
Chapter 7
Scenario 1: Residential user.
E-NIT-CTC-20041213-0013v0.5 89
When we click on the + next to the H323 expression we can see the definitions used 
for this expression.
Here we can see that the expression h323 is used for packets :
of the type TCP (proto=6) with destination port 1720.
of the type UDP (proto=17) with destination port 1720.
of the type TCP (proto=6) with destination port 1718.
of the type UDP (proto=17) with destination port 1718.
of the type TCP (proto=6) with destination port 1719.
of the type UDP (proto=17) with destination port 1719.
These six expressions define the protocol and ports used by H323.
Meaning that when TCP traffic on port 1720 is transmitted the SpeedTouch™ knows 
that this is H323 traffic. This also applies for UDP traffic on port 1720. By defining 
these expressions we help the SpeedTouch™ to determine the service used.
Again at the bottom of the page you can see the actual protocol instead of the 
number.
These are all parameters needed to enable classification for VoIP. The actual 
Quality of Service is defined later on.