notes: PPP Multilink PPP (MLP)

- MLP provides a method for spreading traffic across multiple physical WAN links while providing packet fragmentation and reassembly, proper sequencing, multivendor interoperability, and load balancing on inbound and outbound traffic.
- MLP fragmentation sends the fragments simultaneously over multiple point-to-point links to
the same remote address.
- MLP can measure the load on just inbound traffic, or on just outbound traffic, but not on the combined load of both inbound and outbound traffic.

CONFIG-SET: MLP - Configuring a Multilink PPP Bundle
+-----------------------------------------------------
interface s0/0
no ip add
encapsulation ppp
ppp multilink
multilink-group 2
!
interface s0/1
no ip add
encapsulation ppp
ppp multilink - Enables MLP on S0/1
multilink-group 2
!
interface multilink2
ip address 192.168.0.1 255.255.255.0
ppp multilink
multilink-group 2


LFI (Link Fragmentation and Interleaving)

- 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.

- The interleaving feature also provides a special transmit queue for the smaller, delay-sensitive packets, enabling them to be transmitted earlier than other flows.

- Interleaving applies only to interfaces that can configure a multilink bundle interface.

- WFQ on MLP works at the packet level, not at the level of multilink fragments.
- Maximum fragment delay: If one specifies 20 ms delay, MLP will choose a fragment size based on the configured value.


MCMP (Multi-class Multilink PPP)

- 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.

MRRU Negotiation

- The PPP/MLP MRRU negotiation configuration feature allows a router to send and receive frames over MLP bundles that are larger than the default Maximum Receive Reconstructed Unit (MRRU) limit of 1524 bytes.
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COMMANDS
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interface s0/1
ppp multilink - Enables MLP
multilink-group {no} - Specifies interface multilink group membership
ppp multilink interleave - Enables LFI, real-time packet interleaving
ppp multilink fragment-delay {ms} - (o) Configure a maximum fragment delay
ppp multilink multiclass - Enables MCMP on an interface
ppp multilink mrru [local | remote] {mrru-value}

- Configures the MRRU value negotiated on a MLP bundle
- [local] Configures the local MRRU value
- [remote] The min value to be accepted from the peer