Monitor one 

A comprehensive, all-in-one and graphical all-in-one network monitoring software for network uptime and health monitoring. Provides sophisticated features for real-time monitoring and graphing using SNMP, trending, logging and long term analysis.
network monitoring software network management tool snmp manager snmp trap snmp software snmp network monitoring performance bandwidth utilization uptime rmon snmp ping

PortMarshaller 

PortMarshaller is a software-based TCP/IP port forwarder. The software accepts connections on a particular TCP port, and establishes connections to a different TCP port to fulfill requests.
tcp/ip port forwarder