Juniper JUNOSE SOFTWARE 11.2.X - LINK LAYER CONFIGURATION GUIDE 7-7-2010 Configuration Manual page 143

frame-relay intf-type
frame-relay keepalive
Copyright © 2010, Juniper Networks, Inc.
Define a DLCI in the range 16–1007.
To configure a Frame Relay PVC, you must specify a DLCI.
Frame Relay service is offered in the form of PVCs. A PVC is a data-link connection
that is predefined on both ends of the connection. A network operator assigns the
endpoints of the circuit. Although the actual path taken through the network may vary
from time to time, the beginning and end of the circuit do not change. This type of
circuit behaves like a dedicated point-to-point circuit.
PVCs are identified by DLCIs. A DLCI is a 10-bit channel number that is attached to
data frames to tell a Frame Relay network how to route the data. Frame Relay is
statistically multiplexed, which means that only one frame can be transmitted at a
time, but many logical connections can coexist on a single physical line. The DLCI
allows the data to be logically tied to one of the connections, so that when the data
gets to the network, the network knows where to send it.
DLCIs on the same physical line must match. However, DLCIs have local significance;
that is, if the DLCIs are not on the same physical line, the end devices at two different
ends of a connection may use a different DLCI to refer to the same connection.
The router does not support switched virtual circuits (SVCs). An SVC is an any-to-any
connection that can be established or removed as needed. With SVCs, you initiate calls
using Frame Relay by requesting a destination address and assigning a DLCI, which is
established for the duration of the call.
Example
host1(config-subif)#frame-relay interface-dlci 17 ietf
Use the no version to remove DLCI/PVC assignment.
See frame-relay interface-dlci ietf.
Use to configure a Frame Relay interface circuit to operate as data communications
equipment (DCE), data terminal equipment (DTE), or NNI.
Frame Relay provides packet-switching data communications between user devices
and network equipment across the interface. User devices are referred to as DTE.
Network equipment that interfaces with a DTE is referred to as a DCE.
NNI provides a connection between two Frame Relay subnetworks.
If your router is connected to a Frame Relay switch, configure the interface as a DTE.
If your router is connected by a point-to-point line, configure one end as the DTE and
the other as the DCE.
Example
host1(config-if)#frame-relay intf-type dte
Use the no version to set the default of DTE.
See frame-relay intf-type.
Chapter 2: Configuring Frame Relay
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