H3C MSR 20-20 Command Reference Manual page 303

Parameter
Description
Example
mtu
Syntax
View
Parameter
Description
vt-number: Number of the virtual template (VT) interface corresponding to a
PPPoA map.
Use the command to create a PPPoA map on the PVC.
map ppp
Use the
undo map ppp
By default, no mapping is configured.
Before this command is used, the VT must have already been created.
The following example demonstrates a complete process of PPPoA configuration.
# Create a VT interface numbered 10, and assign it an IP address.
<Sysname> system-view
[Sysname] interface virtual-template 10
[Sysname-Virtual-Template10] ip address 202.38.160.1 255.255.255.0
[Sysname-Virtual-Template10] quit
# Create PVC 1/101 on interface Atm1/0.
[Sysname] interface atm 1/0
[Sysname-Atm1/0] pvc 1/101
# Create a PPPoA map using the VT interface created.
[Sysname-atm-pvc-Atm1/0-1/101] map ppp virtual-template 10
mtu mtu-number
undo mtu
Interface view
mtu-number: MTU size on ATM interface, in range of 128 to 2000 bytes.
Use the mtu command to set the size of maximum transmission unit (MTU) on
ATM interface.
Use the command to restore the default.
undo mtu
By default, the MTU of an ATM interface is 1,500 bytes.
The MTU only influences the packet assembly and disassembly at IP layer at the
ATM interface. Due to the limit of QoS queue length (for example, the default
length of the FIFO queue is 75), MTU which is too small may cause numerous
fragments and thus be dropped by the QoS queue. In this case, the length of the
QoS queue can be increased appropriately. The default queue dispatching
command to delete the map.
303