1、 Problem Solvers to the Telecommunications Industry TECHNICAL REPORT T1.TR.69-2000 Technical Report on Signaling Requirements for the Support of Narrowband Services Via Broadband Transport Technologies Prepared by T1S1.7 Working Group on Services, Architecture, and Control 1 A Word from ATIS and Com
2、mittee T1 Established in February 1984, Committee T1 develops technical standards, reports and requirements regarding interoperability of telecommunications networks at interfaces with end-user systems, carriers, information and enhanced-service providers, and customer premises equipment (CPE). Comm
3、ittee T1 is sponsored by ATIS and is accredited by ANSI. T1.TR.69-2000 Published by Alliance for Telecommunications Industry Solutions 1200 G Street, NW, Suite 500 Washington, DC 20005 Committee T1 is sponsored by the Alliance for Telecommunications Industry Solutions (ATIS) and accredited by the Am
4、erican National Standards Institute (ANSI). Copyright 2001 by Alliance for Telecommunications Industry Solutions All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. For
5、information contact ATIS at 202.628.6380. ATIS is online at . Printed in the United States of America. T1.TR.69-2000 i Technical Report No. 69 Signaling Requirements for the Support of Narrowband Services Via Broadband Transport Technologies Abstract This T1 technical report presents the procedures,
6、 information flows and information elements needed for supporting narrowband services via broadband transport technologies. The report provides requirements for the support of narrowband services via broadband transport technologies. Its scope is limited to functionality of the Serving Node (SN) and
7、 associated protocols at the call control and bearer control levels needed to provide this capability across an ATM backbone network for Capability Set 1 (CS 1). Document T1.TR.69-2000 Prepared by T1S1.7 Working Group on Services, Architecture, and Control T1.TR.69-2000 ii Foreword This T1 Technical
8、 Report (TR) presents the procedures, information flows, and information elements needed for supporting narrowband services via broadband transport technologies. The report provides requirements for the support of narrowband services via broadband transport technologies. Its scope is limited to func
9、tionality of the Serving Node (SN) and associated protocols at the call control and bearer control levels needed to provide this capability across an ATM backbone network for Capability Set 1 (CS 1). Footnotes and informative annexes are not officially part of this TR. Suggestions for improvement of
10、 the TR are welcome and should be sent to the Alliance for Telecommunications Industry Solutions - Committee T1 Secretariat, 1200 G Street N.W., Suite 500, Washington, DC 20005. This TR was developed in Technical Subcommittee T1S1 on Services, Architectures BCF-G, BCF-N, BCF-R and BCF-T. The Bearer
11、Control Nodal Function (BCF-G) provides the control of the bearer switching function, the communication capability with its associated call service function (CSF-G), and the signaling capability necessary to establish and release of the backbone network connection. The Bearer Control Nodal Function
12、(BCF-N) provides the control of the bearer switching function, the communication capability with its associated call service function (CSF), and the signaling capability necessary to establish and release of the backbone network connection to its peer (BCF-N). The Bearer Control Relay Function (BCF-
13、R) provides the control of the bearer switching function and relays the bearer control signaling requests to next BCF in order to complete the edge to edge backbone network connection The Bearer Control Nodal Function (BCF-T) provides the control of the bearer switching function, the communication c
14、apability with its associated call service function (CSF-T), and the signaling capability necessary to establish and release of the backbone network connection. Bearer Control Segment (BCS): Represents the signaling relationship between two adjacent Bearer Control Functional entities (BCF). Bearer I
15、nter-Working Function (BIWF): A functional entity, which provides bearer control and media mapping/switching functions within the scope of an Interface Serving Node (ISN). A BIWF contains one Bearer Control Nodal Function (BCF-N). Call Control Association (CCA): Represents the signaling association
16、between two adjacent Call Service Functional entities (CSF). Call Service Function (CSF): Note that four types of CSFs are illustrated in the above functional model, CSF-N, CSF-T, CSF-G, and CSF-C. The Call Service Nodal Function (CSF-N) provides the service control nodal actions associated with the
17、 narrowband service by inter-working with narrowband and Bearer Independent Call Control (BICC) signaling, signaling to its peer (CSF-N) the characteristics of the call, and invoking the Bearer Control Nodal Functions (BCF-N) necessary to transport the narrowband bearer service across the broadband
18、backbone network. The Call Service Transit Function (CSF-T) provides the service transit actions necessary to establish and maintain a backbone network call and its associated bearer by relaying signaling between CSF-N peers and invoking the Bearer Control Nodal Functions (BCF-T) necessary to transp
19、ort the narrowband bearer service across the broadband backbone network. The Call Service Gateway Function (CSF-G) provides the service gateway actions necessary to establish and maintain a backbone network call and its associated T1.TR.69-2000 5 bearer by relaying signaling between CSF-N peers and
20、invoking the Bearer Control Nodal Functions (BCF-N) necessary to transport the narrowband bearer service between broadband backbone networks. The Call Service Coordination Function (CSF-C) provides the call coordination and mediation actions necessary to establish and maintain a backbone network cal
21、l by relaying signaling between CSF-N peers. The CSF-C has no association with any BCF. It is only a call control function. Call Mediation Node (CMN): A functional entity, which provides CSF-C, functions without an associated BCF entity. Interface Serving Node (ISN): A functional entity, which provi
22、des the interface with the ISDN networks. This functional entity contains one or more call service nodal functions (CSF-N), and one or more inter-working functions (BIWF) that interact with the ISDN and its peers within the broadband backbone network. Gateway Serving Node (GSN): A functional entity,
23、 which provides gateway functionality between two network domains. This functional entity contains one or more call service gateway functions (CSF-G), and one or more bearer inter-working functions (BIWF). GSNs interact with other GSNs, in other broadband backbone network domains and other ISNs and
24、TSNs within its own broadband backbone network domain. The network signaling flows for a GSN are equivalent as those for a TSN. Network Bearer Connection (NBC): Is used to transport a user selected bearer service between two or more Terminal Equipment (TE). Serving Node (SN): A generic term referrin
25、g to ISN, GSN or TSN nodes. Switching Node (SWN): A functional entity, which provides the switching, functions within the broadband backbone network. This functional entity contains a bearer control state machine (BCF-R). SWNs interact with other SWNs, within their own broadband backbone network dom
26、ain. The SWNs BCF-R also interact with the BCF-N functions contained in BIWF entities. Terminal Equipment (TE): Represents the customers access equipment used to request and terminate network associated connectivity services. Transit Serving Node (TSN): A functional entity, which provides transit fu
27、nctionality between ISNs and GSNs. This functional entity contains one or more call service transit functions (CSF-T), and one or more bearer inter-working functions (BIWF). TSNs interact with other TSNs, GSNs and ISNs within their own broadband backbone network domain. 3.2 Definition of Signaling F
28、low Objects The following objects are the signaling objects to be carried in the information flow procedure definitions. These objects will be used in the set of information flows contained in this document. (BCS-ID) Bearer Control Segment ID: Identifies the signaling association between two logical
29、ly adjacent bearer control entities. (BNC Characteristics) Backbone Network Connect Characteristics: Identifies the selected BNC type (i.e., AAL1 or AAL2). (BNC-ID) Backbone Network Connection ID: This signaling object generically equates to the Virtual Channel Connection Identifier (VCCI) if an ATM
30、 Virtual Channel connection is established between ISNs or an AAL Type 2 Connection Identifier if an AAL Type 2 connection is established between ISNs. This identifier represents the relationship between pair BNCeps. (BNCL-ID) Backbone Network Connection Link ID: Identifies the transport link betwee
31、n two SWNs, or between a SWN and a BIWF. This identifier represents the relationship between a BNCep and a BNCrp or in trunking configurations a pair of BNCeps. T1.TR.69-2000 6 Bearer Service Characteristics: This signaling object specifies the user specified bearer service that shall be provided be
32、tween the requesting user and the terminating user. This signaling object is contained in the initial service request received from the requesting user and is carried within the initial service requests between network nodes and the terminating user. (Called-Party-Addr) Called Party Address: The add
33、ress of the called user. (Calling-Party-Addr) Calling Party Address: The address of the calling user. (CCA-ID) Call Control Association ID: Identifies the signaling association between two logically adjacent call control entities (between CSF-Ns). In ISDN this is a CIC. (CSF-Addr) Call Service Funct
34、ion Address: Identifies the address of CSF-N within the requesting ISN entity. This is the Point Code used by MTP to identify originating and destination CSF-Ns within ISNs. (T-BIWF-Addr) Terminating Inter-Working Function Address: Identifies the address of the BCF-N within the terminating BIWF. At
35、the bearer level similar to the called party address. (O-BIWF-Addr) Originating Inter-Working Function Address: Identifies the address of the BCF-N within the originating BIWF. At the bearer level similar to the calling party address. Action Indicator: An extended control object, indicating the requ
36、ested action to be taken at a subsequent SN or an action performed at a previous SN. Bearer Service Characteristics: Specifies the user requested bearer service. Example values are voiceband services, and circuit mode data. This object equates to the resource component. TABLE 1-1 Mapping of Signalin
37、g Object to Call Release of a call and related bearer, Release of the call only, and Release of an idle bearer not associated with any call. 6.4 Error Handling Separate error handling shall be the responsibility of the call and bearer protocols. Interactions between these protocols shall also be cov
38、ered. 6.5 Echo Control Procedure Only basic echo control procedures are required for CS 1. Enhanced echo control and dynamic echo control procedures are not required for CS 1. Echo control procedures are defined in ITU-T Rec. Q.115. Enhanced/dynamic echo control parameters received at the ISDN/ISN i
39、nterface must be passed unmodified by the call control protocol. 6.6 Blocking and Unblocking Blocking and unblocking of backbone network connections shall be support. BNC resource blocking and unblocking shall be handled by BNC control. 6.7 Call Automatic Repeat Attempts The application of call auto
40、matic repeat attempt shall be support in CS 1. 6.8 Dual Seizure Dual seizure should be minimized and the recovery from dual seizure of signaling identifiers when they occur shall be to be supported in CS 1. 6.9 Reset The reset of call and bearer resources shall be handled by the respective control p
41、rotocol. 6.10 Support of Codec Negotiation Provide functionality to convey codec information to all nodes with coding/transcoding functionality. Capability to negotiate among all SN with coding/transcoding functionality with common codec to be used for a specific call. Idle backbone network connecti
42、on shall not be used when codec negotiation is requested. 6.11 Support of Codec Modification Provide functionality to modify the codec selected. Provide functionality to request codec modification from either end of the BNC connection. 7. General Signaling Transport Requirements Figure 7-1 shows the
43、 signaling transport architecture that provides signaling transport independence by using signaling converters. T1.TR.69-2000 13 Primitives PrimitiveCall Control Signaling Call Control Signaling Generic Primitives Generic Primitives Specific Primitives Specific Primitives Signaling Signaling Transpo
44、rt Converter Transport Converter Signaling Transport Signaling Transport Call Control signaling messages Figure 7-1 Signaling Transport Architecture Signaling Transport Converter entity operations may include: Passing parameters from the generic primitives to the specific primitives and vice versa A
45、dding parameters to specific primitives issued and ignoring parameters from specific primitives received Issuing specific primitives upon receiving specific primitives without any action on the generic interface, etc. The call signaling protocol entity has BICC functionality. The signaling transport
46、 entity is the provider of the real signaling transport. The generic primitive interface includes signaling transport independent primitives. The specific primitives interface includes signaling transport dependent primitives. 8. Backbone Network Signaling Flows The method of documenting the signali
47、ng flows involves the definition of a set of information flow names. The following guidelines on defining a set of flow are to use explicit protocol message names for the call control information and use protocol independent information flows for the bearer level. The following naming convention is:
48、 Call control information flow names = ISUP protocol message names. Bearer control information flow names = protocol independent names as follows: Bearer Setup Request: used to request the establishment of a bearer. Bearer Setup Connect: used to indicate the completion of the bearer setup. Bearer Se
49、tup Reject: used to indicate unsuccessful bearer setup. T1.TR.69-2000 14 Bearer Release Request: used to request the release of a bearer. Bearer Release Acknowledge: used to indicate completion of the bearer release. The information flow diagram template to be used in the construction of information flows is contained in Figure 8-1. Note that information flows between call control entities and bearer control entities are shown as dashed arrows in the diagram. These flows would be considered to be in
