Contents
1 Introduction
This Network Impact Report (NIR) describes how the Virtual Call Session Control Function (vCSCF) 1.11.0 with new and enhanced commercial features affects the vCSCF 1.10.x. The NIR also describes the impact on the overall network, including all affected products and functions.
In this document, the term "vCSCF" refers to the product and the term "CSCF" refers to the CSCF application, independent of being deployed in a native or virtual environment.
- Note:
- The vCSCF product is a software-only product. It is not bundled with any hardware platform or virtualization software.
This document covers the following enhanced features:
- 3rd Party Registration
- OAM Management (Virtualized)
- Offline Charging
- P-CSCF Restoration
- Traceability and Troubleshooting
- User Initiated Registration/Deregistration
- VNF-LCM Workflows
2 General Impact
This section describes the general impact because of the introduction of the vCSCF 1.11.0.
2.1 Backward Compatibility
The vCSCF is backward compatible.
The previous non-backward compatible EATF changes are removed.
2.2 Capacity and Performance
The subscriber capacity decreases slightly by the introduction of the vCSCF 1.11.0 if the same version of cloud environment is used.
The network performance is not affected by the introduction of the vCSCF 1.11.0.
2.3 Hardware and Platform
The vCSCF is a software-only product.
The demands on the hardware and platform are specified in Virtual CSCF Infrastructure Requirements.
2.4 Upgrade Impact
Smooth upgrade is supported for the vCSCF 1.10.x – vCSCF 1.11.0 upgrade.
2.5 Deprecated Features
There are no deprecated features.
2.6 Other Network Elements
The Northbound Interface (NBI) is modified, which may affect external management systems, for example the Operation and Support System Radio and Core (OSS-RC).
3 Interfaces
This section describes interface changes between the existing and new revisions of the product. The changes to interfaces described here can require changes to the operator systems, technical plans, training of operator personnel, and so on.
No impact indicates that no changes are needed.
3.1 Inter-Node Interface
The changes to the inter-node interfaces are listed in Table 1.
The description of impact is as follows:
- No Impact means that the new version can be installed without affecting other nodes.
- Minor Impact means that there are changes, but with extra configuration the previous behavior can be kept.
- Major Impact implies that the change has made an interface backward incompatible.
- New Interface indicates that the interface did not exist in the previous revision.
- Obsolete means that the interface no longer exists.
|
Interface |
Protocol |
Impact |
Description of Change Compared To vCSCF 1.10.x |
|---|---|---|---|
|
No Impact |
Redistribution of application server traffic in CSCF is enhanced by configuration of the parameter scscfReregAsEntry. |
3.2 Operation and Maintenance
This section describes changes to attributes, alarms, SNMP alerts, and counters.
3.2.1 Provisioning and Configuration
This section lists changed, deleted, and new attributes.
Further information on attributes can be found in the following documents:
3.2.1.1 Changed Attributes
There are no changed attributes.
3.2.1.2 Deleted Attributes
There are no deleted attributes.
3.2.1.3 Deprecated Attributes
There are no deprecated attributes.
3.2.1.4 Obsolete Attributes
There are no obsolete attributes.
3.2.1.5 New Attributes and Environment Variables
The new attributes are described in Table 2.
The new environment variables are described in Table 3.
|
Attribute Name |
Description |
|---|---|
|
3rd Party Registration | |
|
scscfReregAsEntry |
Each entry in this multi-value attribute holds an IP address of an AS instance. For these IP addresses, CSCF invokes 3rd party registration for re-registration when a 3rd party registration trigger is configured in the service profile of a user even if the Registration Type is not configured with re-registration. An empty list means that the function is disabled. |
|
New Environment Variable |
Description |
|---|---|
|
Offline Charging | |
|
CSCF_CHARGING_BACKUP_RETRY_LIMIT |
This parameter defines the maximum number of retries to back up an offline charging request. After all retries fail, the charging information is lost. Together with parameter CSCF_CHARGING_BACKUP_RETRY_TIMER_INTERVAL, this parameter defines how long time the charging information is cached in the memory at most, but not more than 10 minutes. The value 0 disables caching of the charging information at backup failure. Range: 0–5 Default value: 3 |
|
CSCF_CHARGING_BACKUP_RETRY_TIMER_INTERVAL |
This parameter defines the time interval between two retries to back up an offline charging request. Together with parameter CSCF_CHARGING_BACKUP_RETRY_LIMIT, this parameter defines how long time the charging information is cached in the memory at most, but not more than 10 minutes. Unit: s Range: 10–180 Default value: 20 |
3.2.2 Fault Management
This section describes alarms that have been changed, deleted, or added.
3.2.2.1 Changed Alarms
The changed alarms are described in Table 4.
|
Alarm Name |
Description of Change |
|---|---|
|
Offline Charging | |
|
CSCF Charging Backup File System Unavailable |
The value of Additional Text is changed to Backup Write Failure or Backup Disk Full. |
3.2.2.2 Deleted Alarms
There are no deleted alarms.
3.2.2.3 Deprecated Alarms
There are no deprecated alarms.
3.2.2.4 Obsolete Alarms
There are no obsolete alarms.
3.2.2.5 New Alarms
The new alarms are described in Table 5.
|
Alarm Name |
Description |
|---|---|
|
OAM Management (Virtualized) | |
|
C-Diameter, Diameter Measurement Threshold Crossed |
This generic C-Diameter threshold-based alarm was raised because at the end of the Granularity Period the measured value for one of the DiameterCC measurement types was higher than the configured threshold. |
|
C-Diameter, Peer Connection Congestion |
This generic C-Diameter threshold-based alarm indicates congestion in the Own or in the Peer Diameter Node. The congestion was measured on one of the peer connections, that is, the message amount dropped because the diameter link congestion crossed the threshold defined by the related threshold job level. |
|
C-Diameter, RTT to Remote Node Exceed Limits |
This generic C-Diameter threshold-based alarm indicates disturbances in egress request message delivery. That is, the message amount dropped because the time-out crossed the threshold defined by the related threshold job. |
3.2.3 Events and Notifications
This section describes events and notifications that have been changed, deleted, or added.
3.2.3.1 Changed Events and Notifications
There are no changed events and notifications.
3.2.3.2 Deleted Events and Notifications
There are no deleted events and notifications.
3.2.3.3 Deprecated Events and Notifications
There are no deprecated events and notifications.
3.2.3.4 Obsolete Events and Notifications
There are no obsolete events and notifications.
3.2.3.5 New Events and Notifications
There are no new events and notifications.
3.2.4 Counters
This section describes counters that have been changed, deleted, or added.
3.2.4.1 Changed Counters
There are no changed counters.
3.2.4.2 Deleted Counters
There are no deleted counters.
3.2.4.3 Deprecated Counters
The deprecated counters are described in Table 6.
|
Counter Name |
Description |
|---|---|
|
OAM Management (Virtualized) | |
|
cscfActiveUsers |
The measurement status of the PM counter cscfActiveUsers is set to DEPRECATED. |
|
cscfActiveUsersPerProfile |
The measurement status of the PM counter cscfActiveUsersPerProfile is set to DEPRECATED. |
3.2.4.4 Obsolete Counters
There are no obsolete counters.
3.2.4.5 New Counters
The new counters are described in Table 7.
|
Counter Name |
Description |
|---|---|
|
OAM Management (Virtualized) | |
|
DiaNode |
This C-Diameter Performance Management group consists of 49 new counters. For more information, see Managed Object Model (MOM). |
|
DiaPeer |
This C-Diameter Performance Management group consists of 49 new counters. For more information, see Managed Object Model (MOM). |
|
DiaPeerConn |
This C-Diameter Performance Management group consists of 49 new counters. For more information, see Managed Object Model (MOM). |
4 Summary of Impacts per Feature
This section summarizes the impact per feature when the feature is turned off, as listed in Table 8.
The description of impact is as follows:
- Major Impact means that the feature has done an incompatible change so that another node requires an update.
- Minor Impact means that the feature has caused changes that affect other nodes, but with extra configuration, the previous behavior can be kept.
- No Impact means that the feature has no impact on the system.
|
Feature |
Impact |
Basic or Optional New or Enhanced |
Included in Value Packs and Basic Packs |
Relation to Other Features or Nodes | ||
|
Major |
Minor |
No | ||||
|
3rd Party Registration |
X |
Basic Enhanced |
Voice Messaging Service Identity SIP Trunking Dynamic User |
|||
|
OAM Management (Virtualized) |
X |
Basic Enhanced |
Voice Messaging Service Identity SIP Trunking Transit Dynamic User |
|||
|
Offline Charging |
X |
Basic Enhanced |
Voice Messaging Dynamic User SIP Trunking Service Identity |
Charging Control Function | ||
|
P-CSCF Restoration |
X |
Optional Enhanced |
Voice Messaging Service Identity SIP Trunking Dynamic User |
|||
|
Traceability and Troubleshooting |
X |
Basic Enhanced |
Voice Messaging Service Identity SIP Trunking Transit Dynamic User |
|||
|
User Initiated Registration/Deregistration |
X |
Optional Enhanced |
Voice Messaging Service Identity SIP Trunking Dynamic User |
|||
|
VNF-LCM Workflows |
X |
Optional Enhanced |
Voice Messaging Service Identity SIP Trunking Transit Dynamic User |
|||
5 Impact on CSCF Features
This section shows the impact on the CSCF features when the feature is turned on.
5.1 3rd Party Registration
This section describes the enhanced feature 3rd Party Registration.
5.1.1 Description
This enhancement enables 3rd party registration when an AS needs to redistribute users to another AS instance because of different reasons. In most cases, the 3rd party registration trigger is not configured for re-registration, which prevents traffic from being redistributed in time. This problem is solved by enabling the CM parameter scscfReregAsEntry.
Redistribution of AS traffic is only needed when AS caching is used, meaning when the parameter as-profile is set to 1 in the service profile of a user.
Each entry in the multi-value attribute scscfReregAsEntry holds an IP address of an AS instance. For these IP addresses, CSCF invokes 3rd party registration for re-registration requests when a 3rd party registration trigger is configured in the service profile of a user even if the Registration Type is not configured with re-registration.
An empty scscfReregAsEntry list means that this function is disabled.
When the traffic handover to the target AS node reaches the desired level, the scscfReregAsEntry for the specific AS is disabled.
5.2 OAM Management (Virtualized)
This section describes the enhanced feature OAM Management (Virtualized).
5.2.1 Description
eVIP is configured by pushing predefined eVIP configurations to the CSCF with the Parameter Database (PDB) tool.
New Diameter Stack
The C-Diameter stack is integrated with the vCSCF and removed from vDicos. It is backward compatible, but there are some additional O&M-related enhancements.
Three new alarms, C-Diameter, Diameter Measurement Threshold Crossed, C-Diameter, Peer Connection Congestion, and C-Diameter, RTT to Remote Node Exceed Limits are added. For more information, see Section 3.2.2.5 New Alarms.
New Diameter throughput/latency Performance Management counters are introduced, see Section 3.2.4.5 New Counters.
Log Management Framework
With the introduction of the Log Management (LogM) framework, centralized registered log stream management through the Northbound Interface (NBI) is possible. This includes setting the severity filter, performing a manual export of logs, and configuring automatic streaming of log entries towards a log server.
5.3 Offline Charging
This section describes the enhanced feature Offline Charging.
5.3.1 Description
Backup Handling
The Additional Text of alarm CSCF Charging Backup File System Unavailable is updated to indicate that the alarm occurs when backing up charging requests fail because of disk full or disk writing failure.
When the charging backup file system fails to back up charging requests because of disk full or disk writing failure, the charging requests are cached in the memory for a predefined time. During the predefined time, the system retries to back up charging requests for predefined times. After all retries fail, the charging requests are lost.
5.4 P-CSCF Restoration
This section describes the enhanced feature P-CSCF restoration.
5.4.1 Description
The condition to trigger the P-CSCF restoration procedure in S-CSCF is expanded from only triggering when access types contain the strings 3GPP-GERAN, 3GPP-UTRAN, or 3GPP-E-UTRAN, to also trigger when they contain 3GPP-NR.
5.5 Traceability and Troubleshooting
This section describes the enhanced feature Traceability and Troubleshooting.
5.5.1 Description
CSCF Health Check Single Sign-On Support
The vCSCF supports Single Sign-On for the CSCF health check to align with the health check functions of the other IMS nodes to simplify the use of the Core Network Operations Manager (CNOM).
5.6 User Initiated Registration/Deregistration
This section describes the enhanced feature User Initiated Registration/Deregistration.
5.6.1 Description
The S-CSCF stores the content of the PVNI header of a selected contact in the originating SIP INVITE request. Any PVNI content stored in REGISTER of the same contact is overwritten by the S-CSCF. Stored PVNI content is not removed if there is no PVNI header in the incoming INVITE.
5.7 VNF-LCM Workflows
This section describes the enhanced feature VNF-LCM Workflows.
5.7.1 Description
Time-Based Scaling
The Managed Scaling workflow can be also triggered for time-based scaling on VMware.