3Com PathBuilder S200 Series Manual page 11

Data Transfer The SoTCP protocol attaches the 3 or 4-byte header to the packet. The SoTCP
protocol then sends voice packets over the UDP channel.
Voice Over IP
T0008-48/B
Stage Packet Transferred
3 SoTCP Internal Call
Accept
4 ACP Call Accept
About Voice over IP (VoIP)
Description (continued)
Once the destination IP node receives the
ACP call accept from the remote voice
port, it sends a SoTCP Internal Call Accept
to the source IP node. The remote port's
UDP port number is included in this packet
to inform the other end of its UDP port
number. The connection between the nodes
is now established.
The source IP node sends an ACP Call
Accept to the voice port and the port may
begin to send voice packets to the
destination.
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Revision 5.2