M3UA layer

The M3UA layer enables MTP 3-like functionality to be performed over IP. It performs these primary tasks:

Task

Description

Interface to the higher and lower SS7 layers

Provides an interface between the higher SS7 layers (ISUP, SCCP, and TUP), and the lower SCTP layer. This interface is implemented with a set of messages that the application can pass to the M3UA layer on the TX communications processor.

For more information, see M3UA service function summary.

Routing

Routes messages to their IP destinations. M3UA uses a flexible configuration capable of supporting a wide variety of network routing and addressing requirements.

For more information, see M3UA message handling.

Signaling network management

Maintains the availability status of all destinations through all routes. Automatically reroutes traffic in the case of failure or congestion.


In addition to general parameters, the M3UA layer consists of the following entities:

Network definitions

A network definition is a logical network that describes the signaling traffic between two IP signaling points (IPSPs) or an application server process (ASP) and a signaling gateway (SG) over a common SCTP association. Typically only one network definition is required, unless the local node supports both ANSI and ITU networks.

The M3UA management API lets you perform the following actions on a network definition:

For more information, see M3UA management function summary.

NSAPs

Network service access points (NSAPs) define the upper layer SS7 applications that use M3UA. Each NSAP is associated with a service indicator field and protocol variant combination.

If multiple protocol variants (network definitions) or multiple upper layers must be supported on the same M3UA instance (same board), an NSAP is required for each SIO value and protocol variant. A single application can associate itself with multiple NSAPs, or a separate application can bind to each NSAP.

The M3UA management API lets you perform the following actions on an NSAP:

For more information, see M3UA management function summary.

SCT SAP

An SCT service access point (SCT SAP) defines the interface between M3UA and SCTP. It is the lower SAP for M3UA and the upper SAP for SCTP. Only one SCT SAP is defined.

The following illustration shows three NSAPS and one SCT SAP defined for an M3UA layer:

The M3UA management API lets you perform the following actions on the SCT SAP:

For more information, see M3UA management function summary.

Peer servers

A peer server (PS) is a logical entity on the IP network, such as a virtual switch or a database element, that is served by one or more peer signaling processes (PSPs). Each peer server serves a specific routing key. For example, a peer server can handle a signaling relation identified by a DPC/OPC combination or an SIO/DPC/OPC combination. There is a one-to-one relationship between a peer server and a routing key. Peer servers can be local or remote.

The M3UA API lets you perform the following actions on a peer server:

For more information, see M3UA management function summary.

Peer signaling processes

A peer signaling process (PSP) is used to describe a remote SGP or IPSP that is, or will be, accessible from the local M3UA through an association. It is an executing process that handles signaling traffic for one or more peer servers/routing keys. A peer signaling process can be in an active or standby state.

The M3UA API lets you perform the following actions on a peer signaling process:

Note: The local M3UA is a special case and is referred to as the local PSP. This local PSP is created automatically, not configured.

For more information, see M3UA management function summary.

SCTP associations

An SCTP association is a logical relationship between two SCTP endpoints that is used to transport M3UA user protocol messages between two peer servers. The transport addresses used by the endpoints in the association uniquely identify that association. Two SCTP endpoints cannot have more than one SCTP association between them at any given time. Each M3UA instance can support up to 254 associations.

The Dialogic® NaturalAccess™ M3UA API lets you perform the following actions on an association:

For more information, see M3UA management function summary.

Routing keys

A routing key defines the range of signaling traffic to be handled by a particular peer server. Routing keys are defined using combinations of the following parameters:

The M3UA API lets you perform the following actions on a routing key:

For more information, see M3UA management function summary.