APN-Configuration-Profile  AVP ( 1429 )

The APN-Configuration-Profile AVP shall contain the information related to the user's subscribed APN configurations for EPS. The Context-Identifier AVP within it shall identify the per subscriber's default APN configuration. The Subscription-Data AVP associated with an IMSI contains one APN-Configuration-Profile AVP. Each APN-Configuration-Profile AVP contains one or more APN-Configuration AVPs. Each APN-Configuration AVP describes the configuration for a single APN. Therefore, the cardinality of the relationship between IMSI and APN is one-to-many.

Reference: 3GPP TS 29.272-f70   View