Contents

1   Introduction

This document describes how to configure the MTAS Number Translation service in the MTAS.

1.1   Prerequisites

It is assumed that the user of this document is familiar with the O&M area, in general.

1.1.1   Licenses

To enable the MTAS Number Translation service, the MMTel license must be installed.

For more information about the MMTel license, refer to MTAS Licenses.

1.1.2   Documents

Before starting any of the procedures in this document, the following documents must be available:

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

1.1.3   Conditions

The following condition must apply:

• An Ericsson Command-Line Interface (ECLI) session in Exec mode is in progress.

2   Overview

The Number Translation function translates dialed local or global numbers based on translation rules configured by the operator.

With the Number Translation service, a substitution rule-set using regular expressions can be applied to the number part of a tel URI or a number-based SIP URI (that is, embedded tel URI) received in the following:

• Request-URI of SIP INVITE
• Refer-To header of SIP REFER

Number Translation is active when its administrative state is unlocked on originating side and on terminating side in transit mode.

For more information about the URIs, refer to the following standards:

• IETF RFC 3261, SIP: Session Initiation Protocol
• IETF RFC 3966: The tel URI for Telephone Numbers

2.1   Subfunctions

The subfunctions included in the Number Translation service are described in this section.

2.1.1   Configure the Number Translation Rules

The translation rules are configured and activated by the operator, see Section 3 Number Translation Configuration and Section 4 Configuration Examples for more information.

2.1.2   Translate Number

The translation rules are applied to numbers dialed by the originating end user.

2.2   Interaction with Other Services

Number translation is executed after using the Abbreviated Dialing function and handling of Supplementary Service Codes but before Dial Number Mapping, Number Normalization, Short Number Dialing, and Hotline Service. Before selecting and applying the translation rules, the visual separators and the Carrier Select Codes are removed from the input number and user-equals-phone error correction is executed.

2.2.1   Abbreviated Dialing

For more information about the Abbreviated Dialing service of the MTAS, refer to MTAS Abbreviated Dialing Management Guide.

2.2.2   Carrier Select and Carrier Pre-Select

For more information about the Carrier Select and Carrier Pre-Select services of the MTAS, refer to MTAS Carrier Select and Carrier Pre-Select Management Guide.

2.2.3   Dialed Number Mapping

The Number Translation service can be used as part of the Dialed Number Mapping function to help location-dependent number analysis and replacement.

For more information about the Dialed Number Mapping service of the MTAS, refer to MTAS Dialed Number Mapping Management Guide.

2.2.4   Hotline Service

For more information about the Hotline service of the MTAS, refer to MTAS Hotline Service Management Guide.

2.2.5   Number Normalization

For more information about the Number Normalization service of the MTAS, refer to MTAS Number Normalization Management Guide.

2.2.6   Short Number Dialing

For more information about the Short Number Dialing service of the MTAS, refer to MTAS Short Number Dialing Management Guide.

2.2.7   STOD Call Pull

STOD Call Pull is not allowed for call sessions targeted at service numbers configured in the network of the operater, which includes National short codes.

National short codes must match a Number Translation rule which includes the "$NSC" token, to be recognized by MMTel AS.

For more information about the STOD Call Pull service of the MTAS, refer to MTAS Session Transfer to Own Device Management Guide.

2.2.8   Supplementary Service Codes

For more information about the Supplementary Service Codes service of the MTAS, refer to MTAS Supplementary Service Codes Management Guide.

3   Number Translation Configuration

The Number Translation service rules are configured through the O&M interface and controlled by the mtasNumberTranslation MO. An overview of the Number Translation MO structure is shown in Figure 1.

Configurable MOs and attributes related to the Number Translation service are defined in Managed Object Model (MOM).

3.1   Number Translation Administrative State Configuration

The Number Translation service is enabled by setting the mtasNumberTranslationAdministrativeState attribute in the mtasNumberTranslation MO to 1 (Unlocked). If the mtasNumberTranslationAdministrativeState is set to 0 (Locked), no Number Translation service is provided by the MTAS.

3.2   Wholesale for Number Translation Configuration

The Number Translation service supports Wholesale. The Number Translation is configurable on Virtual Telephony Provider (VTP)-level.

Wholesale for the Number Translation is activated when the following attributes are set to 1 (Unlocked):

• The vtasNumberTranslationAdministrativeState attribute in the VtasNumberTranslation MO
• The mtasNumberTranslationAdministrativeState attribute in the MtasNumberTranslation MO

For more information about the Wholesale service, refer to MTAS Wholesale Support Management Guide.

3.3   Configuration Activities

The configuration activities are listed in Table 1.

3.4   Number Translation Profile Configuration

The profile applicable to an input number is selected based on the key of the MtasNumberTranslationProfile. The substitution rules are stored in the different entries of the mtasNumberTranslationRule.

3.5   Translation Rules

The translation rules can be organized in up to a 1000 profiles including a default profile. The number prefix used as a profile name must be unique and shorter than 16 characters. The profile name can contain digits 0–9 and the characters "s", "h", and "p". Alternatively, the profile name can have the value DEFAULT defining the default profile.

The characters "s", "h", and "p"are replacements for "*", "#", and "+" which have a special meaning in LDAP Distinguished Names and thus they cannot be used to configure a Number Translation profile over the MTAS OAM interface. The Number Translation function resolves the character replacements before building the Number Translation lookup tree. Replacement only applies to profile names, these characters must not be replaced in substitution rules.

A lookup tree for selecting the applicable translation rule based on the prefix of the input number is shown in Figure 2. MTAS builds a lookup tree to select the applicable profile efficiently. The lookup tree is built on startup and is rebuilt whenever new translation rules are activated, see Section 3.6 Activation Mechanism for details on the activation mechanism.

To find and execute the applicable translation rule, do the following:

1. The profile with the longest matching prefix is selected using the lookup tree. The lookup is performed in several steps equal with the length of the longest matching prefix. If no profile matching the prefix of the input number is found, the default profile is used. If there is no default profile, the input number is returned.
2. If there are no matching rules in the selected profile, the input number is returned. Otherwise, the first matching rule is executed. If the rule is terminal, the result is returned. Otherwise, the next matching rule is executed until there are no more rules in the profile.

Before executing the translation rules, the visual separators are removed from the input number.

The configured translation rules have the following format (similar to the Number Normalization rules):

Order:Substitution-rule:Terminal-match:Description

The different parts of the translation rule have the following explanation:

• Order

  An unsigned integer that defines which rule that is being matched first. The lowest number has the highest priority.

• Substitution-rule

  A POSIX 1003.2 extended regular substitution rule of format /regexp/replacement/. Characters "*", "#" and "+" are allowed in this field and no replacement are to be used for them.

  Note:  

  Characters "*" and "+" are to be escaped in regular expressions.

  
  
• Terminal-match

  The value is either "TRUE" or "FALSE" indicating if the expression is terminal or not. If there is a terminal expression, the substitution result is returned, otherwise, further substitutions are performed.

• Description

  Description is an optional field. It can be used to some explanatory text for the rule. The characters "/ " and ":" are not allowed in this field.

For configuration examples, see Section 4 Configuration Examples.

The substitution rules configured for the Number Translation service must not conflict with the Number Normalization rules and are set up by considering the configured OSN/NSN numbers, Carrier Select special numbers, test numbers, Global White/Black List, and also Barring Categories where there is partial match for leftmost digits.

3.6   Activation Mechanism

The mtasNumberTranslationActivationState attribute controls the mechanism used to load and cache the translation rules. By default it is set to 0 (Idle). Updating the cached data is started when it is set by the operator to 1 (Activate). When the data is fully loaded, the activation state is set back to 0 (Idle) automatically.

4   Configuration Examples

This section presents configuration examples for the Number Translation function.

The Number Translation configuration with rule-set 1 is shown in Example 1.

MtasNumberTranslationProfile: 
MtasNumberTranslationRule: 10:/^123$/7654321/:TRUE
mtasNumberTranslationRule: 20:/^456$/4321765/:TRUE

The rule-set 1 configuration in Example 1 has the following input and output URIs:

• Input URI

  tel:456

• Output URI

  tel:4321765

The Number Translation configuration with rule-set 2 is shown in Example 2.

MtasNumberTranslationProfile: "45"
mtasNumberTranslationRule: "10:/^455//:TRUE"
mtasNumberTranslationRule: "20:/789$//:TRUE"

MtasNumberTranslationProfile: "459"
mtasNumberTranslationRule: "10:/^459//:FALSE"
mtasNumberTranslationRule: "20:/789$//:FALSE"
mtasNumberTranslationRule: "30:/^4556$/2847/:TRUE"

MtasNumberTranslationProfile: "s22"
mtasNumberTranslationRule: "10:/^\*22$/770261143/:TRUE: \
Whoesale customer"

MtasNumberTranslationProfile: "DEFAULT"
mtasNumberTranslationRule: "10:/1234/5555/:TRUE"

Note:  

The "*" character in translation profile s22 must be escaped in the regular expression.

The rule-set 2 configuration in Example 2 has input and output URIs as in Table 2:

The Number Translation configuration with rule-set 3 is shown in Example 3.

MtasNumberTranslationProfile="310"

mtasNumberTranslationRule="1:/(^310[0-9]{4})/$LOC\1&PRE/TRUE"
MtasNumberTranslationProfile: "DEFAULT"
mtasNumberTranslationRule: "10:/^1234/\1|$PCM/:TRUE"

The rule-set 3 configuration in Example 3 has input and output URIs as described in Table 3.

Profile = 310

Profile = DEFAULT

For the first URI, the Number Translation Service matched a toll-free number starting with the digits 310; inserts "$LOC" before the dialed digits and "&PRE" after the dialed digits. The "$LOC" string is replaced by the Dialed Number Mapping service to a location-specific string. The "PRE" string serves as an input also to the Dialed Number Mapping service.

For second URI, the Number Translation service matched a number starting with the digits 1234; inserts "|$PCM" after the dialed digits. The "$PCM" string is indicator for the Dialed Number Mapping service to modify the phone-context of the dialed number.

For more information about the Dialed Number Mapping service of the MTAS, refer to MTAS Dialed Number Mapping Management Guide.

5   Performance Management

Measurements related to the Number Translation service are detailed in Managed Object Model (MOM).

6   Fault Management

Alarms related to the Number Translation service are listed in MTAS Alarm List.