CUDB Technical Product Description
CUDB 1

Contents

1Introduction
1.1Purpose and Scope
1.2Revision Information
1.3Target Groups
1.4Prerequisites
1.5Typographic Conventions

2
Overview
2.1Supported Hardware

3
Functions
3.1General
3.2CUDB Functionality
3.3Security

4
Interfaces
4.1Reference Model
4.2Protocols

5
Architecture
5.1Logical Components

6
OAM
6.1Fault Management
6.2Performance Management
6.3Log Management
6.4Configuration and Software Management

7
Configuration
7.1CUDB Node Configuration
7.2CUDB System Configuration

8
Characteristics
8.1Availability and Reliability
8.2Scalability

Glossary

Reference List

1   Introduction

This document provides an overview of the Ericsson Centralized User Database (CUDB).

CUDB is an extensible, high-performance, subscriber-centric database system, able to consolidate subscriber data for several application Front Ends (FEs). This telecom-grade, real-time, geographically distributed database system can store both static and dynamic data, as well as subscriber-related service data.

CUDB provides controlled and enhanced access to subscriptions and allows seamless traffic business growth by offering a single point of provisioning, as well as effortless introduction of new services in a network through simplified subscriber and service management with significant cost savings.

Note:  
This document applies to the node main release and all its consecutive software drops. The delivery dates of specific functions may diverge. For specific details on General Availability dates, check UDM Roadmap.

1.1   Purpose and Scope

This document describes the architecture, functions, interfaces, element management, subscriber data management, and characteristics of CUDB.

1.2   Revision Information


Rev. A
Rev. B
Rev. C
Rev. D
Rev. E
Rev. F
Rev. G
Rev. H
Rev. J
Rev. K

Other than editorial changes, this document has been revised as follows:

1.3   Target Groups

This document is intended as an introduction to CUDB for network operators, network and service planners, as well as system engineers and administrators.

1.4   Prerequisites

Users of this document must have a basic knowledge of data communication and telecommunication.

1.5   Typographic Conventions

Typographic conventions can be found in the following document:

2   Overview

Ericsson evolved its telecommunications subscriber database used by its mobile circuit switch and packet switch networks, its IP Multimedia System (IMS), and Evolved Packet Core (EPC) solutions. The result of the development is the Ericsson User Data Consolidation (UDC), a system based on a layered architecture and the physical or logical decoupling of subscriber data, application service, and business logic into different network elements.

The network elements are as follows:

Figure 1   UDC

All subscriber-related data is stored and managed in the CUDB data layer, while service logic that was previously triggered and executed in the classic HLR monolithic architecture is now performed on the HLR-FE node. Similarly, the service logic provided by the classic Home Subscriber Server (HSS) / Subscription Locator Function (SLF) Monolithic Architecture is executed on the HSS/SLF FE node, while the subscriber data is stored in CUDB. The same strategy is applied to other application FEs.

CUDB is a distributed system of connected CUDB nodes that cooperate to provide seamless database service. A CUDB node is the main architectural unit of this network, comprising both hardware and software components. It is a physical cabinet or a Virtualized Network Function (VNF) that provides access to CUDB system services. CUDB nodes can be placed in different network locations for distribution and redundancy purposes.

Figure 2   Ericsson UDC Overview

CUDB stores subscriber profiles and provisioned (static) or non-provisioned (dynamic) service data associated to subscribers. As a subscriber-centric database, CUDB also holds the service profiles for the supported applications.

CUDB supports application FEs, such as HLR and HSS/SLF. Other application FEs can be supported through integration services.

2.1   Supported Hardware

CUDB supports the Ericsson Blade Server Platform (BSP) 8100 hardware platform with Generic Ericsson Processor version 5 (GEP5) blades or Generic Ericsson Processor version 3 (GEP3) blades.

CUDB supports virtualized environments. CUDB is verified to run on the Ericsson Cloud Execution Environment (CEE), on BSP 8100 hardware with GEP5 blades. Support for other virtualized environments or hardware is possible, but must be secured through an integration project.

It is possible to combine nodes with different hardware platforms in the same CUDB system. Mixing the following platform combinations in hybrid systems is allowed:

Note:  
Combining GEP3 and GEP5 blades in the same node is not supported.

3   Functions

This section provides details on CUDB functions.

3.1   General

CUDB is a highly available, geographically redundant, real-time, distributed database exposed as a Lightweight Directory Access Protocol (LDAP) directory to HLR, Authentication Center (AuC), HSS/SLF, or any other applications.

3.2   CUDB Functionality

CUDB is a geographically distributed system that provides local single logical points of access for traffic and provisioning. Each CUDB node provides access to the entire subscription database, regardless of data distribution across the interconnected CUDB nodes. This is called a single logical point of access, physically implemented as an IP address and port pair, for each CUDB node. The internal CUDB network and node architecture are transparent to applications.

When subscriber data is being provisioned, CUDB automatically balances the amount of stored data among the available data partitions, although custom data distribution policies may also be defined. In both cases, CUDB makes it possible to store data on particular subscribers in CUDB nodes located in specific geographical areas.

3.2.1   Structured, Flexible and Extensible Common Data Model

CUDB stores subscription information using an LDAP Directory Information Tree (DIT) as the application data model. The LDAP tree is divided into different parts, managed and handled in different database clusters or cluster groups, becoming a distributed LDAP directory. For further details on LDAP, refer to CUDB LDAP Interwork Description, Reference [1].

Subscriber data for multiple applications or network elements is supported simultaneously.

CUDB supports the Ericsson 2G/3G (HLR-FE), 4G, 5G and IMS (HSS-FE), AuC, Service-Aware Policy Controller (SAPC), Machine-to-Machine (M2M), AAA, Mobile Number Portability (MNP), E.164 Number Mapping (ENUM), Equipment Identity Register (EIR), and Internet of Things (IoT) profiles.

The structured data model is flexible and extensible. Extensibility is achieved through configuration. Data model extension is carried out online without system degradation. New types of subscriber application profiles, application common data profiles, and subscriber common data profiles can be created, and as such, new services can be introduced with a shorter time to market and without impacting traffic.

CUDB supports multiple identifiers per subscriber. New types of identifiers can also be added dynamically without system degradation.

3.2.2   Data Distribution

The subscriber data set is divided into disjoint subsets. Each of these subsets is stored on a data partition, or Data Store Unit Group (DSG). A DSG is a subscriber data partition, the basic distribution unit of subscriber data. CUDB stores every information related to each subscriber in one DSG only, but data related to different subscribers can be allocated to different DSGs.

Each CUDB node hosts a number of database clusters. These database clusters are replicated and geographically distributed across different network sites, making up a distributed Data Store (DS) Layer. These database clusters are called DS units.

A DS unit can be configured to host data for any DSG. For example, in Figure 3, DS2 hosts data for DSG2 in CUDB node 1, but the same DSG2 is hosted by DS1 in CUDB node 5. Not all DSGs must be hosted in all CUDB nodes. However, the data stored on any DSG is accessible from any CUDB node in the system.

Figure 3   Subscriber Data Distribution

One of the DS units of the DSG is called the DS Master replica. All high-priority read and all write operations related to the subscriber data in that partition are executed in the master replica. This mechanism maintains data consistency in the CUDB system.

Modifications are replicated asynchronously to the rest of the DS units in the partition. The other DS units are in charge of low priority tasks such as massive queries, or export operations. If the DS Master replica in a DSG fails for any reason, another DS unit in that partition is appointed as the new master replica.

The Processing Layer Database (PLDB) contains the rest of the data, as aliases, profiles, and so on. PLDB also stores information on which DSG hosts data for each subscriber.

By default, subscribers are automatically distributed among the DSGs assigned to them, based on DSG occupancy. However, specifying the DSG or geographical zone where the data must be stored is also possible.

CUDB supports custom DSG distribution algorithms during provisioning. This is performed by configuring and loading the desired algorithm rules in a dynamic library.

For further information on data distribution, refer to CUDB LDAP Data Access, Reference [2].

3.2.3   Data Backup and Restore

A backup of the whole system can be ordered and executed without stopping traffic. The backup is carried out over each subscriber subset, including the contents of the entire database. During backup, traffic and provisioning are allowed. As a rule, the resources used for backup are not used for traffic or provisioning.

Recovery can be executed for the whole system or only for a database partition. For more details on the backup and restore procedures, refer to CUDB Backup and Restore Procedures, Reference [3].

3.2.4   Import and Export

CUDB supports large-scale import and export operations for the entire database, or selected partitions, performed with the provided import and export tool commands.

Import operations can be optimized, for example, by using separate import files for different sets of data, divided by subscribers and applications. As such, a large amount of data can be imported simultaneously through multiple connections, minimizing time.

Export can be optimized by parallel execution of different partial exports, based on hierarchy or branch criteria, as well as filtering.

For more details on data import and export, refer to CUDB Import and Export Procedures, Reference [4].

3.2.5   Access Control

Access Control policies for LDAP, provisioning, and traffic can be dynamically configured through the definition of users, groups, and their associated set of data access privileges.

Access Control is performed when an application FE attempts to access subscriber data stored in CUDB, using data consumer authentication and data access authorization.

These privileges are set by using flexible Access Control Lists (ACLs) supporting regular expressions.

Access Control is performed based on the following factors:

3.2.6   Notifications

CUDB supports outbound notifications. When a piece of data is modified in a subscriber profile, CUDB can send Simple Object Access Protocol (SOAP) based notifications towards a configurable endpoint destination.

The support for notifications allows extensive configuration, including the following options:

Several receiver endpoints, that is, notification destinations, can be configured for every defined notification type. Based on the number of destinations, two types of notifications are available:

CUDB also enables individual SOAP-based notification connections to be protected with Transport Layer Security (TLS) / Secure Socket Layer (SSL).

For more details on notifications, refer to CUDB Notifications, Reference [5].

3.2.7   EPC Mobility Support

CUDB supports HLR and HSS/SLF interoperability based on notification services to notify application FEs on database updates in EPC mobility scenarios.

3.2.8   Geographical Zone Administration

Geographical zones offer customized data distribution, allowing the reduction of bandwidth across geographically distant CUDB sites using ad-hoc subscription distribution. Ad-hoc distribution is based on the zone concept shown in Figure 4.

Figure 4   Geographical Zone Administration Concepts

Individual subscribers are allocated to a zone based on customer choice, reducing data flow among areas. Each zone has its own independent storage and processing resources.

When a subscriber profile is created, the subscriber is assigned to a zone. The profile is, in general, accessed from the zone the subscriber was allocated to, keeping the network traffic local. For mobility scenarios, such as when the subscriber visits a different part of the country, the subscription data is transparently accessible. Smart zone use improves data access latency and network costs for large areas or between areas where data transport fees are expensive, as replication traffic is kept local to nodes within the zone.

For more details, refer to CUDB Multiple Geographical Areas, Reference [6].

3.2.9   BLOB Support

CUDB supports the definition of Binary Large Objects (BLOBs) in the data model. Each BLOB can be stored in the memory or on disk, based on individual configuration. For more information, refer to CUDB Binary Large Object Attributes Management, Reference [7].

3.2.10   External Data Access Support

Applications connected to CUDB can access any data stored by them and by other application FEs, with the proper access rights (see Section 3.2.5).

3.2.11   Subscription Reallocation

CUDB supports reallocating data from one DSG to another DSGs to ensure that all DSGs have optimal data occupancy.

Node-, site-, or zone-level data reallocation is also possible, through the proper handling of the origin and the target DSGs. The destination DSG does not have to be empty or belong to a different CUDB node.

For more details on reallocation, refer to CUDB Subscription Reallocation, Reference [8].

3.2.12   Geographically Redundant Deployments

Geographical redundancy allows storing copies of the same data in different CUDB nodes in different sites, providing a high redundancy and resiliency level. This function is available in the following two configurations:

Note:  
Standalone configuration without geographical redundancy is only supported for Customer Trial, Customer Test, and Ericsson Internal systems.

For more information on geographical redundancy, refer to CUDB High Availability, Reference [9].

3.2.13   Enhanced Overload Protection and Cooperative Load Regulation FE-BE

CUDB nodes incorporate self-protection mechanisms and internal load regulation between components, so that excessive incoming traffic (overload) does not lead to service interruption. If the overload is up to 150% of the engineered capacity, CUDB guarantees that at least 90% of the throughput at the engineered capacity is served.

CUDB is designed to withstand traffic peaks up to 300% of its engineered capacity.

CUDB nodes also support UDC Cooperative Load Regulation FE-BE, which provides automated traffic throttling in the overloaded UDC system. This is implemented in both the application FE and the BE, that is, CUDB,, and it is triggered by the application FE when the BE is facing difficulties handling the incoming traffic.

In overload situations, CUDB reports the overload status to the application FEs to trigger FE-BE Cooperative Load Regulation. After receiving overload notifications, the FE can initiate graceful throttling that limits traffic throughput in the UDC system, allowing CUDB to work at its engineered capacity and to handle the UDC system overload as fast as possible while maximizing service availability.

The FE-BE Load Regulation mechanism may occur in the following two ways:

Statistics about the rejected overload traffic are logged in the affected nodes.

3.2.14   Traffic Prioritization per Application under Overload

The "Traffic Prioritization per Application under Overload" function makes it possible to configure how CUDB handles incoming LDAP traffic from different application FEs when the DS layer is overloaded.

CUDB defines five priority levels under overload: one to five. LDAP users, representing application FEs, may be configured with a specific priority level through the overloadRejectionWeight attribute. Unless configured with a priority level, LDAP users keep the default priority level, which is one.

If database clusters are overloaded and traffic must be rejected, CUDB checks the priority level of the LDAP user issuing the LDAP request. Low-priority LDAP users will see their traffic more aggressively rejected than high-priority LDAP users. Traffic from high-priority LDAP users is processed at the expense of traffic from low-priority LDAP users. Thus, high-priority LDAP users have a higher successful-to-rejected traffic ratio than low-priority LDAP users.

The priority assigned to an LDAP user can be changed at any time, even in an overload situation. Priority-level changes take effect immediately.

3.2.15   Data Schema Management Tool

CUDB includes a Graphical User Interface (GUI) called the Data Schema Management Tool to manage the LDAP schema files. The tool allows the following operations:

The CUDB Data Schema Management GUI is included in the product by default. The tool handles LDAP schema files, but does not directly load schema files from the LDAP FEs running in the CUDB nodes.

The tool allows the following operations on schema files:

The following actions related to LDAP schema objects can also be performed:

The tool performs integration constraints validation in the schema files loaded in a project. The checked criteria are as follows:

The Data Schema Management Tool is executed on any Linux machine with Java or in the Operation and Maintenance (OAM) server blades installed in each CUDB node.

This GUI does not directly apply any schema change to a running node. Before proceeding with the schema updates, contact Ericsson personnel.

3.2.16   Consistency Check

CUDB Consistency Check is a basic function that looks for divergences in data stored on a slave PLDB or DSG replica, and the corresponding master replica, by scanning the database on both slave and master sides.

Consistency Checks can be ordered through the Command Line Interface (CLI), and their result is placed in output log files. Alarms are raised if data divergence is detected. Alarm severity level depends on the amount of inconsistency found.

For more details on CUDB Consistency Check, refer to CUDB Consistency Check, Reference [10].

3.2.17   Automatic Mastership Change

The Automatic Mastership Change (AMC) function serves the following purposes in CUDB:

For more information on the AMC function, refer to the Automatic Mastership Change section of CUDB High Availability, Reference [9].

3.2.18   Automatic Handling of Network Isolation

This functionality maximizes service availability in network isolation scenarios, reducing the chance of partial loss of service in an isolated site or sites during a network incident.

After a network isolation incident, CUDB preserves both data consistency and data durability using a sequence of automatically-triggered internal procedures, while ensuring service availability for end users.

During a network incident, CUDB can be split in two or more groups of CUDB sites with no communication between them.

A group with less than half of the sites in the CUDB system is called minority. A group with more than half of the sites is called majority.

In a symmetrical split, the system is split in two halves with the same number of sites in each group. In this case, the system is divided into two identical halves without minority or majority.

In an asymmetrical split, there are one or more minorities with or without a majority. Typically, but not necessarily, one majority with half or more than half of the sites exists.

CUDB handles such scenarios in different ways, providing different service availability per site based on the type of group each site belongs to: majority, half, or minority. System behavior and service maximization are described below:

When the network connectivity is recovered, CUDB exits multi-master mode if it was used. All data modifications from multi-master mode are identified and merged into the master to achieve the highest possible data durability.

After data repair is finished, CUDB automatically orders data backup in the current master replica and data restore in the current slave replica or replicas to synchronize data. Optionally, self-ordered backup and restore can be disabled by configuration to make it a manual step.

Once recovery is complete, geographical replication is immediately restarted.

Summarized Automatic Handling of Network Isolation provides the following:

Automatic repair is based on time stamps.

The Automatic Handling of Network Isolation function secures that provisioned data is never impacted or overwritten.

If the data repair functionality cannot resolve a conflict, such as the same LDAP entry being modified in two sites during the network incident, a report is generated identifying any LDAP entry that requires further investigation.

3.2.19   Provisioning Assurance after CUDB Mastership Change

This functionality preserves provisioning data durability following an unexpected or unplanned mastership change, to ensure service availability for end users.

Following a mastership change, CUDB automatically addresses the potential risk of having lost, or having only partially executed some provisioning operations. Such operations may have not been replicated in time to the new elected master before or during the mastership failover.

In such cases, CUDB informs the Provisioning Gateway to re-execute the affected operations, securing that any potentially lost or partially executed provisioning operation is properly recovered.

3.2.20   Multi-Application Support

CUDB on BSP 8100 (GEP5) platform includes multi-application support, which allows the following:

3.2.21   LDAP Data Views

The LDAP Data Views function makes it possible for application FEs to access data through a customized tree structure, called a custom DIT, with a custom schema. LDAP users can be configured to access CUDB either using the core DIT or to use a defined LDAP data view.

Multiple LDAP data views can be defined to accommodate application FEs.

Accessing CUDB through a data view applies some restrictions on the write operations, that is, add, delete, or modify, to guarantee the coherence of the core DIT data (for more information, refer to CUDB LDAP Data Views, Reference [11]). Ericsson strongly recommends that provisioning-type application FEs access CUDB through the core DIT.

LDAP data views are not available for export and import procedures or for notifications. Notifications must be configured according to core DIT Distinguished Names (DNs) and attributes. Data in SOAP messages are, likewise, to be identified by their core DIT DNs and attributes.

The LDAP Data Views function is included in the Application Facilitator Value Package.

3.2.22   VNF Support

The VNF Support function allows decoupling software and hardware through virtualization, enabling the harmonization of hardware across multiple products and vendors, and the optimization of hardware utilization.

Virtualization has benefits that change the way infrastructures and applications are deployed, used, maintained, and supported. It enables operators to move or deploy applications into the cloud.

The support of virtualization in CUDB is intended for early adopters of cloud technology.

VNF Support covers installation, configuration, and adaptation of CUDB OAM functions.

Virtualized CUDB provides the same functionality as a native CUDB system by:

CUDB is available through three different delivery models:

CUDB deliveries include the following:

It is possible to migrate a native CUDB system to a virtualized one using two different procedures:

CUDB supports the following workflows on the full Ericsson cloud infrastructure (ECEE & BSP 8100):

3.2.23   Flexible PL Deployment

The Flexible Processing Layer (PL) Deployment function allows the optimization of the number of PLDB servers in the system. Operators can decide the level of redundancy for PLDB per site, as long as at least one instance of PLDB is kept per site.

Until CUDB 1, a CUDB system consisted of a set of CUDB nodes of a single type. All nodes contained both a PLDB replica and one or more Data Store units.

With Flexible PL Deployment, it is possible to define nodes with only Data Store units and no PLDB replica. These nodes must not configured to receive direct traffic from application FEs.

This function allows the optimization of equipment in existing customers by:

The allowed CUDB deployments are:

Figure 5   Example of a CUDB System Setup with Flexible PL Deployment (one PLDB Instance per Site)

3.2.24   Local Reads

The Local Reads function makes it possible for application FEs to read data from the closest replica even if it is not a master replica The Local Reads function provides shorter response times, reduced traffic through the IP backbone, and a more efficient use of the available processing capacity since proxy traffic between CUDB nodes is minimized.

CUDB only allows local reads on slave replicas if the data there is recent enough, that is, the replication distance between the slave replica and its master is not greater than a configurable threshold. The threshold is defined per application FE or LDAP user.

The Local Reads function is configured per LDAP user, so it is possible to have application FEs with and without Local Reads in the same network. The Local Reads configuration for a given LDAP user can be changed at runtime without traffic disturbance.

Application FEs configured to use Local Reads can choose to override the Local Reads configuration, and perform a read on the master replica by an LDAP extension control, on a per LDAP request basis.

The Local Reads function is included in the Deployment Flexibility Value Package.

3.3   Security

CUDB supports the following interfaces over a secure protocol:

Authentication is supported by user credentials, that is,username and password, through the LDAP and OAM interfaces.

CUDB supports Simple Authentication, Security Layer (SASL) and TLS authentication for the LDAP interface.

Access to data can be limited using ACLs. For further information on ACLs, see Section 3.2.5.

It is possible to delegate authentication of OAM users to a properly configured external LDAP/LDAPS authentication server.

For more details on CUDB security, refer to CUDB Security and Privacy Management, Reference [12].

4   Interfaces

This section provides information on CUDB interfaces.

4.1   Reference Model

The interfaces and the protocols used within them are shown in Figure 6.

Figure 6   Reference Network Model

4.2   Protocols

A general outline of the protocols and the necessary stacks used by CUDB are depicted in Figure 7.

Figure 7   Protocols and Interfaces

The protocols used by CUDB and depicted in Figure 7 are as follows:

CUDB also makes use of the following internal protocols:

5   Architecture

This section describes the CUDB architecture from two different points of view: logical and hardware.

5.1   Logical Components

CUDB consists of the three logical components described in the following subsections.

5.1.1   PL

This component provides the following functions:

5.1.2   DS Layer

This component provides the following functions:

5.1.3   Monitoring and OAM Components

This component provides the following functions:

6   OAM

CUDB provides different interfaces for different administrative purposes, such as configuration and supervision. Focusing on customer needs, the goal is to provide operators with a flexible, cost-effective, and secure management system. CUDB offers OAM on a per node level.

Configuration management is supported through a CLI or NETCONF.

SNMP is used to provide FM alarms. For PM, statistics and logs are accessible through the SSHv2 suite of tools, like SFTP.

To visualize system status, the UDC Cockpit in User Profile Gateway (UPG) product provides a single, easy-to-use web interface.

6.1   Fault Management

Alarms are delivered through an SNMP flow to the Network Management System (NMS), allowing system administrators to detect faults and malfunctions in the node. Based on the alarm information, the system administrator can locate the event source and the documentation relevant to resolving or preventing failures. For more information on CUDB FM, refer to CUDB Node Fault Management Configuration Guide, Reference [14].

6.2   Performance Management

CUDB node elements generate statistics and counters, enabling the operator to monitor the performance of each CUDB node. Statistics are collected by internal performance components in each CUDB node and are made available to the NMS as standard 3GPP XML files. For more information on the related 3GPP standard, refer to 3GPP TS 32.435: Telecommunication Management; Performance Measurement: eXtensible Markup Language (XML) File Format Definition3GPP TS 32.435: Telecommunication Management; Performance Measurement: eXtensible Markup Language (XML) File Format Definition, Reference [24]. For further details on CUDB PM, refer to CUDB Performance Guide, Reference [15].

6.3   Log Management

CUDB node elements generate log files, enabling the operator to monitor events on each CUDB node. Logs can be easily collected by external management applications using SFTP.

Authentication and command logs can be sent to an external logging server.

For more details on CUDB logs, refer to CUDB Node Logging Events, Reference [16].

6.4   Configuration and Software Management

Both NETCONF and a CLI interface are available for handling CUDB node configuration. Configuration management is available through a Managed Objects tree with configurable parameters, or parameters that offer information on the status of certain components of CUDB, such as the status of a specific DS, or whether a specific DS is the master on its partition. CUDB includes tools to help define the initial Managed Objects tree and to verify if it is correct.

Certain CUDB operations are performed by executing ad-hoc commands.

Software inventory in a CUDB node shows all software package versions installed on each server of the CUDB node.

CUDB supports creating backups of the system configuration per CUDB node.

The LDAP Schema Management GUI ensures user-friendliness by providing a graphical interface to perform schema management operations, such as adding support for new applications. For further information, refer to CUDB LDAP Schema Management Graphical User Interface, Reference [17].

7   Configuration

Configuration of the system must take both the node level and the system level into account. Both levels are described in the following sections.

7.1   CUDB Node Configuration

A CUDB node consists of a maximum of 36 blades per cabinet or 36 VMs per VNF.

There are two types of CUDB nodes:

The components of nodes with PLDB are as follows:

The components of nodes without PLDB are as follows:

PLDB can be configured with any even number of servers between the minimum and maximum values. A larger PLDB size means that a lower number of DS units fits in nodes with a PLDB.

Note:  
For CUDB systems deployed on native BSP 8100 (GEP5), when the "BSP Capturing Unit Option" is used, the subrack capacity is decreased by two blades. For more information, refer to the BSP 8100 CPI.

7.2   CUDB System Configuration

CUDB supports several system configurations. Geographical redundancy can be set to either 1+1 or 1+1+1 modes. The maximum number of sites in a deployment is six. Figure 8 and Figure 9 show examples for all deployment types.

Figure 8   CUDB Deployment with Double Geographical (1+1) Redundancy

Figure 9   CUDB Deployment with Triple Geographical (1+1+1) Redundancy

During installation, CUDB can be deployed on either all-IPv4 or all-IPv6 network configurations.

Actual CUDB configurations must be set up according to the operator requirements after network planning. For further details, refer to CUDB Deployment Guide, Reference [18].

8   Characteristics

The following section highlights the most relevant characteristics of CUDB.

8.1   Availability and Reliability

The availability of CUDB is 99,999% at system level. The system is deployed with geographical redundancy; therefore, the service is not interrupted, even if a site is down. This is because the other CUDB sites keep processing traffic, thereby providing non-stop, uninterrupted data access.

CUDB architecture is also transparent from the data access point of view. Each CUDB node with a replica of PLDB provides access to the entire subscriber database, regardless of the data distribution across CUDB nodes. Data transparency is also supported by geographical redundancy. CUDB supports double or triple geographical redundancy (for more information, see Section 3.2.12).

Every element is replicated at least twice inside a CUDB node. In this way, single points of failure are avoided, and maintenance operations, such as replacing a failing switch or network card, can be performed without outage. Therefore, CUDB is continuously available during software and hardware upgrades.

Data is replicated between the DS units of a partition and inside a DS cluster. Each DS cluster holds two copies of the data stored on the partition.

Periodical backups can be ordered for the entire system.

8.2   Scalability

CUDB has a high-performance data layer that provides linear scalability both in capacity and performance, with bounded access latency. A CUDB system can increase the amount of stored data by adding further DSGs. This operation does not require downtime, and does not affect traffic. DSGs can be added by adding more server blades to the existing CUDB nodes, or by setting up additional CUDB nodes within the system.


Glossary

AAA
Authentication, Authorization and Accounting
 
ACL
Access Control List
 
AMC
Automatic Mastership Change
 
AuC
Authentication Center
 
BE
Back End
 
BLOB
Binary Large Object
 
BSP
Blade Server Platform
 
CLI
Command Line Interface
 
CUDB
Ericsson Centralized User Database
 
DIT
Directory Information Tree
 
DN
Distinguished Name
 
DS
Data Store
 
DSG
DS Unit Group
 
EIR
Equipment Identity Register
 
ENUM
E.164 Number Mapping
 
EPC
Evolved Packet Core
 
FE
Front End
 
FM
Fault Management
 
GEP3
Generic Ericsson Processor version 3
 
GEP5
Generic Ericsson Processor version 5
 
GUI
Graphical User Interface
 
HLR
Home Location Register
 
HSS
Home Subscriber Server
 
HTTP
Hypertext Transfer Protocol
 
HTTPS
Hypertext Transfer Protocol Secure
 
IETF
Internet Engineering Task Force
 
IMS
IP Multimedia Subsystem
 
IoT
Internet of Things
 
JMX
Java Management Extension
 
LDAP
Lightweight Directory Access Protocol
 
LDAPS
LDAP over SSL
 
M2M
Machine-to-Machine
 
MNP
Mobile Number Portability
 
NETCONF
Network Configuration
 
NMS
Network Management System
 
OAM
Operation and Maintenance
 
PG
Provisioning Gateway
 
PL
Processing Layer
 
PLDB
Processing Layer Database
 
PM
Performance Management
 
SAPC
Service-Aware Policy Controller
 
SASL
Simple Authentication and Security Layer
 
SFTP
Secure File Transfer Protocol
 
SLF
Subscription Locator Function
 
SNMP
Simple Network Management Protocol
 
SOAP
Simple Object Access Protocol
 
SSH
Secure Shell
 
SSL
Secure Socket Layer
 
TLS
Transport Layer Security
 
UDC
User Data Consolidation
 
UPG
User Profile Gateway
 
VNF
Virtualized Network Function

Reference List

CUDB Documents
[1] CUDB LDAP Interwork Description, 1/15519-HDA 104 03/10
[2] CUDB LDAP Data Access, 5/15534-HDA 104 03/10
[3] CUDB Backup and Restore Procedures, 1/1553-CNH 160 6130/10
[4] CUDB Import and Export Procedures, 6/1553-HDA 104 03/10
[5] CUDB Notifications, 9/15534-HDA 104 03/10
[6] CUDB Multiple Geographical Areas, 13/15534-HDA 104 03/10
[7] CUDB Binary Large Object Attributes Management, 2/15534-CRH 109 0494/10
[8] CUDB Subscription Reallocation, 12/15534-HDA 104 03/10
[9] CUDB High Availability, 7/15534-HDA 104 03/10
[10] CUDB Consistency Check, 17/1553-CSH 109 067/10
[11] CUDB LDAP Data Views, 15/15534-HDA 104 03/10
[12] CUDB Security and Privacy Management, 8/1553-HDA 104 03/10
[13] CUDB SOAP Interwork Description, 3/15519-HDA 104 03/9
[14] CUDB Node Fault Management Configuration Guide, 3/1553-CSH 109 067/10
[15] CUDB Performance Guide, 4/1553-HDA 104 03/10
[16] CUDB Node Logging Events, 4/1553-CSH 109 067/10
[17] CUDB LDAP Schema Management Graphical User Interface, 1/1553-CNH 160 6161/10
[18] CUDB Deployment Guide, 2/1553-HDA 104 03/10
[19] CUDB LDAP Interwork Description, 1/15519-HDA 104 03/10
[20] CUDB Glossary of Terms and Acronyms, 0033-HDA 104 03/10
Other Documents and Online References
[21] Lightweight Directory Access Protocol (LDAP). RFC 4510 http://www.rfc-editor.org/rfc/rfc4510.txt.
[22] The Secure Shell (SSH) Authentication Protocol. RFC 4252 http://www.rfc-editor.org/rfc/rfc4252.txt.
[23] NETCONF Configuration Protocol. RFC 4741 http://www.rfc-editor.org/rfc/rfc4741.txt.
[24] Telecommunication Management, Performance Measurement: eXtensible Markup Language (XML) File Format Definition. 3GPP TS 32.435 http://www.3gpp.org/ftp/Specs/html-info/32435.htm.


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