Which two statements are true about MLP interleaving? (Choose two.)
A.
It fragments and encapsulates all packets in a fragmentation header.
B.
Packets smaller than the fragmentation size are interleaved between the fragments of the
larger packets.
C.
Packets larger than the fragmentation size are always fragmented, and cannot be interleaved,
even if the traffic is voice traffic.
D.
It fragments and encapsulates packets that are longer than a configured size, but does not
encapsulate smaller packets inside a fragmentation header.
Explanation:
Previous implementations of Cisco IOS Multilink PPP (MLP) include support for Link
Fragmentation Interleaving (LFI). This feature allows the delivery of delay-sensitive packets, such
as the packets of a Voice call, to be expedited by omitting the PPP Multilink Protocol header and
sending the packets as raw PPP packets in between the fragments of larger data packets. This
feature works well on bundles consisting of a single link. However, when the bundle contains
multiple links there is no way to keep the interleaved packets in sequence with respect to each
other.
Interleaving on MLP allows large packets to be multilink encapsulated and fragmented into a small
enough size to satisfy the delay requirements of real-time traffic; small real-time packets are not
multilink encapsulated and are transmitted between fragments of the large packets.
Note: The following URL from Cisco’s website explains this feature:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt6/qcflfi.htm
#wp1000907
“(Optional) Configures a maximum fragment delay. If, for example, you want a voice stream to
have a maximum bound on delay of 20 milliseconds (ms) and you specify 20 ms using this
command, MLP will choose a fragment size based on the configured value.”
Packets are fragmented when they exceed the configured maximum delay.