ip MTU

• To set the maximum transmission unit (MTU) size of IP packets that are sent on an interface, use the ip mtu command in interface configuration mode.
•  To restore the default MTU size, use the no form of this command.
• 
  

ip mtu bytes

no ip mtu

• 
  
• The default MTU value depends on the interface medium. The following table lists the default MTU values 
• according to media types.
• Default Media MTU Values
• Ethernet: 1500
• Serial: 1500
• Token Ring: 4464
• ATM: 4470
• If an IP packet exceeds the MTU size that is set for the interface, Cisco software will fragment the IP packet.
• for more info se doc

Question:

Normalize the packet flows for the link by adjusting the MTU so that each IP packet takes no more than 10ms to be sent. ?
ANS: 

• find the MTU value,
• this mtu vlaue is equal to the ip packet size send in 10ms

bandwidth = 128kbps

128kbps = 128 kilo bits per second

              

second1000milliseconds(ms)

• from above simple calculations for every one millisecond 16bytes wille be send
• for 10 milliseconds is 10times of 16bytes i.e 160bytes
• then required mtu value is 160bytes