Ethernet Tunnels can provide G.8031 Ethernet APS protection as described in G.8031 Protected Ethernet Tunnels, or they can operate in a load-sharing manner providing an emulated LAG function. Moreover, as multiple Ethernet Tunnels can be provisioned on the same physical links, it is possible that two physical links could support one or more Ethernet Tunnels supporting APS protection for protected services whilst concurrently supporting one or more Ethernet Tunnels in load-sharing mode for non-protected services.
When Ethernet Tunnels have the protection type set to load-sharing, the precedence is configured to secondary, making the tunnels equal to implement load-sharing capability. A path threshold parameter allows the load-sharing group to be declared down if the number of paths drops equal to or lower than the threshold value. The ‛lag-emulation’ context provides access to conventional LAG parameters such as the adapt-qos mode (link, port-fair or distributed bandwidth distribution) and per-fp-ing-queuing to ensure that only one ingress queue is instantiated for every physical link supported on the same FP complex.
A typical use case for LAG emulation is to allow unprotected Ethernet services to capitalize on the LAG capability. RSTP and MSTP can also be used to network VPLS or B-VPLS over the Ethernet tunnels. LAG Emulation is also recommended when you use BGP-MH site support for Ethernet tunnels.