Hierarchical architecture
- Tier-1 ISP → Tier-2 ISP → Tier-3 ISP → Local ISP
graph TD
T1A[Tier 1 ISP A]
T1B[Tier 1 ISP B]
T2A[Tier 2 ISP A]
T2B[Tier 2 ISP B]
T3A[Local ISP A]
T3B[Local ISP B]
T3A -->|transit| T2A
T3B -->|transit| T2B
T2A -->|transit| T1A
T2B -->|transit| T1B
T1A <-->|peering| T1B
T2A <-->|peering| T2B
classDef tier1 fill:#ff9999
classDef tier2 fill:#99ff99
classDef tier3 fill:#9999ff
class T1A,T1B tier1
class T2A,T2B tier2
class T3A,T3B tier3
Use traceroute for finding probes between transit