ZyXEL Communications AMG1302-T10A, User Manual

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Chapter 6 WAN Setup
AMG1302-T10A User’s Guide
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either a dynamic or static IP. However the encapsulation method assigned influences your choices
for IP address and ENET ENCAP gateway.
IP Assignment with PPPoA or PPPoE Encapsulation
If you have a dynamic IP, then the
IP Address
and
Gateway IP Address
fields are not applicable
(N/A). If you have a static IP, then you need to fill in the
IP Address
field, the Subnet mask and
the
Gateway IP Address
field.
IP Assignment with RFC 1483 Encapsulation
In this case the IP address assignment must be static.
IP Assignment with ENET ENCAP Encapsulation
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
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 Device.
6.4.5 Nailed-Up Connection (PPP)
A nailed-up connection is a dial-up line where the connection is always up regardless of traffic
demand. The Device does two things when you specify a nailed-up connection. The first is that idle
timeout is disabled. The second is that the 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.
6.4.6 NAT
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.
6.5 Traffic Shaping
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.