Specifications

Multiprotocol Label Switching Commands
cell-packing
MP-19
Cisco IOS Multiprotocol Label Switching Command Reference
January 2010
Only cells from the same VC or VP can be packed into one MPLS or L2TPv3 packet. Cells from different
connections cannot be concatenated into the same packet.
When you change, enable, or disable the cell-packing attributes, the ATM VC or VP and the MPLS or
L2TPv3 emulated VC are reestablished.
If a provider edge (PE) router does not support cell packing, the PE router sends only one cell per MPLS
or
L2TPv3 packet.
The number of packed cells need not match between the PE routers. The two PE routers agree on the
lo
wer of the two values. For example, if PE1 is allowed to pack 10 cells per MPLS or L2TPv3 packet
and PE2 is allowed to pack 20 cells per MPLS or L2TPv3 packet, the two PE routers would agree to send
no more than 10 cells per packet.
If the number of cells packed by the peer PE router exceeds the limit, the packet is dropped.
If you issue the ce
ll-packing command without first specifying the atm mcpt-timers command, you get
the following error:
Please set mcpt values first
In order to support cell packing for static pseudowires, both PEs must run Cisco IOS
Release 12.2(1)SRE, and the maximum number of cells that can be packed must be set to the same value
o
n each.
Examples The following example shows cell packing enabled on an interface set up for VP mode. The ce
ll-packing
command specifies that ten ATM cells be packed into each MPLS packet. The command also specifies
that the second maximum cell-packing timeout (MCPT) timer be used.
Router> enable
Router# configu
re terminal
Router(config)# interface atm1/0
Router(config-if)# atm mcpt-timers 1000 800 500
Router(config-if)# atm pvp 100 l2transport
Router(config-if-atm-l2trans-pvp)# xconnect 10.0.0.1 234 encapsu
lation mpls
Router(config-if-atm-l2trans-pvp)# cell-packing 10 mcpt-timer 2
The following example configures ATM cell relay over MPLS with cell packing in VC class
configuration mode. The VC class is then applied to an interface.
Router> enable
Router# configu
re terminal
Router(config)# vc-class atm cellpacking
Router(config-vc-class)# encapsulation aal0
Router(config-vc-class)# cell-packing 10 mcpt-timer 1
Router(config-vc-class)# exit
Router(config)# interface atm1/0
Router(config-if)# atm mcpt-timers 100 200 250
Router(config-if)# class-int cellpacking
Router(config-if)# pvc 1/200 l2transport
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 enca
psulation mpls
The following example configures ATM AAL5 over L2TPv3 in VC class configuration mode. The VC
class is then applied to an interface.
Router(config)# vc-class atm aal5class
Router(config-vc-class)# encapsulation aal5
!
Router(config)# interface atm1/0
Router(config-if)# class-int aal5class
Router(config-if)# pvc 1/200 l2transport
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation l2tpv3