Contents

1   Introduction

This document describes how to configure the Network Application Server (NW AS) in the MTAS. The NW AS node in the IP Multimedia Subsystem (IMS) provides the interworking SIP signaling between the entities lacking specific capabilities. Current version of NW AS supports function(PrIwf) and Forking Interworking Function (FoIwf). PrIwf supports Quality of Service (QoS) precondition SIP signaling interworking for terminating endpoints, which lack precondition support. FoIwf provides interworking between a caller endpoint lacking support of multiple early dialogs and the IMS network.

1.1   Prerequisites

It is assumed that the user of this document is familiar with the Operation and Maintenance (O&M) area, in general.

1.1.1   Licenses

To enable the functionality in the NW AS, the Communication IWF AS Base license must be installed.

To enable the FoIwf, the Forking Interworking Function license must be installed.

For more information about the Communication IWF AS Base license and Forking Interworking Function license, refer to MTAS Licenses.

1.1.2   Documents

Before starting any procedure in this document, ensure that the following documents are available:

• Managed Object Model (MOM)
• Ericsson Command-Line Interface User Guide

1.1.3   Conditions

Before starting any of the procedures in this document, ensure that an Ericsson Command-Line Interface (ECLI) session in Exec mode is in progress.

2   Overview

The NW AS is an interworking node in the IMS to provide communication interworking SIP signaling between entities that are missing some capabilities. The NW AS acts as a Back-to-Back User Agent (B2BUA) between these entities. Current version supports PrIwf and FoIwf.

PrIwf function provides SIP signaling interworking for terminating UEs that do not support QoS preconditions.

FoIwf supports aggregation of multiple early dialogues to a single dialogue. This Interworking Function is applicable when calling party side lacks support of multiple early dialogues. The NWAS can be deployed either as a standalone node or as collocated.

3   NW AS Configuration

The Communication IWF functionality in the NW AS is controlled by the MtasNw Managed Object (MO).

The NW AS MO structure is shown in Figure 1.

For MOs and attributes related to the NW AS, refer to Managed Object Model (MOM).

3.1   NW AS Administrative State Configuration

The NW AS is enabled by setting the mtasNwAdministrativeState attribute in the MtasNw MO to 1 (Unlocked). If the mtasNwAdministrativeState is set to 0 (Locked), the NW AS function is not provided by the MTAS.

3.2   NW AS Name Configuration

The NW AS name is configured by setting the mtasFunctionNwPrIwAsName attribute or mtasFunctionNwFoIwAsName in the MtasFunction MO to define the name of the AS variant in network AS. This configured name is matched with received "as" parameter value in top most route header from the Call Session Control Function (CSCF).

3.3   NW SIP Port Configuration

It is possible to change the SIP port used for SIP Communication IWF traffic in the NW AS.

For configuration of the NW AS SIP port, refer to MTAS SIP Management Guide.