Label distribution protocol(LDP) based virtual private LAN services(VPLS)has been widely used and is competitive to become the IETF standard of VPLS.

• 基于标签分布协议(LDP)的虚拟专用局域网(VPLS)是应用较广、得到众多厂商支持的一种VPLS方案,并且有望成为IETF标准。