Which service do you see deployed more often to customers ordering L2 VPN? VPLS or QinQ?
The document I have been reading states that QinQ has some advantages over VPLS. However, I have heard people talking a lot about VPLS deployment but I rarely see people talking about QinQ... just wondering.
You will see more offering on QinQ when your requirements are 'metro' connections, in other words, connecting locations within the metropolitan area.
QinQ requires the provider to have a switched backbone which is very hard to extend outside the metropolitan area.
VPLS, pseudowire, can be offered rather easier as it can be configured over IP/MPLS backbones by using ATOM or L2TPv3.