The paper introduces the organization concept of silaturahmi that widely used as an important concept to maintain a lot of community structures in Indonesia. One of the organization is alumni forum where alumni gathers and establishes an institutional organization. The concept of silaturahmi is demonstrated to build a network among alumni that has been spread world-wide by observing the clustered gathered in social clusters. The paper reports the small world topology emerged and discusses some interesting conjectures regarding to social institutions that is made upon the concept of silaturahmi
