ECMA 191 : 2ED 97

1 Scope
2 Conformance
3 References (normative)
4 Definitions
  4.1 External definitions
  4.2 Other definitions
      4.2.1 Additional network feature
      4.2.2 Automatic call offer invocation timer
      4.2.3 Busy
      4.2.4 Call, basic call
      4.2.5 Consultation timer
      4.2.6 Offered call
      4.2.7 Path retention
5 Acronyms
6 SS-CO stage 1 specification
  6.1 Description
      6.1.1 General description
      6.1.2 Qualifications on applicability to
             telecommunication services
  6.2 Procedures
      6.2.1 Provision/withdrawal
      6.2.2 Normal procedures
      6.2.3 Exceptional procedures
  6.3 Interactions with other supplementary services and ANFs
      6.3.1 Calling Line Identification Presentation (SS-CLIP)
      6.3.2 Connected Line Identification Presentation (SS-COLP)
      6.3.3 Calling/Connected Line Identification Restriction
             (SS-CLIR)
      6.3.4 Calling Name Identification Presentation (SS-CNIP)
      6.3.5 Connected Name Identification Presentation (SS-CONP)
      6.3.6 Calling/Connected Name Identification Restriction
             (SS-CNIR)
      6.3.7 Completion of Calls to Busy Subscriber (SS-CCBS)
      6.3.8 Completion of Calls on No Reply (SS-CCNR)
      6.3.9 Call Transfer (SS-CT)
      6.3.10 Call Forwarding Unconditional (SS-CFU)
      6.3.11 Call Forwarding Busy (SS-CFB)
      6.3.12 Call Forwarding No Reply (SS-CFNR)
      6.3.13 Call Deflection (SS-CD)
      6.3.14 Path Replacement (ANF-PR)
      6.3.15 Do Not Disturb (SS-DND)
      6.3.16 Do Not Disturb Override (SS-DNDO)
      6.3.17 Call Intrusion (SS-CI)
  6.4 Interworking considerations
  6.5 Overall SDL
7 SS-CO stage 2 specification
  7.1 Functional model
      7.1.1 Functional model description
      7.1.2 Description of functional entities
      7.1.3 Relationship of functional model to basic call
             functional model
  7.2 Information flows
      7.2.1 Definition of information flows
      7.2.2 Relationship of information flows to basic call
             information flows
      7.2.3 Examples of information flow sequences
  7.3 Functional entity actions
      7.3.1 Functional entity actions of FE1
      7.3.2 Functional entity actions of FE2
  7.4 Functional entity behaviour
      7.4.1 Behaviour of FE1
      7.4.2 Behaviour of FE2
  7.5 Allocation of functional entities to physical equipment
  7.6 Interworking considerations

Defines the Call Offer supplementary service (COSS) applying to various basic services supported by Private Integrated Services Networks (PISNs). This is a supplementary service enabling a call to be offered to a busy called user on request from the calling user (or on their behalf), and to wait for the acceptance of the call by the called user.