SRC Learning Essentials Video Series, Preparing for the SRA certification exams: Inter-AS Model B VPRN. This video discusses the need for Inter-AS models to provide Layer-3 connectivity between VPN sites connected to different autonomous systems.   The video illustrates the operation of Inter-AS Model B and how it allows the exchange of VPN-IPv4 routes between the two ASBRs. Viewers will learn how to configure and verify an Inter-AS Model B VPRN on a Nokia Service Router.