Paradyne JetFusion 2008, User Manual

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Voice and Data Applications
Set the PCR for the Voice PVC to the maximum for the link’s transmission
rate and set the PCR for the data PVC to zero. This allows the IAD to
dynamically allocate the bandwidth with Voice having the highest priority.
For example, on an G.SHDSL link running at 512 kbps, set the PCR at 1208
for the Voice PVC, and set the PCR for Data to 0 (zero).
Network Address Translation (NAT)
In an IP network, all devices must have unique IP addresses. NAT allows
multiple devices on the LAN port of an IAD to share Internet access via the
IP address of the WAN port of the IAD. With this configuration, the LAN
port of the IAD and all LAN devices should use one of the private IP address
ranges as defined in Section 3, Page 4 of RFC 1918: 10.0.0.0 through
10.255.255.255, 172.16.0.0 through 172.31.255.255, or 192.168.0.0 through
192.168.255.255.
Accessing the Internet from the LAN
When you want to access the Internet from the LAN, but do not want to
access any local LAN devices from the Internet, enable NAT translation on
the WAN port that is connected to the Internet Service Provider (ISP). If two
ATM PVCs are defined and one of these is connected to a voice gateway, the
PVC connected to the ISP should have NAT enabled.
Configuring NAT Port Range
When you access the internet from the LAN, the request uses the next unused
port number in the configured NAT port range. For most applications, the
default range of 30000 through 65535 will work, as these port numbers are
not commonly used. If any port numbers in this range are used (i.e.,
multiplayer Internet games), the range must be adjusted. The number of
concurrent requests through NAT is limited by the size of the range. For
current port number assignments, please refer to http://www.iana.org/
assignments/port-numbers.
Configuring NAT TCP Timeout
When a TCP connection is made through NAT, a context block is allocated
from the IAD’s memory. This context block is freed when either the TERM
bit is seen in the TCP header, or when the timeout period has been exceeded
with no data. In most applications, the default value of 5 min (300 s) will be
sufficient. If the application features a large number of aborted TCP
connections, this value may need to be lowered. If the application features
connections with longer idle times, this value may need to be increased.