A request is sent from a first base station to a second base station for a transport layer address assigned to the second base station that is suitable for establishing a connection between the first base station and the second base station. The second base station determines whether to include an outer address assigned to the second base station in a response to the request. If that is the case, the second base station sends the response to the first base station that includes a tunnel inner address assigned by a security gateway to the second base station and the outer address. The first base station determines whether the outer address is included in the response. If that is case, the outer address is used to establish the connection between the first base station and the second base station without using the security gateway.