BVDSL or bonded VDSL is a technique used to bond two VDSL copper wire pairs for the purpose of increasing the capacity of the VDSL link, as well as extending the copper network’s reach.
First of all, you must ensure that the device you are using supports VDSL bonding. Devices such as Cisco’s 800 series ISRs with the appropriate IOS support it. Some example configurations can be found here:
As for a leased line WAN link, it depends upon the nature of the leased line. If it is simply an uncharged circuit (a passive wire pair without any active components such as DSLAM, switches, or routers), then you would have to create an xDSL or serial connection between the two customer premises devices themselves. This depends on the equipment you have and the ports they possess. It also depends on the leased line total distance, as xDSL will operation only for distances of several kilometers. If the leased line is active, that is, if it has intermediary devices sending signals, then you must determine what technology is being used (xDSL, serial, frame relay etc) so that you can configure your endpoints appropriately.
Hopefully, this gives you some idea of how to proceed from here. If you have any more questions, feel free to let us know!
A dialer is an interface you create in a Cisco router that is used for any connection that uses PPP settings. This is the case for xDSL connections, as well as for cellular connections for example. You can see two examples of such dialer interfaces created in the following lessons:
That dialer interface essentially takes care of the authentication and the various other parameters such as encapsulation and the PVCs being used.
The VDSL2 bonding is something that takes place at a lower level. Once bonding is configured as shown in the link in the previous post, then you can apply the dialer to the VDSL interface as normal. For more info on how that is done, take a look at the following documentation: