Juniper JUNOSE 11.1.X - LINK LAYER CONFIGURATION 4-7-2010 Configuration Manual page 154

JUNOSe 11.1.x Link Layer Configuration Guide
frame-relay interface-dlci ietf
interface serial
NOTE: See "Before You Configure Frame Relay" on page 110 for more information
about configuring the underlying physical interfaces.
122
End-to-End Fragmentation and Reassembly
Use to configure a Frame Relay 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 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 16 ietf
Use the no version to remove DLCI/PVC assignment.
See frame-relay interface-dlci ietf.
Use to configure a serial interface in the appropriate format by selecting a
previously configured physical interface on which you want to configure Frame
Relay. For example, for a channelized T3 interface use
slot/port:channel/subchannel.
Use to configure a Frame Relay subinterface in the appropriate format by selecting
a previously configured physical interface. For example, for a T3-Frame interface
use slot/port.subinterface; for a channelized T1/channelized E1 interface use
slot/port.channel-group.subinterface.