1. A computer implemented method comprising: in response to a first mobile network registration request from a mobile node, accessing a remote authentication facility to retrieve a security association for the mobile node for authenticating and providing a first network connectivity to the mobile node, wherein the security association is associated with a lifespan; inserting the security association in a local security association database to create a security association entry, wherein the security association entry includes the lifespan; receiving a second mobile network registration request from the mobile node after the first network connectivity has been terminated; and using the security association entry in the local security association database that corresponds to the mobile node to provide authentication of the mobile node without having to access the remote authentication facility again if the lifespan associated with the security association entry is valid.