16-7
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 16 Fragmenting and Interleaving Real-Time and Nonreal-Time Packets
Link Fragmentation and Interleaving
ppp multilink fragment-delay Command
To specify a maximum size in units of time for packet fragments on a Multilink PPP (MLP) bundle, use
the
ppp multilink fragment-delay
command in interface configuration mode. To reset the maximum
delay to the default value, use the
no
form of the command. By default, if fragmentation is enabled, the
fragment delay is 30 milliseconds.
ppp multilink fragment-delay
delay-max
no
ppp multilink fragment-delay
delay-max
Syntax Description
ppp multilink fragment-delay Command History
Usage Guidelines for the ppp multilink fragment-delay Command
The
ppp multilink fragment-delay
command is useful when packets are interleaved and traffic
characteristics such as delay, jitter, and load balancing must be tightly controlled.
MLP chooses a fragment size on the basis of the maximum delay allowed. If real-time traffic requires a
certain maximum boundary on delay, using the
ppp multilink fragment-delay
command to set that
maximum time can ensure that a real-time packet gets interleaved within the fragments of a large packet.
By default, MLP has no fragment size constraint, but the maximum number of fragments is constrained
by the number of links. If interleaving is enabled, or if the bundle contains links that have differing
bandwidths, or if a fragment delay is explicitly configured with the
ppp multilink fragment-delay
command, then MLP uses a different fragmentation algorithm. In this mode, the number of fragments is
unconstrained, but the size of each fragment is limited to the fragment-delay value, or 30 milliseconds
if the fragment delay has not been configured.
The
ppp multilink fragment-delay
command is configured under the multilink interface. The value
assigned to the
delay-max
argument is scaled by the speed at which a link can convert the time value into
a byte value.
delay-max
Specifies the maximum amount of time, in milliseconds, that is required to
transmit a fragment. Valid values are from 1 to 1000 milliseconds.
Cisco IOS Release
Description
Release 12.0(23)SX
The
ppp multilink fragment-delay
command was introduced on the PRE1.
Release 12.2(16)BX
This command was introduced on the PRE2.
Release 12.2(28)SB
This command was integrated in Cisco IOS Release 12.2(28)SB for the
PRE2.
Release 12.2(31)SB2
This command was introduced on the PRE3.
