Concepts

Upstream Provider

An ISP or carrier that offers IP Transit services to another network. It connects you to the global Internet.

Downstream Customer

The network or organization that buys IP Transit to access the Internet.

BGP (Border Gateway Protocol)

The routing protocol used to exchange routing information between different networks (Autonomous Systems). It allows IP Transit providers and customers to communicate routing updates.

Autonomous System (AS)

A collection of IP networks managed by a single organization with a unified routing policy. Each AS is assigned a unique AS number (ASN).

Delivery Mode

Routing Mode (Static / BGP)

Specifies how routing information is exchanged between your network and the transit provider:

• Static Routing Routes are manually configured and fixed. Simple but not scalable.

• BGP (Border Gateway Protocol) A dynamic routing protocol that automatically exchanges routes between Autonomous Systems (ASes). Scalable and flexible, commonly used for IP Transit.

Gateway Mode

Refers to the device or role acting as a gateway between your network and the upstream transit provider. It handles traffic forwarding, routing decisions, and possibly BGP sessions.

BFD (Bidirectional Forwarding Detection)

A fast failure detection protocol used with routing protocols (like BGP) to quickly detect link or path failures. Helps minimize downtime by triggering fast rerouting.

• Transmit Interval: How often BFD packets are sent (e.g., 300 ms).

• Receive Interval: Expected interval at which BFD packets are received from the peer.

• Detection Multiplier: Number of missed packets before considering the link down. For example, multiplier = 3 means the link is declared down if 3 consecutive packets are missed.

Inbound Routing Type

Specifies what kind of route information you receive from the transit provider:

• Full Route: You receive the entire global BGP routing table (all internet routes). Offers full control over path selection but requires more memory and CPU.

• Default Route: You receive a single default route (0.0.0.0/0) that sends all non-local traffic to the provider. Simpler and less resource-intensive.

• Full Route + Default Route: You get the full routing table and a default route. Allows flexible fallback if specific routes are withdrawn or filtered.