3com MSR 20-20 참조 매뉴얼

length: The maximum number of consecutive information frames the router can 
send before receiving an acknowledgment from the peer, in the range of 1 to 127.

Use the llc2 receive-window command to configure the maximum number of 
consecutive information frames the router can send before receiving an 
acknowledgment from the peer.

Use the undo llc2 receive-window command to restore the default setting.

By default, the maximum number of consecutive information frames the router 
can send before receiving an acknowledgment from the peer is 7.

# Set the maximum number of consecutive information frames the router can 
send before receiving an acknowledgment from the peer to 10 on Ethernet 1/0.

<Sysname> system-view

[Sysname] interface ethernet 1/0

[Sysname-Ethernet1/0] llc2 receive-window 10 

llc2 timer ack mseconds

Ethernet interface view

mseconds: LLC2 acknowledgment waiting time in milliseconds. The effective 
range is 1 to 60,000.

Use the llc2 timer ack command to configure the LLC2 acknowledgment 
waiting time, namely the maximum length of time the router waits for an 
acknowledgment from the peer after sending an LLC2 frame.

Use the undo llc2 timer ack command to restore the default setting.

By default, the LLC2 acknowledgment waiting time is 200 milliseconds.

# Set the LLC2 acknowledgment waiting time to 10 milliseconds on Ethernet 1/0.

<Sysname> system-view

[Sysname] interface ethernet 1/0

[Sysname-Ethernet1/0] llc2 timer ack 10 

llc2 timer ack-delay mseconds