Configuring the Point-to-Point Protocol (PPP)

Outgoing multilink options

The following options define how a bundle will handle outgoing multilink PPP connections:

Minimum number of active links

The minimum number of links that can remain in a bundle when bandwidth on demand has removed excess capacity. The value entered must be less than or equal to the number of links configured for the bundle.

Maximum number of active links

The maximum number of links that can be active in a multilink bundle. A number greater than 1 indicates the use of a multilink bundle. The value entered must be less than or equal to the number of links configured for the bundle.

Maximum received reconstructed unit size

The size of the maximum received reconstructed unit (MRRU) which is the maximum size in bytes of the information fields of reassembled packets. This must be defined if multilink connections are required.

NOTE: It is suggested that the value configured for the MRRU should be at least 6 bytes smaller than the maximum receive unit (MRU) that is set in the Link Control Protocol for the member links of the bundle.

Use short sequence numbers

Whether short sequence numbering is enabled. If enabled, PPP informs the peer that it wants to receive fragments with short, 12-bit sequence numbers rather than 24-bit sequence numbers.

Use endpoint discrimination

Whether endpoint discrimination is enabled. A system's endpoint discriminator identifies it to its peer when it tries to create a new multilink bundle or to add a link to an existing multilink bundle.

Packet size at which fragmentation stops

The minimum fragmentation size in bytes for a link. Packets with a size less than this will not be fragmented before being sent.

Maximum number of pending fragments

The maximum number of fragments that may be queued for reassembly per active (open to traffic) link in a bundle.

Inhibit control packet encapsulation

Whether Control Protocol packets are encapsulated within the multilink header. Set this to Yes for a multilink bundle to allow PPP in UnixWare^® 7 to interoperate with other PPP implementations that cannot interpret encapsulated Control Protocol packets.

NOTE: The preferred MRRU, short sequence numbering and endpoint discrimination characteristics of incoming connections must be set in the global bundle. These values are applied to all incoming connections because PPP must negotiate the multilink characteristics of the connection before it can associate the caller with a bundle.

WARNING: You should normally adjust only the maximum and minimum number of links to be used in a multilink bundle. Only change the other settings if you fully understand multilink PPP, or if the site at the remote side of the link provides you with values that are more suitable for the implementation of multilink PPP that they are using.

Refer to RFC 1990 for more information about multilink PPP.