5.1 Introduction

5.2 MTP 3 Configuration

5.3 MTP 3 Status Requests

5.4 MTP 3 Control Requests

5.5 MTP 3 Statistics Requests

5.1 Introduction

The MTP 3 management API facilitates the development of applications which can configure, monitor, and/or control the operation of the SS7 MTP 3 layer.

All management primitives are synchronous, meaning the action is completed before control is returned to the application. Thus, the application obtains the final result of the action and can act upon it immediately. There are no asynchronous indications in the management API.

The following subsections provide an overview of the management primitives available to application developers.

5.2 MTP 3 Configuration

The MTP 3 layer configuration is comprised of the following entities:

• General configuration parameters

• Network Service Access Points, or NSAPs

• Signaling Links

• Signaling Linksets

• Signaling Routes

The relationship between these entities is shown in Figure 12.

Figure 12. MTP 3 Configurable Entities

The general configuration parameters define and control the general operation of the signaling point (SP) implemented by the SS7 software. General configuration parameters include the type of signaling point being constructed (SP or STP), the point code assigned to the signaling point, the values for various SP-level timers, and the maximum number of other configurable elements (user parts (NSAPs), links, linksets, routes) to control memory allocation. The general parameters are configured once at board download time, before any other entities are configured. After the general configuration is performed the first time, only the "restart required" attribute, timers, and routing masks may be reconfigured (other parameters are ignored on subsequent general configuration requests). The board must be downloaded again to change any of the other general configuration parameters.

Network service access points (NSAPs) define the SS7 user parts, or applications, that are users of the MTP service. The configurable attributes of NSAPs include the protocol variant (ITU-T or ANSI) and point code length supported by the user part/application associated with the NSAP, and the maximum number of user part/application messages to be queued (at each of the four possible message priority levels) when flow control between the MTP 3 and application is in effect. NSAPs may be defined at any time after the general configuration parameters are defined (up to the maximum number of NSAPs allowed by the general configuration parameters definition). Once an NSAP is defined, all of its parameters may be changed by calling the NSAP configuration function again.

Links define physical signaling links between the TX board and the adjacent signaling points. The configurable attributes of a link include the point code of the adjacent signaling point, protocol variant employed on the link (ITU-T or ANSI), point code length, maximum packet length, various timer values, membership in a linkset, and others. Links may be defined at any time after the general configuration parameters (up to the maximum number of links allowed by the general configuration parameters definition). Once a link is defined, many of its attributes may be changed by calling the link configuration request again (see Mtp3InitLinkCfg for a list of attributes that may be changed). Links may also be deleted with the remove link control request.

Linksets are groups of from one to 16 links that directly connect two signaling points. The configurable attributes of a linkset include the point code of the adjacent signaling point, whether or not to load share traffic across all links in the linkset, and the number of links to attempt to keep active. Linksets may be defined at any time after the general configuration parameters (up to the maximum number of linksets allowed by the general configuration parameters definition). Once a linkset is defined, the target number of active links and the defined combined linksets may be changed by calling the linkset configuration request again. The board must be downloaded again to change any of the other linkset configuration parameters.

Routes specify the destination signaling points (or subnetworks - e.g., clusters - when route masks are employed) that are accessible from the node being configured. Each route is assigned a direction - up or down. Up routes are used to identify incoming messages that are to be routed up to the applications/user parts. One down route is required for each remote signaling point/network/cluster that is to be accessible from the SP being configured. Down routes are used to route outgoing messages to the appropriate signaling links.

Other configurable attributes of routes include the destination point code, the protocol variant in use at the destination SP/cluster/network, and others. Routes may be defined at any time after the general configuration parameters (up to the maximum number of routes allowed by the general configuration parameters definition). Once a route is defined, some of its attributes may be changed by calling the route configuration request again (see Mtp3InitRouteCfg for a list of attributes that may be changed).

5.3 MTP 3 Status Requests

The MTP 3 management API allows the application to retrieve the current status of the following entities:

Entity	Status Returned
Signaling Point	Restart in progress or not High Availability State (primary | backup | stand alone)
NSAP	State (bound | unbound) Flow Control Status (on | off) Congestion Discard Count
Link	Current State (active | inactive) Remotely Blocked (yes | no) Locally Blocked (yes | no) Remotely Inhibited (yes | no) Locally Inhibited (yes | no) Congested (yes | no) Emergency State (yes | no)
Linkset	Current State (active | inactive) Congested (yes | no) Number of active links Number of congested links
Route	Current State (accessible | inaccessible) Congested (yes | no) Number of active linksets Number of congested linksets Destination restart in progress (yes | no)

5.4 MTP 3 Control Requests

The MTP 3 management API allows the application to control aspects of the following entities:

Entity	Control Request Type
Signaling Point	Enable | Disable Alarms Enable | Disable Flow Control Enable | Disable Data Tracing
Link	Enable | Disable Link Inhibit | Uninhibit Link Delete a Link Start | End Local Processor Outage Start | End Emergency Condition Enable | Disable Data Tracing
Linkset	Activate | Deactivate Linkset

5.5 MTP 3 Statistics Requests

The MTP 3 management API allows the application to retrieve, and optionally reset, statistics on the signaling point in general, links, linksets, and routes. See the individual primitive reference for a list of the statistics reported for each of these entities.