Topology

Technically, Ansp Network works as a NAP (Network Access Point) or Internet Exchange Point (PTT), with some changes. So, Ansp, together with NAP do Brasil, established PTTA (Exchange Point of Academic Traffic) rules, name given to VLAN where Ansp participants Exchange traffic between them and have right to access transit offered by NAP do Brasil commercial and organizational clients, beyond Internet providers offered by Ansp.

Hardware and Connections

PTTA consists basically in an Ethernet switch, called peering switch, with VLAN (Virtual LAN) resources, with enough number of doors to meet all participants, a BGP route server, whose characteristics and functions are described below, and the routers from each participant institution, called peers. Each institution shall hire or establish a link with peering switch and may choose to install a router with at least one WAN door and a LAN door.

Traffic management

The traffic exchange between PTTA participants is private and mediated by BGP route server. This can be a router or a server possessing a software that emulates a router compatible with BGP-4. Each of the peers receive an Autonomous System Number (ASN) private, if doesn’t have a public ASN or doesn’t want to use it. All the peers must pass their respective prefixes (IP address blocks) in its ASN scope for the route server, in charge of redistributing them to others (ilustration below). This is a practice recommended by ITU [Southwood, 2005, p.30 item 25].

Internet access

Ansp project undertakes to provide access to Internet Commodity and Internet 2 for all its integrants.