Cisco Systems 1000 Series Manual De Usuario

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Cisco ASR 1000 Series Aggregation Services Routers Software Configuration Guide
OL-16506-17
Chapter 8      Multilink PPP Support for the Cisco ASR 1000 Series Routers
  Information About Multilink PPP Support for Cisco ASR 1000 Series Routers
shape [average | peak] mean-rate [burst-size] [excess-burst-size] account {{{qinq | dot1q} {aal5 | 
aal3} {subscriber-encapsulation}} | {
user-defined offset [atm]}}
This command enables you to include the additional overhead added by a SPA using the user-defined 
option. For example, the Ethernet SPA adds an additional 24 bytes per packet so that a user-defined value 
of 24 covers Ethernet IPG (12) + Preamble (8) + CRC32 (4). Another interesting scenario is when 
deploying MLPoLNS in an ATM topology. The physical link between the LNS and the LAC is Ethernet, 
and the physical link between the LAC and the CPE is ATM. In such a scenario, you can add the atm 
keyword to include the ATM Cell overhead between the LAC and the CPE.
In Cisco IOS XE Release 3.6S, shaping and policing overhead accounting support was added for Serial 
Multilink PPP and Multilink PPP LFI.
For more information on shaping and policing, see the IOS XE Ethernet Overhead Accounting 
documentation
 at: 
Downstream Model-F Shaper on LNS
From Cisco IOS XE Release 3.7.1S, Model-F downstream shaping support for MLPoLNS is available 
to the Cisco ASR 1000 Series Aggregation Services Routers when these routers function as an LNS 
device.
Note
Model-F downstream shaping for MLPoLNS is not supported on the Cisco ASR 1002-X Router and the 
FP100 line card.
This section provides an example of a Model-F policy with a parent shaper policy attached to a VLAN 
interface on the LNS device. The VLAN interface is used for the L2TP tunnel between the LAC device 
and the LNS device. The following configuration example shows an aggregate shaper applied to a 
VLAN, which shapes all the MLP sessions going downstream to the LAC device:
policy-map lns_downstream_shaper_out
class class-default
shape average 5000000
interface GigabitEthernet0/1/0.2
encapsulation dot1Q 2
ip address 90.0.0.1 255.255.255.0
service-policy output lns_downstream_shaper_out
Note
Model-F QoS allows a parent shaper on the class-default class by using a flat policy. No additional QoS 
functionalities are supported in the Model-F policy.