3Com 3C840 User Manual page 159

Symptom Possible Cause
My video application Some video applications
does not run when using UDP streaming
Port Address have two connections,
Translation (PAT) is a TCP connection for
enabled. control and a UDP
stream for data. The
TCP connection is
initiated from the
privately addressed
workstation but the
video stream may be
initiated from the
remote server. Because
a mapping does not
already exist for the
UDP data stream, the
data can not be
mapped to a private
address unless a static
PAT port has been
defined or the PAT
default address is
configured.
IP Network Connection Problems 13-11
Corrective Action
First verify the possible cause stated
above is actually the problem. Set
the Remote Site's PAT default
address to your workstation's LAN
address, then try to run your video
application again. If it works, check
to see if your video application
allows you to specify a static UDP
port. Microsoft NetShow allows
you to configure a static UDP port
in the Properties > Advanced
screen. After setting a static port
for the video application, you must
add a corresponding static port
entry on the OfficeConnect
Remote 840. Set your Remote Site
default PAT address to 0.0.0.0
before you try the static port.
If you cannot setup a static port on
the Video application, check to see
if the Video application allows you
to specify TCP rather than UDP.
TCP streams are typically initiated
from the private side.
If you still are unsuccessful, the
video application may be
embedding address and port
information within the data
portion of the frame. If this is the
case, consult your application
vendor for possible workarounds.