Juniper JUNOSE 11.1.X - LINK LAYER CONFIGURATION 4-7-2010 Configuration Manual page 145

frame-relay interface-dlci ietf
Use to assign a text description or an alias to a Frame Relay interface or
subinterface.
You can use this command to help you identify the interface and keep track of
interface connections.
The description or alias can be a maximum of 80 characters.
Use "show frame-relay interface" on page 124 or "show frame-relay subinterface"
on page 130 to display the text description.
Examples
host1(config-if)#frame-relay description boston01
host1(config-subif)#frame-relay description toronto011
Use the no version to remove the text description or alias.
See frame-relay description.
Use to configure a Frame Relay permanent virtual circuit (PVC) over a
subinterface.
The ietf keyword is mandatory and indicates RFC 2427 encapsulation.
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.
Chapter 2: Configuring Frame Relay
Configuring Frame Relay
113