The following cards, modules, and platforms support multilink bundles:
T1/E1 ports on the 7705 SAR-A
T1/E1 ports on the 7705 SAR-M
T1/E1 ports on the 7705 SAR-X
The following must have all member links of an MLPPP bundle configured on the same card or module:
16-port T1/E1 ASAP Adapter card
32-port T1/E1 ASAP Adapter card
T1/E1 ports on the 4-port T1/E1 and RS-232 Combination module (on 7705 SAR-H)
The following must have all member links of an MLPPP bundle configured on the same card or module, and on the same port:
2-port OC3/STM1 Channelized Adapter card
4-port OC3/STM1 / 1-port OC12/STM4 Adapter card
Multilink bundling is based on a link control protocol (LCP) option negotiation that allows a system to indicate to its peer that it is capable of combining multiple physical links into a bundle. Each bundle represents a single connection between two routers. The bundles aggregate channelized ports to define the bandwidth between the routers over the DS1 links.
Multilink bundling operations are modeled after a virtual PPP link-layer entity where packets received over different physical link-layer entities are identified as belonging to a separate PPP network protocol (the Multilink Protocol, or MP) and recombined and sequenced according to information present in a multilink fragmentation header. All packets received over links identified as belonging to the multilink arrangement are presented to the same network-layer protocol processing machine, whether they have multilink headers or not.
When you configure multilink bundles, consider the following guidelines.
A multilink bundle configuration should include at least 2 ports.
Multilink bundles can only be aggregated on a single adapter card.
All member links of an MLPPP group must be of the same type (either E1 or Ds1).
When you configure a channel group on the network side with ppp-auto encapsulation, the system automatically allocates all timeslots to the channel group.
When you configure a channel group on the access side with IPCP encapsulation, the system does not automatically allocate all timeslots to the channel group. To use the port or channel group as a member in an MLPPP or MC-MLPPP, you must manually allocate all the timeslots to the channel group before adding it to the bundle.