3com 3031 Instruccion De Instalación
24
F
RAME
R
ELAY
C
ONFIGURATION
Introduction to the
Frame Relay Protocol
Frame Relay Protocol
Frame-Relay protocol is a simplified X.25 WAN protocol. A frame relay network
provides capacity of data communication between user equipment (such as
routers and hosts), also called data terminal equipment (DTE). The equipment that
provides access for DTE is data circuit-terminating equipment (DCE).A frame relay
network can be a public network, a private enterprise network, or a network
formed by direct connection between data equipment.
provides capacity of data communication between user equipment (such as
routers and hosts), also called data terminal equipment (DTE). The equipment that
provides access for DTE is data circuit-terminating equipment (DCE).A frame relay
network can be a public network, a private enterprise network, or a network
formed by direct connection between data equipment.
The frame relay protocol is a statistical multiplexing protocol, providing multiple
virtual circuits on a single physical transmission line. Each virtual circuit is identified
by a DLCI (Data Link Connection Identifier), which is valid only on the local
interface and the corresponding opposite interface. This means that in the same
frame relay network, the same DLCI on different physical interfaces does not
indicate the same virtual connection. An FR network user interface can supports
up to 1024 VCs. The users are allowed to assign them with the DLCIs in the range
of 16 to 1007. As a frame relay virtual circuit is connection oriented, different
local DLCIs are connected to different opposite equipment. Therefore, the local
DLCI can be considered as the "frame relay address" of the opposite equipment.
virtual circuits on a single physical transmission line. Each virtual circuit is identified
by a DLCI (Data Link Connection Identifier), which is valid only on the local
interface and the corresponding opposite interface. This means that in the same
frame relay network, the same DLCI on different physical interfaces does not
indicate the same virtual connection. An FR network user interface can supports
up to 1024 VCs. The users are allowed to assign them with the DLCIs in the range
of 16 to 1007. As a frame relay virtual circuit is connection oriented, different
local DLCIs are connected to different opposite equipment. Therefore, the local
DLCI can be considered as the "frame relay address" of the opposite equipment.
s protocol address with its frame relay address (local DLCI), so that the upper layer
protocol can locate the opposite equipment by using its protocol address. Frame
Relay is mainly used to carry IP protocol. When IP packet is sent, it can only obtain
the next hop address according to the routing table. Therefore, the relevant DLCI
must be determined by this address before sending IP packet. This process can be
performed by searching for the frame relay address mapping table, because the
mapping relation between the opposite IP address and the next hop DLCI is stored
in the address mapping table. The address mapping table can be manually
configured, or maintained dynamically by the Inverse ARP protocol. As shown in
the following figure, LANs can be interconnected through frame relay network.
protocol can locate the opposite equipment by using its protocol address. Frame
Relay is mainly used to carry IP protocol. When IP packet is sent, it can only obtain
the next hop address according to the routing table. Therefore, the relevant DLCI
must be determined by this address before sending IP packet. This process can be
performed by searching for the frame relay address mapping table, because the
mapping relation between the opposite IP address and the next hop DLCI is stored
in the address mapping table. The address mapping table can be manually
configured, or maintained dynamically by the Inverse ARP protocol. As shown in
the following figure, LANs can be interconnected through frame relay network.