Access Point Name (APN) is a logical name referring to an external packet data network and/or to a specific service that the subscriber wishes to connect to.

Virtual APNs allow differentiated services within a single APN.

The Virtual APN feature allows a carrier to use a single APN to configure differentiated services. The APN that is supplied by the MME is evaluated by the P-GW along with multiple configurable parameters. Then, the P-GW selects an APN configuration that is based on the supplied APN and those configurable parameters.

APN configuration controls all aspects of a session at the P-GW. Different policies imply different APNs. However, after basic APN selection, internal reselection can occur based on the following parameters:

• Service name

• Subscriber type

• MCC-MNC of IMSI

• Domain name part of username (user@domain)

• S-GW Address

A call received on a particular APN can be redirected to another APN through a Virtual APN, based on a given criteria.

An APN received in the Create Session Request is called Gn APN, and the APN selected as part of a Virtual APN selection is called Gi APN.

Currently, the GGSN, P-GW, SAEGW non-CUPS products support Virtual APN selection that is based on the following modes:

• Local Configuration based

• Gx based

• RADIUS based

• Location based (for GGSN calls)

The P-GW/SAEGW deployed in CUPS mode also supports similar functionality to use the feature in network deployments.

The Virtual APN feature is supported as a forward compatible to CUPS architecture-based P-GW/SAEGW nodes. Since the feature is being supported incrementally, following methods can be used to select Virtual APN for CUPS-based gateway nodes:

• Local Configuration based

• Gx based

• Location based (for GGSN calls)

Important

The CLI commands available for non-CUPS Virtual APN feature is applicable in CUPS environment.

Following are sample configuration for:

1. Control Plane node:

   configure 
      context context_name 
         apn apn_name 
            pdp-type ip_address 
            bearer-control-mode mixed 
            selection-mode sent-by-ms 
            ims-auth-service service_name 
               exit 
            ip access-group acl_group_name in 
            ip access-group acl_group_name out 
            authentication pap preference chap preference allow-noauth 
            ip context-name context_name 
            virtual-apn preference preference apn apn_name 
            bearer-access-service  service_name 
            cc-profile  cc_profile_index 
            [ pdp-type { ipv4 | ipv6 | ipv4v6 } ] 
            [ roaming-mode { home | roaming | visiting } ] 
            [ serv-gw-plmnid mccmcc_number mnc mnc_number ] 
            end 
   
   

   Note

   bearer-access-service service_name : Specifies the Bearer Access Service (GGSN/P-GW/Other) name. This service name is unique across the context. service_name must be an alphanumeric string of 1 through 63 characters. cc-profile cc_profile_index : Specifies the charging characteristics (CC)-profile index. cc_profile_index must be an integer from 1 to 15. [ pdp-type { ipv4 | ipv6 | ipv4v6 } ] : Configures pdp-type rule. The available options include: ipv4 : Configures VAPN Rule for IPv4. ipv4v6 : Configures VAPN Rule for ipv4v6. ipv6 : Configures VAPN Rule for IPv6. [ roaming-mode { home | roaming | visiting } ] : Supports separate PDP context or PDN connection processing for roaming, visiting, and home subscribers. serv-gw-plmnid : Specifies the Serving Gateway PLMN ID.

   
   configure 
      context context_name 
         apn apn_name 
            pdp-type ipv4 ipv6 
            bearer-control-mode mixed 
            selection-mode sent-by-ms 
            ims-auth-service service_name 
               exit 
            ip access-group acl_group_name in 
            ip access-group acl_group_name out 
            authentication pap preference chap preference allow-noauth 
            ip context-name context_name 
            end 

   • For Gx-based Virtual APN selection:

     configure 
        context context_name 
           ims-auth-service service_name 
              policy-control 
              diameter encode-supported-features virtual-apn 
              end 

   • For Location-based Virtual APN Selection for GGSN Calls:

     configure 
        context context_name 
           apn apn_name 
              virtual-apn preference priority apn vapn_name routing-area-code-range from start_value to end_value 
              end 

2. User Plane node:

   configure 
      context context_name 
         apn apn_name 
            ip context-name context_name 
            end 
   
   configure 
      context context_name 
         apn apn_name 
            ip context-name context_name 
            end