5. Conclusions and outlook

Among L2VPN technologies, VPLS competes with VPWS (point-to-point L2VPN). VPLS is more suitable for providing Layer 2 Ethernet connection services with a large network of customer sites. VPWS quickly reaches its limits in such cases, due to the complexity of configuration between L2VPN PE routers and a control plane that is difficult to supervise. VPLS solves this problem through the use of its VPLS MAC address tables and architectures adapted to the services, allowing good scaling. In some cases, the number of MAC addresses to be supported by VPLS PE routers can become problematic (unlike VPWS, which doesn't use MAC addresses), but some new emerging technologies come to the aid of VPLS, such as PBB-HVPLS, which enables client MAC addresses to be hidden from VPLS core routers.

VPLS is particularly well suited to enterprise or wholesale services. Indeed, its great...