The function of this layer is to establish an initial membership when a channel is created. It does so by either broadcasting3.10 a 'ping' message to a well-known IP address/port, or by contacting a Router daemon (see 3.8.1). Every member that receives this message (in the PING layer) responds with its own address and the address of the coordinator. Based on the replies, the newly created channel then tries to contact the coordinator to join the group, using a unicast message. If no members reply (after some timeout), the new channel will be the first member in the group. If this layer is not present, then the group membership layer (GMS) will unable to establish contact with existing members, which will result in a number of group members not 'finding' each other (singleton groups).