Alcatel Carrier Internetworking Solutions Switch/Router 사용자 설명서

Page 29-16

An InARP message is sent between the two routers indicating their IP addresses and associ-
ated VC. Once they know each other’s IP address and the 

DLCI

 of the VC on each end of the 

link (the same VC may have a different 

DLCIs

 on each end), then they can begin normal rout-

ing of RIP frames, etc.

The IP protocol must account for the Frame Relay network in making routing decisions. After 
all, the 

WAN

 network is more than just a single cable, or even several cables, attaching two 

routers. The solution is to assign the Frame Relay network a unique IP subnet.

In the configuration shown above, one virtual circuit connects the 

WSX

 router on IP Subnet 

1.1.1.x and the other router on IP Subnet 3.3.3.x. The Frame Relay network, for routing 
purposes, is considered to be IP Subnet 2.2.2.x. Routing decisions are straightforward in this 
setup. But if another Router and another IP Subnet were added, a special routing technique 
must be devised.

Frame Relay network consid-
ered a unique IP Subnet by IP.

Virtual circuit connects
two 

WAN

 Routers.