Cisco's Netflow software provides the capability to collect the source and destination network prefixes of the traffic flows that pass through routers in the network.  However, knowing the source and destination network prefixes of the traffic flows in a data network is typically insufficient for traffic analysis and network modeling purposes. 
To adequately analyze and model traffic traversing a data network, it is important to be able to determine the autonomous system (AS) path from the source network to the destination network, and the entry and exit routers within a data network.  When autonomous systems use Border Gateway Protocols (BGPs) to exchange routing information, the entry and exit routers within a data network are equivalent to knowing the BGP next hop routers for the source and destination network prefixes, respectively.  Therefore, one can look up the entry and exit routers from the BGP routing table using the source and destination network prefixes, respectively. 
However, depending on the routing architecture for a particular data network, not all network prefixes may be in the BGP routing table, and therefore, it may not be possible to determine the entry and/or exit routers using only the BGP routing table. 
Therefore, there exists a need for a system and method that facilitate the analysis of a communications network by allowing for identification of the entry and exit routers for traffic flowing through a data network.