Juniper JUNOSE 11.2, Configuration Manual

Page: 151 / 772

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Use to configure a Frame Relay PVC over a subinterface.
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The ietf keyword is mandatory and indicates RFC 2427 encapsulation.
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Define a DLCI in the range 16–1007.
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To configure a Frame Relay PVC, you must specify a DLCI.
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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.
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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.
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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.
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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.
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Example
host1(config-subif)# frame-relay interface-dlci 16 ietf
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Use the no version to remove DLCI/PVC assignment.
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See frame-relay interface-dlci ietf.
interface serial
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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 .
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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 .
NOTE: See “Before You Configure Frame Relay” on page 108 for more information about
configuring the underlying physical interfaces.
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slot —Router chassis slot
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port —CT3, T3, or E3 module I/O port
119 Copyright © 2010, Juniper Networks, Inc.
Chapter 2: Configuring Frame Relay