TCP Fast Open (TFO) is an extension to speed up the opening of successive TCP connections between two endpoints. It works by using a TFO cookie (a TCP option), which is a cryptographic cookie stored on the client and set upon the initial connection with the server. When the client later reconnects, it sends the initial SYN packet along with the TFO cookie data to authenticate itself. If successful, the server may start sending data to the client even before the reception of the final ACK packet of the three-way handshake. Due to this RTT between SYN-ACK and ACK is calculated based on difference between SYN-ACK packet and first uplink ACK packet.

The Event Data Record feature in CUPS has the following limitations:

• EDR will be generated only for flow end condition – idle timeout, hagr, normal flow termination & during end of session.

• Charging-Action based EDR configuration is not supported.

• Reporting EDRs are not supported.

Use the following configuration to push EDRs from CP to UP using PFD mechanism.

Note	The CLI commands used in this configuration are part of the existing non-CUPS architecture.

active-charging service service_name 
   rulebase rulebase_name 
      flow end-condition { timeout | normal-end-signaling | session-end  | interim   } charging-edr charging_edr_format_name 
      edr transaction-complete http charging-edr charging_edr_format_name 
      exit 
      edr-format format_name 
         attribute attribute_name 
         end 

NOTES:

• flow end-condition : This command allows you to configure the end condition of the session flows related to a user session and triggers EDR generation.

• timeout : Creates an EDR with the specified EDR format whenever a flow ends due to a timeout condition.

• normal-end-signaling : Creates an EDR with the specified EDR format whenever flow end is signaled normally.

• session-end : Creates an EDR with the specified EDR format whenever a subscriber session ends. By this option session manager creates an EDR with the specified format name for every flow that has had any activity since last EDR was created for the flow on session end.

• charging-edr charging_edr_format_name : Specifies the charging EDR format.

• interim : This condition specifies the interim threshold condition of the flow where an EDR is generated based on the configured timer value. The interim_timer_value is configured in minutes with a configurable range from 15 to 1440 minutes.

• The interim keyword is only applicable for new flows created and not on existing flows.

• http : Specifies HTTP protocol related configuration.

Use the following configuration to enable EDR module on UP

Note	The CLI commands used in this configuration are part of the existing non-CUPS architecture.

configure 
   context context_name 
      edr-module active-charging-service 
      end 

Prior to using the following CLI commands to configure additional TCP fields in the EDR, ensure that all the other EDR configurations are present.

Note	For CUPS setup, once configuration is present on CP side, push those changes on UP using push config-to-up all command from CP.

configure 
   active-charging service service_name 
      edr-format edr_format_name 
         [ no ] rule-variable tcp syn_synack_rtt priority 3 
         [ no ] rule-variable tcp syn_synack_ack_rtt priority 4 
         end 

The following fields are displayed in support of this feature:

• Rulebase Name

  • EDRs

  • Charge Volume

    • Uplink Pkts

    • Uplink Bytes

    • Downlink Pkts

    • Downlink Bytes

  • Charging EDRs

    • Total Charging EDRs generated

    • EDRs generated for handoff

    • EDRs generated for timeout

    • EDRs generated for normal-end-signaling

    • EDRs generated for session end

    • EDRs generated for rule match

    • EDRs generated for hagr

    • EDRs generated for flow-end content-filtering

    • EDRs generated for flow-end url-blacklisting

    • EDRs generated for content-filtering

    • EDRs generated for url-blacklisting

    • EDRs generated for any-error packets

    • EDRs generated for firewall deny rule match

    • EDRs generated for transaction completion

    • EDRs generated for voip call end

    • EDRs generated for dcca failure handling

    • EDRs generated for TCP optimization on

    • EDRs generated for tethering signature change

    • EDRs generated for interim interval

    • Total Flow-Overflow EDRs

    • Total zero-byte EDRs suppressed

  • EDRs generated for interim

    • Interval

• Total Rulebases

The following fields are displayed in support of this feature:

• Rulebase Name

• Charging EDRs

  • Total Charging EDRs generated

    • EDRs generated for handoff

    • EDRs generated for timeout

    • EDRs generated for normal-end-signaling

    • EDRs generated for session end

    • EDRs generated for rule match

    • EDRs generated for hagr

    • EDRs generated for flow-end content-filtering

    • EDRs generated for flow-end url-blacklisting

    • EDRs generated for content-filtering

    • EDRs generated for url-blacklisting

    • EDRs generated for any-error packets

    • EDRs generated for firewall deny rule match

    • EDRs generated for transaction completion

    • EDRs generated for voip call end

    • EDRs generated for dcca failure handling

    • EDRs generated for TCP optimization on

    • EDRs generated for tethering signature change

    • EDRs generated for interim interval

    • EDRs generated for audio-end Sessions

    • EDRs generated for video-end Sessions

    • EDRs generated for voipout-end Sessions

    • Total Flow-Overflow EDRs

    • Total zero-byte EDRs suppressed

The following fields are displayed in support of Additional TCP Fields in EDR feature:

• Service Name

  • EDR Format Name

    • rule-variable tcp syn-synack-rtt priority 3

    • rule-variable tcp synack-ack-rtt priority 4

The following bulk statistic(s) are added in the ECS schema to support Event Data Records in CUPS:

• edrs-generated: Indicated the total number of EDRs generated.