Seonglae ChoPath vector is exchanged
Two BGP peers (routers) exchange BGP messages over semi-permanent TCP connection.
Advertising paths to different destination network prefixes. So BGP is path vector protocol. BGP’s main purpose is Policy, not a speed. We chose policy instead of speed because we can’t estimate and control another AS’s network. This is fundamental difference between OSPF(shortest path) like Intra-AS.