tier-1 Internet provider networks with multiple peering points

Approximate backbone topologies of the largest Internet providers together with geographical locations of the POPs and Exchanges, and approximate long-distance link delays.

The models contain fully configured routers that run BGP4 (external and internal) and OSPFv2. Two or more geographically overlapping backbones can be configured to peer at the specified peering locations.

These models can be easily further elaborated by attachment of customer networks at distinct POPs, either for the studies of routing, or to study the traffic, or both.

The topology diagrams below roughly preserve the relative geographic locations of major routers; but "lift" one network above another in order to illustrate the BGP peering links. In reality, the peering routers usually sit one next to another in an Internet Exchange or a peering hotel.

SSFNet Configuration Files:
The set of three DML files, us.dml, ibgp.dml, and dictionary.dml describe configuration specifications in a modular format.

The largest fraction of the DML specs is used for configuration of the BGP and OSPF sessions in the routers.

Requires the latest version of OSPFv2.

Download all files:


US tier-1 provider backbone models. The topology approximates the AT&T network topology (green), and the Worldcom network topology (blue). The routers are placed in the major POPs. The same two backbone network model, now with BGP peering sessions (red links) at the Internet exchanges in Washington DC, Dallas TX, Chicago IL and San Francisco CA.