An extension to the IETF BGP4 MIB module defined in
RFC 1657.

Following is the terminology associated with Border
Gateway Protocol(BGP).

UPDATE message
    UPDATE messages are used to transfer routing 
    information between BGP peers. An UPDATE message 
    is used to advertise a single feasible route to a
    peer, or to withdraw multiple unfeasible routes 
    from service.                 

Adj-RIBs-In 
   The Adj-RIBs-In store routing information that has
   been learned from inbound UPDATE messages. Their 
   contents represent routes that are available as an 
   input to the Decision Process.

Loc-RIB(BGP table) 
   The Loc-RIB contains the local routing information
   that the BGP speaker has selected by applying its 
   local policies to the routing information contained 
   in its Adj-RIBs-In.

Adj-RIBs-Out 
   The Adj-RIBs-Out store the information that the
   local BGP speaker has selected for advertisement to 
   its peers. The routing information stored in the 
   Adj-RIBs-Out will be carried in the local BGP 
   speaker's UPDATE messages and advertised to its
   peers.

Path Attributes
   A variable length sequence of path attributes is 
   present in every UPDATE. Each path attribute is a 
   triple  of variable length. 

Network Layer Reachability Information(NLRI)
   A variable length field present in UPDATE messages
   which contains a list of Network Layer address 
   prefixes. 

Address Family Identifier(AFI) 
   Primary identifier to indicate the type of the 
   Network Layer Reachability Information(NLRI) being 
   carried.

Subsequent Address Family Identifier(SAFI) 
   Secondary identifier to indicate the type of the 
   Network Layer Reachability Information(NLRI) being 
   carried.