SCION Flashcards
Intra ISD Path Exploration
Beaconing:
- Core ASes initiate PCBs (Path-segment construction beacons) to traverse to lower ASes
- Each PCB represents a path from core to current AS
- PCBs are secured through origin auth. and MACs
Intra ISD Path registration
up path: AS selects path segments to announce as up-path segments for local hosts, registered at local path server
- AS selects path segments to announce as down-path segments for others, uploaded to core path server in Core AS
Path lookup (remote ISD)
- host queries RAINS server for address of H -> H:
- host contacts local path server to query path segments for -> up-path, core-path, down-path segments
remote ISD
- if local path server has down-path not cached ask core path server
- if core path server has down-path not cached ask remote core path server
- eventually local host gets up, core and down-path
Interface Identifiers
Each AS assigns integer number to each interface that connects to neighboring AS.
Use internal routing protocol to connect between ingress and egress SCION border router
Hop field MAC verification
based on local AS secret key
over timestamp, flags, Exp Time, Ingress, Egress, hop field of previous AS)
Core AS duties
- manage and distribute ISDs TRC
- Issue certs for all AS inside ISD
- provide connectivity to neighboring ISD
Low Latency connectivity
SCION can choose preferred path depending on application. Use low latency, low bandwith path for certain applications
Low Earth Orbit Satellite Network
Idea: use low orbit satellite to provide connectivity.
Problem: many satellites needed to provide full connectivity
SCION can integrate satellite network
control plane
deals with network topology and makes routing decisions. Responsible to discover paths, deal with route establishment, failures and policing.
data plane
responsible for packet forwarding that end hosts have injected into network. packets are forwarded based on routes established in the control plane.