China Telecom Individual Cisco Systems Huawei Technologies New H3C Technologies This document specifies the procedures for distributing Border Gateway Protocol-Link State (BGP-LS) key parameters for inter-domain links between two Autonomous Systems (ASes). It defines a new type within the BGP-LS Network Layer Reachability Information (NLRI) for an Inter-AS Link, along with three new Type-Length-Values (TLVs) descriptors for the BGP-LS Inter-AS Link. These extensions and procedures allow network operators to collect inter-domain interconnect information and automatically compute the inter-AS topology using information provided by the BGP-LS protocol.