Our view of A/L Active Nodes
 
 
Programmes from Trusted Source
- Can be cache with only specific or tested progs
 
Best employed for optimisation
- Optimise end-end services otherwise unfeasible
 - Need fail-safe operation of active nodes
 - Have soft state
 
Now used in several applications
- Web-Proxy caching nodes, Mbone tunnel end-points, 6bone tunnels
 
May need Hard-state Inter security domains