The GTPP Endpoint is an App-infra-based service that enables the GPRS Tunneling Protocol Prime (GTPP) protocol functionality for the SMF service. The SMF with Legacy Interfaces supports the GTPP Charging (Gz) interface in the GTPP Endpoint.

For offline charging, the Gz is the reference point from a Charging Data Function (CDF) to the CGF for transporting of CDRs.

The GTPP Endpoint provides the following support to the SMF service:

• Handles the usage and event accounting at a Bearer level and the accounting information gets stored as part of the subscriber session.

• Generates CDR content from this accounting information and then transfers to the GTPP Endpoint. The GTPP Endpoint is responsible for encoding the received CDRs into ASN.1 (based on the configured dictionary).

• Sends the received CDRs to the CGF server using the GTPP protocol.

For more information on this feature, see the UCC 5G SMF Configuration and Administration Guide > GTPP Endpoint chapter.

Following are the Information Elements (IEs) supported for the Gz support with GTPP feature.

The GTPP endpoint support complies with the following Charging specific 3GPP standards:

• 3GPP TS 32.251 "Telecommunication management;Charging management;Packet Switched (PS) domain charging"

• 3GPP TS 32.295 "Telecommunication management; Charging management; Charging Data Record (CDR) transfer"

• 3GPP TS 32.297 "Telecommunication management; Charging management; Charging Data Record (CDR) file format and transfer"

• 3GPP TS 32.298 "Telecommunication management; Charging management; Charging Data Record (CDR) parameter description"

The following are the limitations in the SMF with Diameter Interfaces Charging feature:

• The SMF with Diameter Interface does not support Local storage mode, TCP, and Redirect Request or Responses.

• The SMF with Diameter Interfaces supports only the custom24 CDR Dictionary.

• In case of switchover, only the new CDR Send Request buffer is checked on the new standby GTPP pod.

• In case of switchover, only the new archive is checked on the new stand by GTPP pod.

• In case of double fault, old archive CDR and old Send Request buffer are lost.

To configure the GTPP profile, use the following configuration:

config 
   profile gtpp-profile profile_name gtpp 
      dictionary 
      ignore  ignore_value 
      instance-id 
         charging-agent address IPv4_adress port UDP_port 
         server{ cgf address IPv4_adress max-cdrs max_cdrs { node-alive Enable | Disable}
               port UDP_port priority priority deadtime time_interval 
               echo-interval  echo_interval timeout timeout_val max-retry 
               max_retry max-pdu-size max_pdu_size wait-time time_interval } 
      local-storage 
      mode 
         local 
         streaming-parallel 
      cgf-server-redundancy-support 
     exit 
  exit 
exit 

NOTES:

• dictionary : Specify a dictionary for ASN.1 based encoding of a CDR.

• ignore ignore_value : Specify the configuration to ignore the echo-rc-change. This CLI control option provides a flexibility to detect a CGF path failure due to a change in the echo response RC.

• instance-id : Specify the instance ID of a GR instance.

  • charging-agent : Configure the charging agent.

    • addressIPv4_address : Specify the IP address of the interface configured within the endpoint that is used to transmit CDR records to the CGF.

    • port : Specify the UDP port.

      Note

      The Charging agent IP address and port configured in GTPP profiles should also be configured in the endpoint gtpprime under the Gz interface. The Runtime configuration update of the Charging agent IP address and port is not recommended. Ensure to add new profile with new Charging agent IP address and port.

  • server : Configures server details.

    • cgf : Configure the CGF server with the following parameters:

      • address IPv4_address: Enter the IPv4 address of CGF server, using dotted-decimal notation range.

      • max : Configure maximum number of unacknowledged CDRs for a CGF. Must be an integer ranging from 1 to 2000.

        Note	The runtime configuration change of max is not recommended. Follow the Method of procedure:

        1. Delete the cgf having old max and then commit the change.

        2. Add the cgf again with a new max value.

      • node-alive Enable | Disable : Enable or disable sending Node Alive Request to a GTPP Server (such as CGF).

      • port : Specify which port that the CGF is using.

      • priority : Specify the relative priority of this server when system is selecting which CGF server to use.

  • deadtime : Configure the deadtime in seconds. Must be an integer ranging from 1 to 65535. Default value is 120.

  • max-cdrs : Designate the maximum number of CDRs in a GTPP message. Must be an integer ranging from 1 to 255.

  • max-pdu-size : Designate the maximum size of the PDU, in bytes. Must be an ranging from 1024 to 1460.

  • timeout : Specify the number of times the system attempts to communicate with a CGF that is not responding.

  • wait-time : Specify the time to wait before sending the GTPP request.

• local-storage : Specify local storage details.

• mode : Specify a storage mode to be used.

  • local : Specify the use of HDD to store CDRs

  • streaming-parallel : Specify the use of HDD to store CDRs, if CGF fails. When CGF comes up, stream the CDRs to the CGF. Streaming is in a parallel and newly generated CDRs are sent to CGF along with CDRs streamed from HDD.

• cgf-server-redundancy-support : Enable or disable the CGF server redundancy support per GTPP profile. By default this configuration is disabled.

Configuration Example

The following is an example configuration for GTPP profile.

profile gtpp-profile pf2 gtpp
 dictionary custom24
 mode       streaming
 cgf-server-redundancy-support disable
 instance-id 1
  charging-agent
   address 10.10.10.205
   port    3386
  exit
  server
   max-pdu-size  1460
   timeout       30
   max-retry     3
   max-cdrs      5
   wait-time     30
   echo-interval 60
   deadtime      120
   cgf address 10.10.10.80 port 3386 max 100 priority 1 node-alive disable
   cgf address 10.10.10.90 port 3386 max 100 priority 2 node-alive disable
  exit
 exit
exit

Note

GTPP-EP pod uses this configuration. GTPP-EP pod always ignores nodes configuration. When the k8s single-node is set to false, it spawns two replicas of a GTPP-EP pod in active or standby mode, which is independent of replicas and nodes configuration. When the k8s single-node is set to true, the configured replicas have its impact. When the k8s use-volume-claim is set to true, endpoint GTP prime is used to set the storage size limit. Default value of storage size limit is one GB. When the system is up and running, we can't change the storage size.

To configure a GTPP endpoint, use the following commands:

config 
 instance instance-id instance_id 
   endpoint gtpprime 
      storage storage_capacity 
      replicas replicas_count 
      nodes nodes_count 
      interface Gz  
        vip-ip   vip_ip vip-port vip-port vip-interface vip-interface vrf vrf  
      end 

NOTES:

• endpoint gtpprime : Specifiy the following parameters to configure an endpoint:

  • storage storage_capacity —Specify the storage size of persistent volume in GB. Must be an integer in the range of 1-100.

    Note	CLI doesn't allow changing storage size while the system is running. To change the storage size, bring the system down first.

  • replicas replicas_count —Specify the number of replicas per node. Must be an integer.

  • nodes nodes_count —This property is ignored. You may skip configuring it.

  • interface Gz : Configure the Gz interface details, such as vip IPv4 address, vip port, vip interface, and virtual routing and forwarding details.

    Note	When the system is active and under the Gz Interface, if there are any add or update vip configurations to use new values, ensure to restart the udp-proxy.

Configuration Example

The following is an example configuration for the endpoint gtppprime configuration:

instance instance-id 1
 endpoint gtpprime
  replicas 1
  nodes    1
  storage  1
  interface gz
   vip-ip 10.10.10.205 vip-port 7202 vip-interface v303 vrf GTPP-VRF
  exit
 exit
exit