3com MSR 20-20 참조 매뉴얼

Use the undo frame-format command to restore the default, that is, CRC4 
ADM for ATM E1 interfaces and ESF ADM for ATM T1 interfaces.

ATM Direct Mapping (ADM) directly maps ATM cells transmitted over the E1/T1 
line into E1/T1 frames. This process is defined by ITU-T G.804 and ATM forum.

# Configure no-CRC4 ADM framing on ATM E1 interface 5/0.

<Sysname> system-view

[Sysname] interface atm 5/0

[Sysname-Atm5/0] frame-format no-crc4-adm 

frame-length { 32 | 64 | 128 | 256 }

IMA group interface view

32, 64, 128, 256: Specifies the number of ATM cells in an IMA frame.

Use the frame-length command to configure the number of ATM cells in an IMA 
frame.

Use the undo frame-length command to restore the default, that is, 128 ATM 
cells in an IMA frame.

# Set the number of ATM cells in an IMA frame to 64 on IMA group interface 1.

<Sysname> system-view

[Sysname] interface atm 5/0

[Sysname-Atm5/0] ima ima-group 1

[Sysname-Atm5/0] interface ima-group 5/1

[Sysname-Ima-group5/1] frame-length 64 

ima ima-group group-number

ATM E1/T1 interface view

group-number: IMA group number, in the range 1 to 8.

Use the ima ima-group command to add an ATM E1/T1 interface to an IMA 
group. If the specified IMA group does not exist, it is created first.