RFC 3868
Signalling Connection Control Part User Adaptation Layer (SUA)
Pages: 131
Proposed Standard
Proposed Standard
Part 1 of 5 – Pages 1 to 19
Network Working Group J. Loughney, Ed. Request for Comments: 3868 Nokia Category: Standards Track G. Sidebottom Signatus Technologies L. Coene G. Verwimp Siemens n.v. J. Keller Tekelec B. Bidulock OpenSS7 Corporation October 2004 Signalling Connection Control Part User Adaptation Layer (SUA) Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2004).Abstract
This document defines a protocol for the transport of any Signalling Connection Control Part-User signalling over IP using the Stream Control Transmission Protocol. The protocol is designed to be modular and symmetric, to allow it to work in diverse architectures, such as a Signalling Gateway to IP Signalling Endpoint architecture as well as a peer-to-peer IP Signalling Endpoint architecture.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Scope. . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Abbreviations and Terminology. . . . . . . . . . . . . . 4 1.3. Signalling Transport Architecture. . . . . . . . . . . . 6 1.4. Services Provided by the SUA Layer . . . . . . . . . . . 9 1.5. Internal Functions Provided in the SUA Layer . . . . . . 11 1.6. Definition of SUA Boundaries . . . . . . . . . . . . . . 14 2. Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . 19 3. Protocol Elements. . . . . . . . . . . . . . . . . . . . . . . 19 3.1. Common Message Header. . . . . . . . . . . . . . . . . . 20 3.2. SUA Connectionless Messages. . . . . . . . . . . . . . . 24 3.3. Connection Oriented Messages . . . . . . . . . . . . . . 27 3.4. Signalling Network Management (SNM) Messages . . . . . . 42 3.5. Application Server Process State Maintenance Messages. . 49 3.6. ASP Traffic Maintenance Messages . . . . . . . . . . . . 53 3.7. SUA Management Messages. . . . . . . . . . . . . . . . . 56 3.8. Routing Key Management (RKM) Messages. . . . . . . . . . 58 3.9. Common Parameters. . . . . . . . . . . . . . . . . . . . 61 3.10. SUA-Specific parameters. . . . . . . . . . . . . . . . . 74 4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.1. Procedures to Support the SUA-User Layer . . . . . . . . 92 4.2. Receipt of Primitives from the Layer Management. . . . . 93 4.3. AS and ASP State Maintenance . . . . . . . . . . . . . . 95 4.4. Routing Key Management Procedures. . . . . . . . . . . .109 4.5. Availability and/or Congestion Status of SS7 Destination Support101 . . . . . . . . . . . . . . . . .112 4.6. MTP3 Restart . . . . . . . . . . . . . . . . . . . . . .115 4.7. SCCP - SUA Interworking at the SG. . . . . . . . . . . .115 5. Examples of SUA Procedures . . . . . . . . . . . . . . . . . .117 5.1. SG Architecture. . . . . . . . . . . . . . . . . . . . .117 5.2 IPSP Examples. . . . . . . . . . . . . . . . . . . . . .119 6. Security Considerations. . . . . . . . . . . . . . . . . . . .121 7. IANA Considerations. . . . . . . . . . . . . . . . . . . . . .121 7.1. SCTP Payload Protocol ID . . . . . . . . . . . . . . . .121 7.2. Port Number. . . . . . . . . . . . . . . . . . . . . . .121 7.3. Protocol Extensions. . . . . . . . . . . . . . . . . . .121 8. Timer Values . . . . . . . . . . . . . . . . . . . . . . . . .123 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .123 10. References . . . . . . . . . . . . . . . . . . . . . . . . . .123 10.1. Normative References . . . . . . . . . . . . . . . . . .123 10.2. Informative References . . . . . . . . . . . . . . . . .124
Appendix A. Signalling Network Architecture . . . . . . . . . . .125 A.1. Generalized Peer-to-Peer Network Architecture. . . . . .125 A.2. Signalling Gateway Network Architecture. . . . . . . . .126 A.3. Signalling Gateway Message Distribution Recommendations. . . . . . . . . . . . . . . . . . . . .128 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .129 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . .1311. Introduction
There is ongoing integration of switched circuit networks and IP networks. Network service providers are designing IP-based signalling architectures that need support for SS7 and SS7-like signalling protocols. IP provides an effective way to transport user data and for operators to expand their networks and build new services. In these networks, there is need for interworking between the SS7 and IP domains [2719]. This document defines a protocol for the transport SS7 SCCP-User protocols [ANSI SCCP] [ITU SCCP], such as TCAP and RANAP, over IP using the Stream Control Transmission Protocol (SCTP) [2960].1.1. Scope
This document details the delivery of SCCP-user messages (MAP & CAP over TCAP [ANSI TCAP] [ITU TCAP], RANAP [RANAP], etc.) messages over IP between two signalling endpoints. Consideration is given for the transport from a signalling gateway to an IP signalling node (such as an IP-resident Database) as described in the Framework Architecture for Signalling Transport [2719]. This protocol can also support transport of SCCP-user messages between two endpoints wholly contained within an IP network. The delivery mechanism addresses the following criteria: * Support for transfer of SCCP-User Part messages * Support for SCCP connectionless service. * Support for SCCP connection oriented service. * Support for the operation of SCCP-User protocol peers. * Support for the management of SCTP transport associations between signalling gateways and IP-based signalling nodes. * Support for distributed IP-based signalling nodes. * Support for the asynchronous reporting of status changes to management functions.
1.2. Abbreviations and Terminology
1.2.1. Abbreviations
CAP - CAMEL Application Protocol. GTT - Global Title Translation. MAP - Mobile Application Protocol. PC - Signalling System no. 7 Point Code. RANAP - Radio Access Network Application Protocol. SCTP - Stream Control Transmission Protocol. SS7 - Signalling System no. 7. TCAP - Transaction Capabilities Application Protocol.1.2.2. Terminology
Signalling Gateway (SG) - Network element that terminates switched circuit networks and transports SCCP-User signalling over IP to an IP signalling endpoint. A Signalling Gateway could be modeled as one or more Signalling Gateway Processes, which are located at the border of the SS7 and IP networks. Where an SG contains more than one SGP, the SG is a logical entity and the contained SGPs are assumed to be coordinated into a single management view to the SS7 network and to the supported Application Servers. Application Server (AS) - A logical entity serving a specific Routing Key. An example of an Application Server is a virtual IP database element handling all requests for an SCCP-user. The AS contains a set of one or more unique Application Server Processes, of which one or more is normally actively processing traffic. Application Server Process (ASP) - An Application Server Process serves as an active or backup process of an Application Server (e.g., part of a distributed signalling node or database element). Examples of ASPs are MGCs, IP SCPs, or IP-based HLRs. An ASP contains an SCTP endpoint and may be configured to process traffic within more than one Application Server. IP Server Process (IPSP) - A process instance of an IP-based application. An IPSP is essentially the same as an ASP, except that it uses SUA in a peer-to-peer fashion. Conceptually, an IPSP does not use the services of a Signalling Gateway.
Signalling Gateway Process (SGP) - A process instance of a Signalling Gateway. It serves as an active, load-sharing or broadcast process of a Signalling Gateway. Signalling Process - A process instance that uses SUA to communicate with other signalling process. An ASP, a SGP and an IPSP are all signalling processes. Association - An association refers to an SCTP association. The association provides the transport for the delivery of SCCP-User protocol data units and SUA layer peer messages. Routing Key - The Routing Key describes a set of SS7 parameters and/or parameter ranges that uniquely defines the range of signalling traffic configured to be handled by a particular Application Server. An example would be where a Routing Key consists of a particular SS7 SCCP SSN plus an identifier to uniquely mark the network that the SSN belongs to, for which all traffic would be directed to a particular Application Server. Routing Keys are mutually exclusive in the sense that a received SS7 signalling message cannot be directed to more than one Routing Key. Routing Keys can be provisioned, for example, by a MIB or registered using SUA's dynamic registration procedures. Routing keys MUST NOT span multiple network appearances. Routing Context - An Application Server Process may be configured to process traffic within more than one Application Server. In this case, the Routing Context parameter is exchanged between the SGP and the ASP (or between two ASPs), identifying the relevant Application Server. From the perspective of an SGP/ASP, the Routing Context uniquely identifies the range of traffic associated with a particular Application Server, which the ASP is configured to receive. There is a 1:1 relationship between a Routing Context value and a Routing Key within an AS. Therefore the Routing Context can be viewed as an index into an AS Table containing the AS Routing Keys. Address Mapping Function (AMF) - The AMF is an implementation dependent function that is responsible for resolving the address presented in the incoming SCCP/SUA message to correct SCTP association for the desired endpoint. The AMF MAY use routing context / routing key information as selection criteria for the appropriate SCTP association. Fail-over - The capability to reroute signalling traffic as required to an alternate Application Server Process, or group of ASPs, within an Application Server in the event of failure or unavailability of a currently used Application Server Process. Fail-over may apply upon the return to service of a previously unavailable Application Server Process.
Host - The computing platform that the SGP or ASP process is running on. Layer Management - Layer Management is a nodal function that handles the inputs and outputs between the SUA layer and a local management entity. Network Appearance - The Network Appearance is an SUA local reference (typically an integer) shared by SG and AS that together with a Signalling Point Code uniquely identifies an SS7 node by indicating the specific SS7 network it belongs to. Network Byte Order - Most significant byte first, a.k.a. Big Endian. Stream - A stream refers to an SCTP stream; a unidirectional logical channel established from one SCTP endpoint to another associated SCTP endpoint, within which all user messages are delivered sequenced except for those submitted to the unordered delivery service. Transport address - an address that serves as a source or destination for the unreliable packet transport service used by SCTP. In IP networks, a transport address is defined by the combination of an IP address and an SCTP port number. Note, only one SCTP port may be defined for each endpoint, but each SCTP endpoint may have multiple IP addresses.1.3. Signalling Transport Architecture
The framework architecture that has been defined for switched circuit networks signalling transport over IP [2719] uses multiple components, including an IP transport protocol, a signalling common transport protocol and an adaptation module to support the services expected by a particular switched circuit networks signalling protocol from its underlying protocol layer. In general terms, the SUA architecture can be modeled as a peer-to- peer architecture. The first section considers the SS7 to IP interworking architectures for connectionless and connection-oriented transport. For this case, it is assumed that the ASP initiates the establishment of the SCTP association with SG.1.3.1. Protocol Architecture for Connectionless Transport
In this architecture, the SCCP and SUA layers interface in the SG. Interworking between the SCCP and SUA layers is needed to provide for the transfer of the user messages as well as the management messages.
******** SS7 *************** IP ********
* SEP *---------* *--------* *
* or * * SG * * ASP *
* STP * * * * *
******** *************** ********
+------+ +------+
| SUAP | | SUAP |
+------+ +------+------+ +------+
| SCCP | | SCCP | SUA | | SUA |
+------+ +------+------+ +------+
| MTP3 | | MTP3 | | | |
+------+ +------+ SCTP | | SCTP |
| MTP2 | | MTP2 | | | |
+------+ +------+------+ +------+
| L1 | | L1 | IP | | IP |
+------+ +------+------+ +------+
| | | |
+---------------+ +------------+
SUAP - SCCP/SUA User Protocol (TCAP, for example)
STP - SS7 Signalling Transfer Point
See Appendix A.3.1 for operation recommendations.
1.3.1.1. SG as endpoint
In this case, the connectionless SCCP messages are routed on point
code (PC) and subsystem number (SSN). The subsystem identified by
SSN and Routing Context is regarded as local to the SG. This means
from SS7 point of view, the SCCP-user is located at the SG.
1.3.1.2. Signalling Gateway as relay-point
A Global Title translation is executed at the signalling gateway,
before the destination of the message can be determined. The actual
location of the SCCP-user is irrelevant to the SS7 network. GT
Translation yields an "SCCP entity set", from which an Application
Server can be derived. Selection of the Application Server is based
on the SCCP called party address (and possibly other SS7 parameters
depending on the implementation).
1.3.2. Protocol Architecture for Connection-Oriented Transport
In this architecture, the SCCP and SUA layers share an interface in the signalling gateway process to associate the two connection sections needed for the connection-oriented data transfer between SEP and ASP. Both connection sections are setup when routing the Connect Request messages from the signalling end point via signalling gateway process to ASP and visa versa. The routing of the Connect Request message is performed in the same way as described in 1.3.1. ******** SS7 *************** IP ******** * SEP/ *---------* SG *--------* ASP * * STP * * * * * ******** *************** ******** +------+ +------+ | SUAP | | SUAP | +------+ +------+------+ +------+ | SCCP | | SCCP | SUA | | SUA | +------+ +------+------+ +------+ | MTP3 | | MTP3 | | | | +------| +------+ SCTP | | SCTP | | MTP2 | | MTP2 | | | | +------+ +------+------+ +------+ | L1 | | L1 | IP | | IP | +------+ +------+------+ +------+ | | | | +---------------+ +------------+ SUAP - SCCP/SUA Application Protocol (e.g., - RANAP/RNSAP) STP - SS7 Signalling Transfer Point See Appendix A.3.2 for operation recommendations.1.3.3. All IP Architecture
This architecture can be used to carry a protocol that uses the transport services of SCCP within an IP network. This allows flexibility in developing networks, especially when interaction between legacy signalling is not needed. The architecture removes the need for signalling gateway functionality.
******** IP ********
* IPSP *--------* IPSP *
******** ********
+------+ +------+
| SUAP | | SUAP |
+------+ +------+
| SUA | | SUA |
+------+ +------+
| SCTP | | SCTP |
+------+ +------+
| IP | | IP |
+------+ +------+
| |
+----------------+
SUAP - SCCP/SUA Application Protocol (e.g., - RANAP/RNSAP)
1.3.4. ASP Fail-over Model and Terminology
The SUA protocol supports ASP fail-over functions to support a high
availability of transaction processing capability.
An Application Server can be considered as a list of all ASPs
configured/registered to handle SCCP-user messages within a certain
range of routing information, known as a Routing Key. One or more
ASPs in the list may normally be active to handle traffic, while
others may be inactive but available in the event of failure or
unavailability of the active ASP(s).
For operation recommendations, see Appendix A.
1.4. Services Provided by the SUA Layer
1.4.1. Support for the transport of SCCP-User Messages
The SUA supports the transfer of SCCP-user messages. The SUA layer
at the signalling gateway and at the ASP support the seamless
transport of user messages between the signalling gateway and the
ASP.
1.4.2. SCCP Protocol Class Support
Depending upon the SCCP-users supported, the SUA supports the 4
possible SCCP protocol classes transparently. The SCCP protocol
classes are defined as follows:
* Protocol class 0 provides unordered transfer of SCCP-user messages
in a connectionless manner.
* Protocol class 1 allows the SCCP-user to select the sequenced
delivery of SCCP-user messages in a connectionless manner.
* Protocol class 2 allows the bidirectional transfer of SCCP-user
messages by setting up a temporary or permanent signalling
connection.
* Protocol class 3 allows the features of protocol class 2 with the
inclusion of flow control. Detection of message loss or mis-
sequencing is included.
Protocol classes 0 and 1 make up the SCCP connectionless service.
Protocol classes 2 and 3 make up the SCCP connection-oriented
service.
1.4.3. Native Management Functions
The SUA layer provides the capability to indicate errors associated
with the SUA-protocol messages and to provide notification to local
management and the remote peer as is necessary.
1.4.4. Interworking with SCCP Network Management Functions
SUA uses the existing ASP management messages for ASP status
handling. The interworking with SCCP management messages consists of
DUNA, DAVA, DAUD, DRST, DUPU or SCON messages (defined in section 3)
on receipt of SSP, SSA, SST or SSC (defined by SCCP) to the
appropriate ASPs. See also chapter 1.4.5. The primitives below are
sent between the SCCP and SUA management functions in the SG to
trigger events in the IP and SS7 domain.
Generic |Specific |
Name |Name |ANSI/ITU Reference
----------+-----------+---------------------------------------------
N-State |Request |ITU-Q.711 Chap 6.3.2.3.2 (Tab 16/Q.711)
|Indication |ANSI-T1.112 Chap 2.3.2.3.2 (Tab 8E/T1.112.1)
----------+-----------+---------------------------------------------
N-PCstate |Indication |ITU-Q.711 Chap 6.3.2.3.3 (Tab 1/Q.711)
| |ANSI-T1.112 Chap 2.3.2.3.4 (Tab 8G/T1.112.1)
----------+-----------+---------------------------------------------
N-Coord |Request |ITU-Q.711 Chap 6.3.2.3.1 (Tab 15/Q.711)
|Indication |ANSI-T1.112 Chap 2.3.2.3.3 (Tab 8F/T1.112.1)
|Response |
|Confirm |
1.4.5. Support for the management between the SGP and ASP.
The SUA layer provides interworking with SCCP management functions at the SG for operation between the switched circuit networks and the IP network. It should: * Provide an indication to the SCCP-user at an ASP that a SS7 endpoint/peer is unreachable. * Provide an indication to the SCCP-user at an ASP that a SS7 endpoint/peer is reachable. * Provide congestion indication to SCCP-user at an ASP. * Provide the initiation of an audit of SS7 endpoints at the SG.1.4.6. Relay function
For network scalability purposes, the SUA may be enhanced with a relay functionality to determine the next hop SCTP association toward the destination SUA endpoint. The determination of the next hop may be based on Global Title information (e.g., E.164 number), in analogy with SCCP GTT in SS7 networks, modeled in [ITU-T Q.714]. It may also be based on Hostname information, IP address or pointcode contained in the called party address. This allows for greater scalability, reliability and flexibility in wide-scale deployments of SUA. The usage of a relay function is a deployment decision.1.5. Internal Functions Provided in the SUA Layer
To perform its addressing and relaying capabilities, the SUA makes use of an Address Mapping Function (AMF). This function is considered part of SUA, but the way it is realized is left implementation / deployment dependent (local tables, DNS [3761], LDAP, etc.) The AMF is invoked when a message is received at the incoming interface. The AMF is responsible for resolving the address presented in the incoming SCCP/SUA message to SCTP associations to destinations within the IP network. The AMF will select the appropriate SCTP association based upon routing context / routing key information available. The destination might be the end SUA node or a SUA relay node. The Routing Keys reference an Application Server, which will have one or more ASPs processing traffic for the AS. The availability and status of the ASPs is handled by SUA ASP management messages.
Possible SS7 address/routing information that comprise a Routing Key entry includes, for example, OPC, DPC, SIO found in the MTP3 routing label, SCCP subsystem number, or Transaction ID. IP addresses and hostnames can also be used as Routing Key Information. It is expected that the routing keys be provisioned via a MIB, dynamic registration or external process, such as a database.1.5.1. Address Mapping at the SG
Normally, one or more ASPs are active in the AS (i.e., currently processing traffic) but in certain failure and transition cases it is possible that there may not be an active ASP available. The SGP will buffer the message destined for this AS for a time T(r) or until an ASP becomes available. When no ASP becomes available before expiry of T(r), the SGP will flush the buffered messages and initiate the appropriate return or refusal procedures. If there is no address mapping match for an incoming message, a default treatment MAY be specified. Possible solutions are to provide a default Application Server to direct all unallocated traffic to a (set of) default ASP(s), or to drop the messages and provide a notification to management. The treatment of unallocated traffic is implementation dependent.1.5.2. Address Mapping at the ASP
To direct messages to the SS7 network, the ASP MAY perform an address mapping to choose the proper SGP for a given message. This is accomplished by observing the Destination Point Code and other elements of the outgoing message, SS7 network status, SGP availability, and Routing Context configuration tables. A Signalling Gateway may be composed of one or more SGPs. There is, however, no SUA messaging to manage the status of an SGP. Whenever an SCTP association to an SGP exists, it is assumed to be available. Also, every SGP of one SG communicating with one ASP regarding one AS provides identical SS7 connectivity to this ASP. An ASP routes responses to the SGP that it received messages from; within the routing context which it is currently active and receiving traffic.1.5.3. Address Mapping Function at a Relay Node
The relay function is invoked when: - Routing is on Global Title
- Routing is on Hostname
- Routing is on SSN and PC or SSN and IP Address and the address
presented is not the one of the relay node
Translation/resolution of the above address information yields one of
the following:
- Route on SSN: SCTP association ID toward the destination node, SSN
and optionally Routing Context and/or IP address.
- Route on GT: SCTP association ID toward next relay node, (new) GT
and optionally SSN and/or Routing Context.
- Routing on Hostname: SCTP association ID toward next relay node,
(new) Hostname and optionally SSN and/or Routing Context.
- A local SUA-user (combined relay/end node)
To prevent looping, an SS7 hop counter is used. The originating end
node (be it an SS7 or an IP node) sets the value of the SS7 hop
counter to the maximum value (15 or less). Each time the relay
function is invoked within an intermediate (relay) node, the SS7 hop
counter is decremented. When the value reaches zero, the return or
refusal procedures are invoked with reason "Hop counter violation".
1.5.4. SCTP Stream Mapping
The SUA supports SCTP streams. Signalling Gateway SG and Application
Servers need to maintain a list of SCTP and SUA-users for mapping
purposes. SCCP-users requiring sequenced message transfer need to be
sent over a stream with sequenced delivery.
SUA uses stream 0 for SUA management messages. It is OPTIONAL that
sequenced delivery be used to preserve the order of management
message delivery.
Stream selection based on protocol class:
- Protocol class 0: SUA MAY select unordered delivery. The stream
selected is based on traffic information available to the SGP or
ASP.
- Protocol class 1: SUA MUST select ordered delivery. The stream
selected is based upon the sequence parameter given by the upper
layer over the primitive interface and other traffic information
available to the SGP or ASP
- Protocol classes 2 and 3: SUA MUST select ordered delivery. The
stream selected is based upon the source local reference of the
connection and other traffic information available to the SGP or
ASP.
1.5.5. Flow Control
Local Management at an ASP may wish to stop traffic across an SCTP association to temporarily remove the association from service or to perform testing and maintenance activity. The function could optionally be used to control the start of traffic on to a newly available SCTP association.1.5.6. Congestion Management
The SUA layer is informed of local and IP network congestion by means of an implementation-dependent function (e.g., an implementation- dependent indication from the SCTP of IP network congestion). At an ASP or IPSP, the SUA layer indicates congestion to local SCCP- Users by means of an appropriate SCCP primitive (e.g., N-INFORM, N- NOTICE), as per current SCCP procedures, to invoke appropriate upper layer responses. When an SG determines that the transport of SS7 messages is encountering congestion, the SG MAY trigger SS7 SCCP Congestion messages to originating SS7 nodes, per the congestion procedures of the relevant SCCP standard. The triggering of SS7 SCCP Management messages from an SG is an implementation-dependent function. The SUA layer at an ASP or IPSP MAY indicate local congestion to an SUA peer with an SCON message. When an SG receives a congestion message (SCON) from an ASP, and the SG determines that an endpoint is now encountering congestion, it MAY trigger congestion procedures of the relevant SCCP standard.1.6. Definition of SUA Boundaries
1.6.1. Definition of the upper boundary
The following primitives are supported between the SUA and an SCCP- user (a reference to ITU and ANSI sections where these primitives and corresponding parameters are described, is also given): Generic |Specific | Name |Name |ANSI/ITU Reference ------------+----------+------------------------------------------- N-CONNECT |Request |ITU-Q.711 Chap 6.1.1.2.2 (Tab 2/Q.711) |Indication|ANSI-T1.112 Chap 2.1.1.2.2 (Tab 2/T1.112.1) |Response | |Confirm | ------------+----------+------------------------------------------- N-DATA |Request |ITU-Q.711 Chap 6.1.1.2.3 (Tab 3/Q.711) |Indication|ANSI-T1.112 Chap 2.1.1.2.3 (Tab 3/T1.112.1)
------------+----------+-------------------------------------------
N-EXPEDITED |Request |ITU-Q.711 Chap 6.1.1.2.3 (Tab 4/Q.711)
DATA |Indication|ANSI-T1.112 Chap 2.1.1.2.3 (Tab 4/T1.112.1)
------------+----------+-------------------------------------------
N-RESET |Request |ITU-Q.711 Chap 6.1.1.2.3 (Tab 5/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.3 (Tab 5/T1.112.1)
|Response |
|Confirm |
------------+----------+-------------------------------------------
N-DISCONNECT|Request |ITU-Q.711 Chap 6.1.1.2.4 (Tab 6/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.4 (Tab 6/T1.112.1)
------------+----------+-------------------------------------------
N-INFORM |Request |ITU-Q.711 Chap 6.1.1.3.2 (Tab 8/Q.711)
|Indication|ANSI-T1.112 Chap 2.1.1.2.5 (Tab 6A/T1.112.1)
------------+----------+-------------------------------------------
N-UNITDATA |Request |ITU-Q.711 Chap 6.2.2.3.1 (Tab 12/Q.711)
|Indication|ANSI-T1.112 Chap 2.2.2.3.1 (Tab 8A/T1.112.1)
------------+----------+-------------------------------------------
N-NOTICE |Indication|ITU-Q.711 Chap 6.2.2.3.2 (Tab 13/Q.711)
| |ANSI-T1.112 Chap 2.2.2.3.2 (Tab 8B/T1.112.1)
------------+----------+--------------------------------------------
N-STATE |Request |ITU-Q.711 Chap 6.3.2.3.2 (Tab 16/Q.711)
|Indication|ANSI-T1.112 Chap 2.3.2.3.2 (Tab 8E/T1.112.1)
------------+----------+--------------------------------------------
N-PCSTATE |Indication|ITU-Q.711 Chap 6.3.2.3.3 (Tab 17/Q.711)
| |ANSI-T1.112 Chap 2.3.2.3.4 (Tab 8G/T1.112.1)
------------+----------+--------------------------------------------
N-COORD |Request |ITU-Q.711 Chap 6.3.2.3.1 (Tab 15/Q.711)
|Indication|ANSI-T1.112 Chap 2.3.2.3.3 (Tab 8F/T1.112.1)
|Response |
|Confirm |
1.6.2. Definition of the lower boundary
The upper layer primitives provided by the SCTP are provided in
[SCTP].
1.6.3. Definition of the Boundary between SUA and Layer Management
M-SCTP_ESTABLISH request
Direction: LM -> SUA
Purpose: LM requests ASP to establish an SCTP association with its
peer.
M-SCTP_ESTABLISH confirm
Direction: SUA -> LM
Purpose: ASP confirms to LM that it has established an SCTP
association with its peer.
M-SCTP_ESTABLISH indication
Direction: SUA -> LM
Purpose: SUA informs LM that a remote ASP has established an SCTP
association.
M-SCTP_RELEASE request
Direction: LM -> SUA
Purpose: LM requests ASP to release an SCTP association with its
peer.
M-SCTP_RELEASE confirm
Direction: SUA -> LM
Purpose: ASP confirms to LM that it has released SCTP association
with its peer.
M-SCTP_RELEASE indication
Direction: SUA -> LM
Purpose: SUA informs LM that a remote ASP has released an SCTP
Association or the SCTP association has failed.
M-SCTP RESTART indication
Direction: SUA -> LM
Purpose: SUA informs LM that an SCTP restart indication has been
received.
M-SCTP_STATUS request
Direction: LM -> SUA
Purpose: LM requests SUA to report the status of an SCTP
association.
M-SCTP_STATUS confirm
Direction: SUA -> LM
Purpose: SUA responds with the status of an SCTP association.
M-SCTP STATUS indication
Direction: SUA -> LM
Purpose: SUA reports the status of an SCTP association.
M-ASP_STATUS request
Direction: LM -> SUA
Purpose: LM requests SUA to report the status of a local or remote
ASP.
M-ASP_STATUS confirm
Direction: SUA -> LM
Purpose: SUA reports status of local or remote ASP.
M-AS_STATUS request
Direction: LM -> SUA
Purpose: LM requests SUA to report the status of an AS.
M-AS_STATUS confirm
Direction: SUA -> LM
Purpose: SUA reports the status of an AS.
M-NOTIFY indication
Direction: SUA -> LM
Purpose: SUA reports that it has received a Notify message from its
peer.
M-ERROR indication
Direction: SUA -> LM
Purpose: SUA reports that it has received an Error message from its
peer or that a local operation has been unsuccessful.
M-ASP_UP request
Direction: LM -> SUA
Purpose: LM requests ASP to start its operation and send an ASP Up
message to its peer.
M-ASP_UP confirm
Direction: SUA -> LM
Purpose: ASP reports that is has received an ASP UP Ack message
from its peer.
M-ASP_UP indication
Direction: SUA -> LM
Purpose: SUA reports it has successfully processed an incoming ASP
Up message from its peer.
M-ASP_DOWN request
Direction: LM -> SUA
Purpose: LM requests ASP to stop its operation and send an ASP Down
message to its peer.
M-ASP_DOWN confirm
Direction: SUA -> LM
Purpose: ASP reports that is has received an ASP Down Ack message
from its peer.
M-ASP_DOWN indication
Direction: SUA -> LM
Purpose: SUA reports it has successfully processed an incoming ASP
Down message from its peer, or the SCTP association has
been lost/reset.
M-ASP_ACTIVE request
Direction: LM -> SUA
Purpose: LM requests ASP to send an ASP Active message to its peer.
M-ASP_ACTIVE confirm
Direction: SUA -> LM
Purpose: ASP reports that is has received an ASP Active Ack message
from its peer.
M-ASP_ACTIVE indication
Direction: SUA -> LM
Purpose: SUA reports it has successfully processed an incoming ASP
Active message from its peer.
M-ASP_INACTIVE request
Direction: LM -> SUA
Purpose: LM requests ASP to send an ASP Inactive message to its
peer.
M-ASP_INACTIVE confirm
Direction: LM -> SUA
Purpose: ASP reports that is has received an ASP Inactive
Ack message from its peer.
M-ASP_INACTIVE indication
Direction: SUA -> LM
Purpose: SUA reports it has successfully processed an incoming ASP
Inactive message from its peer.
M-AS_ACTIVE indication
Direction: SUA -> LM
Purpose: SUA reports that an AS has moved to the AS-ACTIVE state.
M-AS_INACTIVE indication
Direction: SUA -> LM
Purpose: SUA reports that an AS has moved to the AS-INACTIVE state.
M-AS_DOWN indication
Direction: SUA -> LM
Purpose: SUA reports that an AS has moved to the AS-DOWN state.
If the SUA layer supports dynamic registration of Routing Key, the
layer MAY support the following additional primitives:
M-RK_REG request
Direction: LM -> SUA
Purpose: LM requests ASP to register RK(s) with its peer by sending
REG REQ message.
M-RK_REG confirm
Direction: SUA -> LM
Purpose: ASP reports that it has received REG RSP message with
registration status as successful from its peer.
M-RK_REG indication
Direction: SUA -> LM
Purpose: SUA informs LM that it has successfully processed an
incoming REG REQ message.
M-RK_DEREG request
Direction: LM -> SUA
Purpose: LM requests ASP to deregister RK(s) with its peer by
sending DEREG REQ message.
M-RK_DEREG confirm
Direction: SUA -> LM
Purpose: ASP reports that it has received DEREG RESP message with
deregistration status as successful from its peer.
M-RK_DEREG indication
Direction: SUA -> LM
Purpose: SUA informs LM that it has successfully processed an
incoming DEREG REQ from its peer.
2. Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in
BCP 14, RFC 2119 [2119].
(page 19 continued on part 2)