Bonding with aggregation
Broadband bonding is a type of channel bonding that refers to aggregation of multiple channels at OSI layers at level four or above. Channels bonded can be wired links such as a T-1 or DSL line. Additionally, it is possible to bond multiple cellular links for an aggregated wireless bonded link.
Previous bonding methodologies resided at lower OSI layers, requiring coordination with telecommunications companies for implementation. Broadband bonding, because it is implemented at higher layers, can be done without this coordination.
Commercial implementations of Broadband Channel Bonding include:
- Mushroom Networks' Broadband Bonding Service 
- Connectify's Speedify fast bonding VPN – software app for multiple platforms: PC, Mac, ios and android 
- Peplink's SpeedFusion Bonding Technology 
- Viprinet's Multichannel VPN Bonding Technology 
- Elsight's Multichannel Secure Data Link 
- Synopi's Natiply internet Bonding Technology 
My journey for usable internet from worse to best on unstable lines:
Speedify on RPi -> OpenMPTCProuter(best of all for TCP only + aggregate) -> borrowed Peplink -> Glorytun UDP (bad with packet loss, even at 1% limiter) -> ExitLag -> Engarde (no aggregation), finally done 🙂
Bonding without aggregation
Site to Site Bonding
Ubiquity Edgerouter X on both ends
Ubiquity Edgerouter X