Abstract: Devices, systems and methods are provided to support a party call with auto-joining function in a communication system for a distributed transport system that employs VoIP technology. A VoIP unit or end point acts as a conference bridge between an operator extension and other end points. A first end point makes a SIP call to the operator and multicasts a mix of its send audio and the received operator audio. Other end points first check for multicast traffic being received before making a SIP call to the operator and, if so, play out the received audio over its speaker and multicast its send audio. The end point initiating the call mixes this subsequent stream into a stream to the operator, effectively acting as the conference bridge to the operator. The other end points are responsible for mixing received multicast streams for their local speaker.

Abstract: Devices, systems and methods are provided to support a party call with auto-joining function in a communication system for a distributed transport system that employs VoIP technology. A VoIP unit or end point acts as a conference bridge between an operator extension and other end points. A first end point makes a SIP call to the operator and multicasts a mix of its send audio and the received operator audio. Other end points first check for multicast traffic being received before making a SIP call to the operator and, if so, play out the received audio over its speaker and multicast its send audio. The end point initiating the call mixes this subsequent stream into a stream to the operator, effectively acting as the conference bridge to the operator. The other end points are responsible for mixing received multicast streams for their local speaker.

Abstract: Devices, systems and methods are provided to support a party call with auto joining function in a communication system for a distributed transport system that employs VoIP technology. A VoIP unit or end point acts as a conference bridge between an operator extension and other end points. A first end point makes a SIP call to the operator and multicasts a mix of its send audio and the received operator audio. Other end points first check for multicast traffic being received before making a SIP call to the operator and, if so, play out the received audio over its speaker and multicast its send audio. The end point initiating the call mixes this subsequent stream into a stream to the operator, effectively acting as the conference bridge to the operator. The other end points are responsible for mixing received multicast streams for their local speaker.

Abstract: Devices, systems and methods are provided to support a party call with auto joining function in a communication system for a distributed transport system that employs VoIP technology. A VoIP unit or end point acts as a conference bridge between an operator extension and other end points. A first end point makes a SIP call to the operator and multicasts a mix of its send audio and the received operator audio. Other end points first check for multicast traffic being received before making a SIP call to the operator and, if so, play out the received audio over its speaker and multicast its send audio. The end point initiating the call mixes this subsequent stream into a stream to the operator, effectively acting as the conference bridge to the operator. The other end points are responsible for mixing received multicast streams for their local speaker.

Abstract: A stepladder includes first and second legs and a plurality of treads, wherein each first and second leg forms a separate channel for receiving the treads. A pad installed in the stepladder includes has a first portion residing under compression within the channel of the first leg between adjacent treads and a second portion residing outside of the channel of the first leg to provide the cushion for a worker when carrying the stepladder on his or her shoulder. The pad, suitably consisting of closed-cell foam, is held within the channel by frictional forces between the resilient pad, the first leg and the adjacent treads.