Billing Introduction

The Call Accounting Manager (CAM) generates Call Detail Records (CDRs) and supports accounting events logging to the SBC Core. The SBC provides the ability to map CDR fields and other input parameters to Remote Authentication Dial In User Service (RADIUS) attributes (standard as well as vendor-specific attributes) and send to the appropriate RADIUS server.

SBC Core supports to configure one remote server per SBC for the purpose of authenticating users from this server using RADIUS protocol. The username and encrypted password are sent to the remote RADIUS server in an ACCESS_REQUEST packet. The user is allowed/denied access to the SBC based on the response from the RADIUS server. 

SBC users are currently segregated into the following groups which define the privileges of each user. Access to data/commands is allowed/prevented based on the group of the user who is trying to acquire the access.

• Administrator
• Operator
• FieldService
• Guest
• SecurityAuditor
• Calea

Since the RADIUS protocol does not provide a means to assign users to a group, the implementation currently hard codes every RADIUS authenticated user to the Administrator group.

For detailed information on RADIUS authentication, refer to Configuring SBC for RADIUS Authentication.

Viewing Billing Records 

As calls traverse the SBC, Call Detail Records (CDRs) are generated and stored in /var/log/sonus/evlog/evlog directory. You can view these CDR by looking at files with the “.ACT” extension. It is useful to view these ACT logs during call debugging (to get the originating trunk group, calling and called numbers, codec used, etc.).

You may also view billing records (and other logs) from the EMA Platform Mode. Refer to Administration - Accounting and Logs for more information.

When downloading billing records (or other logs), you must use port 2024 to SFTP files off of the SBC.

Call Detail Record Format

This section describes the ASCII and streaming Call Detail Record (CDR) format.

Various Sonus elements such as GSX 9000, PSX, and SBC use many of the same CDR fields. Because of this, some fields in the “Accounting Records” table below do not apply to SBC call details, but instead simply indicate pass-though type messages (for example, ISUP and PSTN fields).

For more information on known limitations, refer to the applicable release notes at SBC Release Information page.

Accounting File Version

The CAM version of SBC release V06.02.00 is 87.00.00 (major CAM version is 87, minor CAM version is 0, special CAM version is 0). The associated hex format of the CAM file version is "00570000" as shown in below header example.

Sonus Networks, Inc.00000000FF600000570000000000000060V06.02.00 00000000000000000000000000000000000ACT2017071715113200000000000000.

File Header

Every event log file, including accounting logs, contains a file header. This header consists of a 128-character string terminated by a carriage return. Each field in the event log file header is defined in the following table:

File Footer

The one line footer, below, is appended to each log file (including accounting logs) when the file is closed under controlled conditions.

DDMMYYYY HHMMSS: File administratively closed.

Controlled conditions include CLI commands (for example, set oam eventLog typeAdmin acct rolloverAction...) and automatic roll-overs when maximum file size is reached.

When an uncontrolled file closure occurs, such as an SBC switch-over or system failure, this footer may not be present.

How to Set Up SFTP from SBC to a CDR Server

If the CDR server is configured, SBC transfers the files through SFTP to the configured destination.

1. To create the CDR server, use the following command syntax:

   % set oam accounting cdrServer admin [primary | secondary] connectionTimeout <numeric: 15 to 600 seconds> filePrefix <name of SBC> ipAddress <ip address> password <password for ftp user> path <directory to ftp to> transferTimeout <numeric: 15 to 600 seconds> username <username of ftp user>

     An example to show the CDR server configuration and check the configuration is as follows:

   admin@SBC01> config
   admin@SBC01% set oam accounting cdrServer admin primary connectionTimeout 15 filePrefix SBC01 ipAddress 10.10.211.10 password sonus path /export/home/SBC01ACTrecs/ transferTimeout 15 username root
   admin@SBC01% commit
   admin@SBC01% quit
   
   admin@SBC01> show table oam accounting cdrServer admin
                                                                                   FILE    CONNECTION  TRANSFER
   TYPE     IP ADDRESS    USERNAME  PASSWORD         PATH                          PREFIX  TIMEOUT     TIMEOUT
   --------------------------------------------------------------------------------------------------------------
   primary  10.10.211.10  root      $3$qaO71mBy8l8=  /export/home/SBC01ACTrecs/  SBC01   15          15
   [ok][2013-10-02 06:14:49]
   admin@SBC01>

    

2. Initially, the accounting field is not set to ftp or automatically roll over. Use the following command to view Rollover setting for accounting (See "acct" row in the example):

   admin@SBC01> show table oam eventLog typeAdmin
                                    MESSAGE                                                                        FILE                SYSLOG   SYSLOG    SYSLOG  RENAME
                      FILE   FILE   QUEUE    SAVE  FILTER  ROLLOVER START       ROLLOVER                 ROLLOVER  WRITE     SYSLOG    REMOTE   REMOTE    REMOTE  OPEN
   TYPE      STATE    COUNT  SIZE   SIZE     TO    LEVEL   TIME                 INTERVAL  ROLLOVER TYPE  ACTION    MODE      STATE     HOST     PROTOCOL  PORT    FILES
   -------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   system    enabled  16     16000  32       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   debug     enabled  16     16000  32       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   trace     enabled  16     16000  32       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   acct      enabled  16     64000  32       disk  info    -                    0         nonrepetitive  stop      optimize  disabled  0.0.0.0  tcp       514     disabled
   security  enabled  16     16000  32       disk  major   -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   audit     enabled  32     2048   10       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   packet    enabled  32     2048   10       disk  major   -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   [ok][2013-10-02 06:41:58]

    

3. To create the accounting file rollover and ftp, use the following command syntax:

   % set oam eventLog typeAdmin acct rolloverStartTime <CCYY-MM-DDTHH:MM:SS> rolloverInterval <number of seconds between each file rollover> rolloverType repetitive rolloverAction start
   where 'T' in 'DDTHH' is a constant used to indicate the Time follows.

     An example of the configuration and display of the accounting file rollover and ftp is as follows:

   admin@SBC01% set oam eventLog typeAdmin acct rolloverStartTime 2013-10-02T06:30:00 rolloverInterval 900 rolloverType repetitive rolloverAction start
   [ok][2013-10-02 06:41:25]
   [edit]
   admin@SBC01% commit
   Commit complete.
   [ok][2013-10-02 06:41:28]
   [edit]
   admin@SBC01% quit
   admin@SBC01> show table oam eventLog typeAdmin
                                    MESSAGE                                                                        FILE                SYSLOG   SYSLOG    SYSLOG  RENAME
                      FILE   FILE   QUEUE    SAVE  FILTER  ROLLOVER START       ROLLOVER                 ROLLOVER  WRITE     SYSLOG    REMOTE   REMOTE    REMOTE  OPEN
   TYPE      STATE    COUNT  SIZE   SIZE     TO    LEVEL   TIME                 INTERVAL  ROLLOVER TYPE  ACTION    MODE      STATE     HOST     PROTOCOL  PORT    FILES
   -------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   system    enabled  16     16000  32       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   debug     enabled  16     16000  32       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   trace     enabled  16     16000  32       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   acct      enabled  16     64000  32       disk  info    2013-10-02T06:30:00  900       repetitive     start     optimize  disabled  0.0.0.0  tcp       514     disabled
   security  enabled  16     16000  32       disk  major   -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   audit     enabled  32     2048   10       disk  info    -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   packet    enabled  32     2048   10       disk  major   -                    0         nonrepetitive  stop      default   disabled  0.0.0.0  tcp       514     disabled
   [ok][2013-10-02 06:41:58]

    

4. View CDR Server status using the following command:

   admin@SBC01> show table oam accounting cdrServer status
                              SUCCESSFUL  FAILED     PENDING
   TYPE     STATE   PROGRESS  TRANSFERS   TRANSFERS  TRANSFERS
   -------------------------------------------------------------
   primary  active  done      3           0          0
   [ok][2013-10-02 07:27:19]

    

5. Verify that the files were transferred to the FTP server by logging in to the CDR server and executing the following command:

   ftp server:
   root@hostname # pwd
   /export/home/SBC01ACTrecs
   root@hostname # ls -l
   total 708
   -rw-r--r--   1 root     other     346730 Oct  2 06:45 SBC01.20131002064500.1000022.ACT
   -rw-r--r--   1 root     other        175 Oct  2 07:00 SBC01.20131002070000.1000023.ACT
   -rw-r--r--   1 root     other        175 Oct  2 07:15 SBC01.20131002071500.1000024.ACT
   root@hostname #

    

6. Execute the following command to view the successful and failed CDR file transfer:

   % show table oam accounting cdrServer status
                              SUCCESSFUL  FAILED     PENDING
   TYPE      STATE  PROGRESS  TRANSFERS   TRANSFERS  TRANSFERS
   ---------------------------------------------------------
   primary   active  done     2           0          0
   secondary standby idle     0           7          0

SBC Standard Attributes

The SBC RADIUS application uses standard attributes from the RADIUS when possible. For CDR fields that cannot be mapped to the standard attributes, vendor-specific attributes are defined. The SBC allows instances of the standard attributes in Accounting request message as per following table:

SBC accounting records may be sent to three different locations:

1. Local hard disk—If accounting is enabled, then ASCII records are always written to the local disk.
2. An external server:
   
   1. To DSI-L0 server—If configured, the ASCII records are transferred to the external Sonus DSI server through SFTP.
   2. To external billing server from IMS network via Rf Interface.
3. RADIUS server—RADIUS accounting records can be generated and sent to an external RADIUS server.

Accounting File Roll-Over

The SBC application maintains a configurable maximum of up to 1024 accounting files. Once the configured limit of files is reached, the application deletes the oldest files first to accommodate the new files.

When accounting file names reach the maximum value of 1FFFFFF.ACT, the next file name rolls over to 1000001.ACT. Use the “Rename Open Files” flag to rename the most recent accounting file with the ”ACT.OPEN” extension. This flag is accessible from the EMA at “System Configuration” > “CDR and Servers” tab.

Global Charge Reference

The Global Charge Reference (GCR) feature allows correlation of calls across networks where the calls are originated from and terminated at different third-party devices. The GCR field is populated in the CDRs of the SBC if the GCR is received in a gateway protocol message from a GSX9000.

The GSX9000 receives or generates the GCR parameter through an ISUP parameter. The GCR is used in conjunction with SIP call-id’s to associate calls that interwork between SIP and ISUP protocols across multiple network devices.

RADIUS Support

RADIUS is a standardized protocol for supporting Authentication, Authorization, and Accounting (AAA) management in a distributed client-server architecture. The SBC acting as a RADIUS client can send call-accounting records to an external RADIUS server. For a description of Sonus CDR to RADIUS VSA field mapping, refer to Managing CDR Records.

The following message types are supported by RADIUS protocol:

• Accounting Request
• Accounting Response
• Access-Request
• Access-Accept
• Access-Reject

The accounting request and its response for a transaction methodology is described below.

• The SBC sends an accounting-request with Accounting-Status-Type value "Accounting-on". At a later time, this transaction informs the server about the new accounting client that will send the accounting messages to the NAS/resource usage by user.
• When the SBC connects the call, the accounting starts. The accounting-request contains the Accounting-Status-Type with the value "Start". The "Start" records contains the following:
• User identification
• Network address
• Point of attachment
• Unique session identifier
• Next, the SBC records the status change by NAS to the RADIUS server for this active session. The accounting-request now contains the Accounting-Status-Type with the value "Interim". The interim record usually conveys the current session duration and information on the current data usage.
• When the user network access is closed, the NAS issues a final Accounting Stop record to the RADIUS server, providing the information on the final usage in the terms of the following:
• Time
• Packets transferred
• Data transferred
• Reason for disconnect
• Other information related to the call

The accounting-request contains the Accounting-Status-Type with the value "Stop". The primary purpose of this data is to bill the user. The data is also used for statistical purposes and for general network monitoring.

RADIUS Client-Server Diagram

Renaming Open Accounting Files

The SBC includes the ability to rename a currently-open accounting file using a known suffix to make it easily identifiable by external applications. To activate this feature, simply enable the flag “Rename Open Files” using EMA GUI or CLI. 

CLI syntax example:

% set oam eventLog typeAdmin acct renameOpenFiles enable

Once this flag is enabled, on the next accounting file open activity, the suffix .OPEN is appended to the filename using the format <shelf><sequence number>.ACT.OPEN (currently open files are not affected).

For example, as accounting file 1000099 is created with this feature already enabled, the file is named “1000099.ACT.OPEN”.

For configuration details, refer to:

• CLI: Event Log - CLI
• EMA: Event Log - Type Admin

Rf Interface Support

The SBC Core acting as a P-CSCF or IBCF supports Rf interface-based offline billing in compliance with standard IMS as well as file-based and stream-based CDRs. The SBC can select either CDR/streaming-based charging or Rf Interface depending on whether the system-wide flag, enableRfApp, is enabled or not. Refer to Signaling - Global - CLI or Signaling - Diam Sig Controls for configuration details.

The SBC Diameter node supports both Rf application along with the existing Rx application. The Diameter node uses "Route Table" to find peer for outbound request based on destination realm and application.

For more details, refer to Rf Interface Support page in the Managing CDR Records section.

CDR Server Remote Port Configuration

The SBC supports transferring the call accounting files (.ACT) to the CDR server through a user configured port. The SBC also supports using the Secure Shell (SSH) public keys instead of password to authenticate with the remote CDR server.

The following parameters are added in CDR server configuration to set remote port and ssh key based authentication:

• cdrPort
• useSshKeyFile


• generateSshPublicKeys

To generate a new SSH public key, execute the following command:

% request oam accounting cdrServer admin primary generateSshPublicKeys

The generated SSH public key must be installed on CDR server to use ssh key based authentication from SBC. The SSH public key must be copied to the remote CDR server file /home/<user>/.ssh/authorized_keys. If the private key is compromised, the key must be re-generated. Once the key is re-generated, the CDR server must be updated with the new key.

Configuring CDR Server Remote Port

% set oam accounting cdrServer admin primary cdrPort 2024

1. Enabling SSH Key Based Authentication
2. Generating the SSH Public Key
3. Copying and Installing the SSH Public Key to CDR Servers

Enabling SSH Key Based Authentication

To enable SSH key based authentication, execute the following command:

% set oam accounting cdrServer admin primary useSshKeyFile Enable

Generating the SSH Public Key

To generate a new SSH public key, execute the following command:

% request oam accounting cdrServer admin primary generateSshPublicKeys
result success
reason 
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDclSOlVfVmmhatw5bDQRk7AaYvCRUUfHHbSvkCBb4T8zYdJ8JNw15rMSKk9hEkVdtEEZRJU4Q97C+3LbPknZrIMM+zmSRYmh2/LkGAlydSJ+sPe9i7zWFOLYeA3gitaKJSPgSjdb4WGgDq686Ei4yup9xYDbT8wAcosQsf3tfbqH2GetNJ8tAs3KjRi7FPhH1hHdXVyH0yW1mdGlMYvoFUeFCRjhE81oJhy2jMTJD9T3eQiJo4NZQZYOgALMQPi8fxaAgnuWmvrejNTn/PgRyGpQEs7HFHkX5zHW5M74PU/Z3S3Y2uSZlYrCQRf9Y2mUiK5R40bjsKz4TqIP5LfzhX
[ok]

Copying and Installing the SSH Public Key to CDR Servers

The SSH public key is copied to the remote CDR server file /home/<user>/.ssh/authorized_keys.

For configuration details, refer to Accounting - CLI.