ADTRAN Express 4110, User Manual

Page: 44 / 205

Chapter 1. Understanding ISDN and the Express 4110/4120
1-14 Express 4110/4120 User Manual 61200176L3-1
Network Address Translation Mode
NAT is a special mode of operation in which the Express 4110/4120
obtains a dynamically assigned IP address from the peer router (typically
an Internet Service Provider). This allows a network of computers to ben-
efit from Ethernet to ISDN speeds while still appearing to the Internet Ser-
vice Provider (or central site router) as a single IP address, which is
typical of PC based serial dial-up solutions.
A call is initiated to the ISP using the Dial menu or demand for a Connec-
tion List profile that has the IP parameter NAT set to Yes. The network
computer’s IP stack may use DHCP to request an IP address, default gate-
way address, and domain name server addresses from the Express 4110/
4120.
Front Panel
Figure 1-11 on page 1-14 shows the front panel of the Express 4110. Figure
1-12 on page 1-15 shows the front panel of the Express 4120. The indica-
tors are divided into LAN functions, WAN functions, and Test functions.
Figure 1-11. Express 4110 LEDs
Express 4110 LAN Indicators
TX/RX Flashes green when transmitting data onto the 10BaseT
connector.
Flashes yellow when receiving data from the 10BaseT
connector.
LI Link integrity. Illuminates when there is a good connection between
the Express 4110 and a NIC card.
Express 4110