cnSGW-C supports interaction of eMPS with GTPv2 load or overload feature. It supports excluding eARPs, APNs, Emergency, or WPS calls during self-protection mode in GTPv2 load or overload feature.

By default, cnSGWc throttles the incoming GTPC messages in the self-protection mode. If cnSGWc is in self-protection mode and the overload exclude profile is configured, then the cnSGWc compares the parameters of the incoming message with the configured DNN, ARP, QCI, and message priority values.

In case of a match or the session is identified as a WPS or an emergency session, cnSGWc processes the incoming message, otherwise rejects it.

cnSGW-C can exclude the dnn-list, arp-list, and qci-list, message-priority from the rejection for incoming request messages in self-protection mode. cnSGW-C excludes this rejection in the following manner:

• Excludes the dnn-list from rejection for any call level procedure when the subscriber APN name (NI+OI) matches with overload-exclude-profile.

• Excludes bearer modification or creation from rejection for any new or existing ARP (Priority-Level) value.

• Excludes bearer modification or creation from rejection for any new or existing QCI value.

• Excludes the deleted bearer or the session operations, such as, Delete Bearer Request, Delete Session Request, Delete Bearer command from rejection irrespective of the overload-exclude-profile configuration.

To exclude the incoming GTPC traffic from a specific north-bound interface, see the Configure Overload Exclude Profile section.

Note	cnSGW-C does not support message throttling.

Priorities determine the order in which service requests are dequeued by a server. For example, the priority that client assigns to individual services can range from 0 to 15, where 0 represents the highest priority.

In cnSGW, the cnSGW service sends the Inter-process Communication (IPC) message to the protocol pod for Wireleass Priority Service (WPS) session using Priority IPC Stream.

cnSGW creates the message-priority profile to define priorities either at global level or at each interface level (PFCP, GTP). You can select the Message Priority value based on:

• ARP and QCI received in Bearer context in the Create Session Request (CSR), Create Bearer Response (CBR), and Create Session Response.

• Update Message priority value based on ARP and QCI received in Bearer context in the Update Bearer Request (UBR).

cnSGW supports the following functionalities:

• WPS sessions per Roaming partner.

• Exclusion of WPS sessions from overload throttling.

• Session type conflict resolution at cnSGW.

• WPS sessions handing at UPF over Sxa Interface for collocated subscriber.

• WPS session monitoring.

Operators can monitor the S-GW service statistics for WPS users and users can also monitor number of active WPS sessions.

Message Priority Functions

The Message Priority mechanism functions are:

• MP (gtp, pfcp) is copied to transactions created for handling an incoming message and the same is copied to child transactions. These priority values are also copied into IPC metadata to send it across to destination pods.

• Protocol pods (protocol, gtp) detect the incoming messages as WPS messages based on the message priority available in the incoming message. These message protocol pods use priority IPC streams toward a service pod.

Conditions for Message Priority Profile Selection

The following conditions apply for Message Priority Profiles selection:

• Subscriber-policy must define group of subscriber and associated Operator policy.

• Operator policy must define the associated DNN policy.

• DNN policy must define a list of DNN and the associated DNN profile.

• DNN profile must have an associated QoS profile name and WPS Profile name.

• QoS Profile must have an associated message-priority-profile.

• If the message-priority-profile is configured in WPS Profile and in S-GW QoS Profile for DNN, then the message-priority-profile configured in WPS profile takes priority.

• If any message priority configuration is changed at run time, it is applicable for the new calls. For existing calls, new configuration is applicable when the Bearer is updated or a new Bearer is added.

• The existing Message Priority gets displayed in outbound messages that are selftriggered, for example, DDN.

• If an incoming PDN level GTP message such as CSReq, MBReq, DSReq, CBReq, DBReq, UBReq is received with valid message priority and if copy-incoming is set to true for any of the Bearers in that PDN, then the received messages priority gets copied in all the outgoing GTP/PFCP messages that are triggered by that incoming message.

• If an incoming UE level GTP message such as HO DSReq, RAB is received with valid message priority and copy-incoming is set to true for any of the bearers in the PDN, then the received message priority will be copied in all outgoing GTP/PFCP messages(for that PDN) triggered by that incoming message.

• If an incoming PFCP message such as Session report is received with valid messages priority and copy-incoming is set to true for any of the Sx bearer in that Sx session, then received messages priority gets copied in outgoing response messages.

Message Priority Selection Logic

• Messages priority value is displayed in outgoing messages based on the following logic:

  • GTP Messages:

    • For PDN level messages: If a PDN have multiple bearers which are marked as WPS (having different GTP message priorities), in that case highest messages priority (0 is highest and 15 is lowest) will be copied into outgoing GTP messages.

    • For UE level GTP messages: If UE have multiple bearers which are marked as WPS (having different GTP message priorities), in that case the highest messages priority(0 is highest and 15 is lowest) will be copied into outgoing GTP messages.

  • PFCP Messages: If a Sx session has multiple bearers, which are marked as WPS (having different PFCP message priorities), in that case the highest messages priority (0 is highest and 15 is lowest) gets copied into outgoing PFCP messages.

The following is an example configuration.

config
   profile wps wp1
     arp 2 message-priority-profile message_priority_name
   end

To verify the configuration:

show full-configuration profile wps wps1
profile wps wps1
arp 2 message-priority-profile mp1
exit

The following is an example configuration.

config
   profile sgw sgw1
     wps-profile wp1
     end

To verify the configuration:

show running-config profile sgw
profile sgw sgw1
wps-profile wp1

The following is an example configuration.

 config
   profile dnn dnn1
   wps-profile wps1
   end

To verify the configuration:

show running-config profile dnn 
profile dnn dnn1
wps-profile wps1