What is the solution for interprovider Option B connection between LDP-based Layer 2 circuits and BGP-based Layer 2 VPNs?
As of Junos OS Release 9.3 and later, Layer 2 circuits with interworking iw0 interfaces can be manually stitched. If dynamic signaling is needed, use FEC 129 multisegment pseudowires if you are not using BGP-based Layer 2 VPNs. In Junos OS Release 11.2 and later, FEC 129 is supported.
For more information, click Layer 2 VPNs and VPLS Feature Guide.