Specifications

mpls ldp atm control-mode
MP-205
Cisco IOS Multiprotocol Label Switching Command Reference
January 2010
Usage Guidelines Use of ordered control mode by an ATM device acting as a transit LSR in an ATM cloud ensures that the
device will receive labeled packets to forward only after it has learned the outgoing labels required by
MPLS to forward the packets. Ordered control mode relieves the device of the burden of reassembling
cells into packets that must be forwarded by means of the normal (non-MPLS) packet forwarding or
discard mechanisms.
Use of independent control mode on ATM transit LSRs might slightly reduce the time an ATM edge
r
outer must wait to use an ATM label switched path (LSP) it has initiated. Independent control mode
eliminates the need for the edge router to wait for the Label Request/Label Mapping signaling to traverse
the ATM cloud from edge router ingress to egress and back before it can send packets into the LSP.
However, there is a risk that an ATM transit device might receive labeled packets before it has learned
the outgoing labels required for MPLS forwarding, thus forcing the transit device to reassemble the cells
into a packet that it is likely to discard.
Examples In the following example, the mode for handling LDP Label Request messages is set to “independent”
fo
r the platform:
Router# mpls ldp atm control-mode independent
12.2(28)SB This command was integrated into Cisco IOS Release 12.2(28)SB and
implemented on the Cisco 10000-PRE2 router.
12.4(20)T This command was removed.
Release Modification