:-
Call charging and billing must be considered.

5.2. Details and Explanation
The SP requires an indication if a call is not answered successfully by an SP’s customer e.g. busy or no reply and call clear down. This indication is required before tones other than ringing are returned to the caller. The SP will then return instructions as to how the call should be handled. For CR the call would be transferred to the SP, for NCR a signal is sent to the SP requesting instructions.

 

6. On-line message waiting indication.
Note - as an expedient solution is to be provided (i.e. Call Mapping) based on DPNSS then meeting this requirement should not delay the provision of solutions to the other requirements. However in the longer term a replacement for the expedient solution will be required.

6.1. High Level Description - Importance A, Urgent
SP is provided with the ability to remotely control message waiting indication on its customers’ lines.

6.2. Details and Explanation
Ideally it should not be necessary for the SP to set up a call to the network to achieve this requirement.

 

7. Ability to direct routing and destinations of calls.

7.1. High Level Description - Importance A, Urgent
Provide call destination and routing information e.g. specific network to be used.
Comments:-
Routings may not be allowed to certain destinations.
Call charging and billing must be considered.

7.2. Details and Explanation
This requirement applies to calls from any customer who dials an SP customer identified by a non geographic (but not mobile) number e.g. 08xxxx, 07xxxxx. For CR the call is routed to the relevant SP. For NCR a signal is sent to the SP to request instructions for handling the call. For CR and NCR the SP will provide the network with a new number which could include the destination number and also digits to determine the network through which the call is routed.

 

8. Interrogation of an SP customer’s NTP for delivery / collection of telemetry.

8.1. High Level Description - Importance B, Urgent
Example implementation could be no-ring calls.

8.2. Details and Explanation
The SP requires to send data to or receive data from an NTP without alerting the customer. In the longer term it should be possible to do this without setting up a call across the network(s). Note that different solutions may be applicable to ISDN destinations. A CPE solution may be possible based on the NTP recognising the SP’s CLI in an incoming call and answering this itself.

 

9. Route optimisation

9.1. High Level Description - Importance B, Less Urgent
SP drops back call to network.
Network drops back call to originating point (could be on another network).
Comments:-
Drop back may not be allowed to certain destinations.
Call charging and billing must be considered.

9.2. Details and Explanation
The route optimisation (e.g. call drop back) is after answer by the SP e.g. in order to collect MF digits. The originating point is the originating DLE.

 

10. Supervision of dropped-back calls.

10.1. High Level Description - Importance C, Least Urgent
e.g. Indication of engaged, no answer, follow-on call, clear down. Note that the dropped back call could be within a different network to that which the SP is connected.

10.2. Details and Explanation
When using an NCR interface calls are not "dropped back" but are set up according to instructions provided by the SP. These instructions could include request for notification of events such as no answer.

With a CR interface once the call has been dropped back the SP is no longer in the call path and major enhancements would be needed to re-establish the call to the SP if it did not complete.

 

11. Ability to receive MF digits before answer.

11.1. High Level Description - Importance D, Least Urgent
MF digits could be available only after answer and be dependent on the originating terminal, this is not considered to be a problem hence "least urgent" marking.

11.2 Details and Explanation
With ISDN a forward path is not switched through until answer.

 

12. Ability to receive originally dialled digits.

12.1. High Level Description - Importance D, Least Urgent
Originally dialled number is to be passed to the SP.

12.2. Details and Explanation
The SP requires to know the original number which was dialled in the case, for example, of an 08xxx or 07xxx number. Could be a similar solution to Non-Geographic Number Portability (NGNP) for CR. NCR would include original number in signalling message requesting instructions. If multiple SPs are involved in a call then it should be possible for each of them to receive the original dialled digits.

Footnote:

'It should be noted that the task group is not specifically considering Operational Support System (OSS) interfaces. It is assumed that any 'unbundled' network capabilities offered by a network operator, will be supported by the OSS interface(s) necessary to enable their viable usage (e.g. configuration control, network usage information, statistics, provision and repair management, etc.) by ISPs.'

End of Document.

Downloaded 16 Jan 2002