SBc services support the Differentiated Services Code Point (DSCP) marking functionality. DSCP marking helps in packet traffic management. DSCP marking can be performed on both IPv4 and IPv6 packets leaving the SBc interface.

Either the predefined DSCP values can be used for marking or any arbitrary value ranging from 0x01 to 0x3F can be assigned. The default DSCP value is 0x00 or be (Best Effort). The default DSCP value is automatically set when the configuration is disabled.

config 
   context context_name  
      sbc-service service_name  
         [ no ] ip qos-dscp dscp_value 
         end 

NOTES:

• ip : Defines the Internet Protocol parameters for the packets leaving through the SBc interface.

• qos-dscp : Designates the Quality of Service - Differentiated Services Code Point value to the packet leaving through the SBc interface.

• dscp_value : Value assigned to the packet for DSCP marking. The value can be a predefined DSCP value or an arbitrary value ranging from 0x01 to 0x3F.

In compliance with 3GPP TS 29.168 v15.1.0, the MME supports the following procedures:

• Write-Replace Warning Procedure

• Stop Warning Procedure

• Error Indication Procedure

• Write-Replace Warning Indication Procedure

• Stop Warning Indication Procedure

• PWS Failure Indication

• PWS Restart Indication

This section describes the known limitations for the Cell Broadcast Center feature:

• The size of the SBc message supported by MME is a maximum of 50K bytes. If MME receives the WRITE-REPLACE WARNING REQUEST over 50K bytes, the message cannot be processed, and a warning syslog is generated.

• MME supports only up to 256 maximum elements in PWS Restart-TAI-List. If the eNodeB sends more than 256 elements, the PWS Restart Indication message does not get relayed to the CBC.

The Cell Broadcast Center feature complies with the following standards:

• 3GPP TS 22.268 v10.4.0: Public Warning System

• 3GPP TS 23.041 v10.6.0: Technical realization of Cell Broadcast Service (CBS)

• 3GPP TS 29.168 v15.1.0: Cell Broadcast Centre Interfaces with the Evolved Packet Core

• 3GPP TS 36.413 v15.3.0: S1-AP Interface

An SBc service must be created within a context to configure the SBc-AP interface to accept connections from one or more CBCs.

Important

A valid license key is required to access the commands used to configure and manage the SBc interface. Contact your Cisco account representative for license information.

Use the following configuration to create and configure the SBc service.

configure 
   context ctxt_name 
      sbc-service sbc_svc_name 
         associate sctp-param-template sctp_param_template_name 
         bind ipv4/v6-address ipv4/v6_address_value1 ipv4-address ipv4_address_value2 
         cbc-associations maximum number 
         sbc-mme sctp port port_num 
         end 

NOTES:

• Up to 8 SGs + MME + SBc + SLs services can be configured on the system. The SBc service name must be unique across all contexts.

• Associating the SBc service to the SCTP parameter template is not required for the SBc service to be operational. However, if a template is associated, the template must exist before the SBc service is associated to it.

• The SBc service must be bound to at least 1 IP address. Up to 2 IPv4 or 2 IPv6 addresses can be specified for multihoming purposes.

• The cbc-associations command is used to define the maximum number of CBC connections allowed for this SBc service. The default setting is 1. Up to 2 connections are allowed per SBc service.

• The default SCTP port used is 29168. The MME listens for incoming SBc-AP connections from an CBC on this port.

Use the following configuration to associate the SBc service to an MME service.

configure 
   context ctxt_name 
      mme-service mme_svc_name 
         associate sbc-service sbc_svc_name [ context ctxt_name ] 
         end 

NOTES:

• Each MME service can be associated with one unique SBc service.

• The SBc service is not a critical parameter for the MME service. Removing this configuration will not restart the MME service.

• The MME will always check for a valid SBc service that is up and connected to a CBC before performing any meaningful operations on the Warning Messages received on the S1-AP interface (like attempting to forward the messages).

• Use the optional context keyword if the SBc service and MME service are configured in separate contexts.

• The SBc service is not operationally STARTED unless the MME service to which it is associated is in a STARTED state.

Use the following configuration timeout values for aggregating responses received from eNB at MME.

config 
    context context_name 
          sbc-service service_name  
             enb-response-aggr-timer timeout_value 
            [ default ] enb-response-aggr-timer  
            end 

• enb-response-aggr-timer timeout_value : Configures the timeout value in seconds for aggregating responses received from eNB at MME.

• timeout_value : must be an integer between 4 and 120.

• default : Sets the default timeout value for aggregating responses received from eNB at MME. Default value is 10 seconds.

Use the following configuration to enable or disable the warning indication messages towards CBC from MME.

config 
    context context_name 
          sbc-service service_name  
             [ no | default ] send stop-warning-ind  
             [ no | default ] send write-replace-warning-ind  
            end 

• send stop-warning-ind : Enables the stop warning indication messages towards CBC from MME.

• send write-replace-warning-ind : Enables the write-replace-warning indication messages towards CBC from MME.

• no : Removes the configuration of sending the warning indication [ stop warning / write replace warning ] messages towards CBC from MME.

• default : Sets the default configuration of sending the warning indication [ stop warning / write replace warning ] messages towards CBC from MME. By default sending of warning indication messages are disabled.

The following command displays configuration information for all SBc services, for the specified for the specified SBc service, or for the specified Cell Broadcast Center.

show sbc-service { all | cbc-associations { all | sbc-service-name sbc_svc_name [ path-info | summary ] } | sbc-service-name sbc_svc_name }  

The following command displays the SBc Service name and SBc Service Context which has been associated with each MME service.

show mme-service all 

The following command displays configuration errors and warnings related to all SBc services on the MME:

show configuration errors section sbc-service verbose 

The following traps are available to track status and conditions relating to the SBc service.

The following traps are generated to track status and conditions of individual CBC associations.

SBc service related bulk statistics are provided within the SBc schema.

Use the following command to display a list of all variables available within this schema:

show bulkstats variables sbc 

For more information about these statistics, refer to the SBc Schema chapter of the Statistics and Counters Reference.

show sbc statistics

The following command displays all statistics related to the SBc service. These statistics can be filtered based on CBC association (peer-id) or SBc service name.

show sbc statistics { all | peer-id peer_id | sbc-service-name sbc_svc_name } 

show mme-service statistics s1ap

The following command displays S1-AP statistics related to the SBc interface. See the lines for Kill Request and Kill Response in the example below:

 
S1AP Statistics: 
   Transmitted S1AP Data: 
 
       Kill Request: 0    Write-Replace Warning Request: 0 
   Received S1AP Data: 
 
       Kill Response: 0   Write-Replace Warning Response: 0 

Event logging for the SBc interface can be enabled using the following command:

logging filter active facility sbc level severity_level 

See the System Logs chapter of the System Administration Guide for more information about event logging.