Voice Over IP 3
T0008-48/B Revision 5.2
About Voice over IP (VoIP)
Network Topology
Introduction This section describes a typical network topology for the application of VoIP.
Network Topology Figure 2 illustrates a typical network topology for voice traffic.
Figure 2. Example Network Topology
Node Conventions The node conventions described below refer to Figure 2 and are used throughout this
document.
IP Network
PB S200
Source IP Node
PB S200 Destination
IP Node
PBX
Voice Device
Voice
Network
Voice Device
Voice
Network
Convention Description
Voice Device or Network The voice device or network sends voice to
the voice port on the source IP node.
Source IP Node The source IP node is a PathBuilder S200
series switch that
• connects directly to the voice device.
• connects directly to the IP network.
• connect directly to a frame relay network
supporting voice.
• encapsulates voice received from the
voice device or network using 3Com’s
SoTCP protocol.
• initiates calls to the peer, the destination
IP node.
Destination IP Node The destination IP node is a PathBuilder
S200 series switch that receives SoTCP
packets sent from the source IP node over the
IP network. The destination IP node
un-encapsulates SoTCP packets and sends
voice traffic to the PBX.The PBX may also
connect to a frame relay network supporting
voice.
PBX The PBX connects to the destination IP node
and receives voice traffic from it.
