An RSSI value of 0 means that the client is not currently receiving a signal.
If your client is successfully connected to one of these nodes, its assgined (dynamic) client ID, along with your IP address, port number, and RSSI information will be displayed under the node number associated with the client password you selected (or the default one, if you did not select one).
Once connected, you should be able (via the radio connected your client) to communicate with other connected clients and any Allstar users connected to the Allstar Node (2002). A common way of testing your client is to connect to an already functional Allstar node to Node 2002 or connect to Node 2002 via the WebTransceiver or Allstar Telephone Portal, and basically "talk to yourself" (or at least attempt to).
Node 2002 (Full Duplex Repeater with Tx CTCSS) contains the "radios" client, Node 1001 (Full Duplex Repeater without Tx CTCSS) contains the "rptnopl", "rptnopladpcm", and "rptnod" clients, Node 1002 (Simplex with Tx CTCSS) contains the "simp" and "simpnod" clients, and Node 1003 (Simplex without Tx CTCSS) contains the "simpnopl" and "cellnopl" clients. All 4 nodes are permanently "linked" together, and therefore only one node (2002) is a standard (publicly-accessible) Allstar Node.