This document describes the usage of the Border Gateway Protocol (BGP) to establish Transparent LAN Services (TLS) tunnels across Autonomous System (AS) boundaries. TLS is described in [MARTINI- SIG] and [LASSERRE-TLS]. The focus of this document is to explain how to achieve the tunnel LSP between Provider Edge (PE) routers in different ASes. The method described herein may also be used in [BGP-VPN] implementations.