The Network Swiftlet is the interface for SwiftMQ Swiftlets to the network. The standard version uses standard blocking I/O with 1 thread per connection, listening on the input stream. There is another version of the Network Swiftlet that supports the new java.nio APIs. That version provides true nonblocking I/O with only a few threads for hundreds of concurrent connections.
Both versions of the Network Swiftlet support reliable IP multicast through the Lightweight Reliable IP Multicast Protocol (LRMP). To use publish/subscribe over IP multicast, one has to install the Multicast Extension Swiftlet. LRMP has a profil with several configuration properties. SwiftMQ provides similar attributes which are mapped directly to LRMP. Read the following white paper for a detailed introduction into LRMP.
Zombi connections are those connections that are created but where no data is sent. Since the keepalive has not been started yet, these connection were never closed in the past. Zombi connections can occur if, for example, SwiftMQ is monitored by opening telnet connections on a JMS listener port and also by DoS attacks. To prevent that zombi connections brings the router down, attribute "zombi-connection-timeout" can be set to a millisecond value, e.g. 10000 (10 secs). The Network Swiftlet then starts a timer on each connect and disconnects the connection if the protocol has not been initiated when the timer fires.