ZyXEL Communications P-660HN-T1H User Manual

Chapter 6 WAN Setup

P-660HN-T1H User’s Guide

In this case the IP address assignment must be static.

In this case you can have either a static or dynamic IP. For a static IP you must fill 
in all the IP Address and Gateway IP Address fields as supplied by your ISP. 
However for a dynamic IP, the ZyXEL Device acts as a DHCP client on the WAN 
port and so the IP Address and Gateway IP Address fields are not applicable 
(N/A) as the DHCP server assigns them to the ZyXEL Device.

A nailed-up connection is a dial-up line where the connection is always up 
regardless of traffic demand. The ZyXEL Device does two things when you specify 
a nailed-up connection. The first is that idle timeout is disabled. The second is that 
the ZyXEL Device will try to bring up the connection when turned on and 
whenever the connection is down. A nailed-up connection can be very expensive 
for obvious reasons. 

Do not specify a nailed-up connection unless your telephone company offers flat-
rate service or you need a constant connection and the cost is of no concern.

NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP 
address of a host in a packet, for example, the source address of an outgoing 
packet, used within one network to a different IP address known within another 
network.

Traffic Shaping is an agreement between the carrier and the subscriber to regulate 
the average rate and fluctuations of data transmission over an ATM network. This 
agreement helps eliminate congestion, which is important for transmission of real 
time data such as audio and video connections.

Peak Cell Rate (PCR) is the maximum rate at which the sender can send cells. This 
parameter may be lower (but not higher) than the maximum line speed. 1 ATM 
cell is 53 bytes (424 bits), so a maximum speed of 832Kbps gives a maximum 
PCR of 1962 cells/sec. This rate is not guaranteed because it is dependent on the 
line speed.