feat(interlink): start concepts

Author: RoRoJ

network/interlink/concepts.mdx

@@ -0,0 +1,63 @@
+---
+meta:
+  title: InterLink - Concepts
+  description: Understand Scaleway InterLink terminology with our glossary of the core concepts underpinning this product. Learn about key features, architecture, and workflows.
+content:
+  h1: InterLink - Concepts
+  paragraph: Understand Scaleway InterLink terminology with our glossary of the core concepts underpinning this product. Learn about key features, architecture, and workflows.
+tags: interlink direct-connect dedicated connection
+dates:
+  creation: 2024-10-31
+  validation: 2024-10-31
+categories:
+  - networks
+---
+
+## Allowed routes list
+
+The default rule blocks any and all routes from being propagated over InterLink. Attaching an allowed routes list allows you to define the ranges of routes that should be whitelisted. When creating an allowed routes list, you specify one or many IP ranges representing the outgoing routes to announce from the Scaleway VPC, and one or many IP ranges representing the incoming route announcements to accept from the external infrastructure. 
+
+Each InterLink can have one allowed routes list attached to it, but a single allowed routes list can be attached to multiple InterLinks, if desired. When [route propagation](#route-propagation) is activated, the route ranges defined in the allowed routes list are whitelisted, and traffic can flow across the InterLink along these routes.
+
+You may also know allowed routes lists under the germs "routing policy", or "route filters".
+
+TODO diagram incoming/outgoing routes with examples? API naming
+
+## Bandwidth
+
+Every InterLink has a defined bandwidth, representing the maximum data transfer rate possible over the connection. Measured in megabits per second (Mbps) or gigabits per second (Gbps), it shows how much data can be transmitted over InterLink per second.
+
+## InterLink
+
+InterLink is Scaleway's product to let you create a secure, private connection between your external infrastructure, and your Scaleway VPC. This allows you to direct your traffic safely from your Scaleway infrastructure to your on-premises infrastructure, away from the public internet.
+
+Currently, InterLink is available in **hosted** version only. This means that you must choose a compatible [partner](#partner) to facilitate the physical connection between the external infrastructure and the Scaleway VPC. The physical connection may be shared between several clients, each allocated a specific amount of bandwidth for their InterLink.
+
+## Location
+
+A location, aka a **P**oint **o**f **P**resence (PoP), is a physical location where you can establish an InterLink connection between your on-premises infrastructure and the Scaleway network. Locations are facilitated by partners.
+
+## Pairing key
+
+A pairing key is a unique identifier used to establish and authenticate an InterLink connection. It is provided by Scaleway once an InterLink order is made. You must then share this key with your selected partner to facilitate the setup of the physical link. The pairing ley ensures that the correct endpoints are securely connected.
+
+## Partner
+
+A partner is a third party service provider that facilitates a hosted InterLink connection between a client's on-premises infrastructure, and their Scaleway infrastructure. Current partners include [Free Pro](https://pro.free.fr/), with more coming soon.
+
+Partners are generally companies specialized in data transit, with their own fibers at data connection points. To establish an InterLink connection via a partner, generally you must be client of that partner, e.g. with your infrastructure in their datacenter, or on your own premises using the partner as a network provider.
+
+## PoP
+
+See [Location](#location)
+
+## Region
+
+When creating an InterLink, you must specify a [region](/network/vpc/concepts/#region-and-availability-zone) for the resource. The region sets the scope for the Scaleway infrastructure that can be connected via the InterLink: it must correspond to the region of the VPC to attach to the InterLink.
+
+## Route propagation
+
+Route propagation can be activated or deactivated at any given time on an InterLink. When activated, the Scaleway VPC and external infrastructure dynamically exchange and update information about their routes. Route propagation must be activated to allow traffic to flow over the InterLink. When deactivated, all pre-learned/announced routes are removed from the VPC's route table, and traffic cannot flow. Note that even with route propagation activated, the default rule blocks all route announcements: you must use an [allowed routes list](#allowed-routes-list) to specify the route ranges to whitelist.
+
+
+