Multichassis Multilink PPP Overview Prior to Release 11.2, Cisco IOS supported Multilink PPP (MLP). Beginning with Release 11.2, Cisco IOS software also supports Multichassis Multilink PPP (MMP).
Multilink PPP provides the capability of splitting and recombining packets to a single end-system across a logical pipe (also called a bundle) formed by multiple links. Multilink PPP provides bandwidth on demand and reduces transmission latency across WAN links. MMP, however, provides the additional capability for links to terminate at multiple routers with different remote addresses. MMP can also handle both analog and digital traffic. This feature is intended for situations with large pools of dial-in users, where a single chassis cannot provide enough dial ports. This feature allows companies to provide a single dialup number to its users and to apply the same solution to analog and digital calls. This feature allows internet service providers (ISPs), for example, to allocate a single ISDN rotary number to several ISDN PRIs across several routers. This capability allows for easy expansion and scalability, and for assured fault tolerance and redundancy. MMP allows network access servers to be stacked together and appear as a single network access server chassis so that if one network access server fails, another network access server in the stack can accept calls. With large-scale dial-out, these features are available for both outgoing and incoming calls. Stack Groups Routers or access servers are configured to belong to groups of peers, called stack groups. All members of the stack group are peers; stack groups do not need a permanent lead router. Any stack group member can answer calls coming from a single access number, which is usually an ISDN PRI hunt group. Calls can come in from remote user devices, such as routers, modems, ISDN terminal adapters, or PC cards. Once a connection is established with one member of a stack group, that member owns the call. If a second call comes in from the same client and a different router answers the call, the router establishes a tunnel and forwards all packets belonging to the call to the router that owns the call. Establishing a tunnel and forwarding calls through it to the router that owns the call is sometimes called projecting the PPP link to the call master. If a more powerful router is available, it can be configured as a member of the stack group and the other stack group members can establish tunnels and forward all calls to it. In such a case, the other stack group members are just answering calls and forwarding traffic to the more powerful offload router. -------------------------------------------------------------------------------- Note High-latency WAN lines between stack group members can make stack group operation inefficient. -------------------------------------------------------------------------------- Michael Williams wrote: >Hey all. Has anyone here gotten to use Multichassis PPP Multilink? >All of the documentation I read keeps referring to dial-up and Access >Servers, but one Cisco doc says: > >"MMP is supported on the Cisco 7500, 4500, and 2500 series platforms and on >synchronous serial, asynchronous serial, ISDN BRI, ISDN PRI, and dialer >interfaces." > >Does this mean I can use this to bond multiple T1 between different >routers? Here's the scenario. Let's say I have two 7500s at headquarters >and a remote with with two 2500's, each with a single point-to-point T1 >connection back to one of the HQ 7500s (2500A has a T1 back to 7500A, and >2500B has a T1 back to 7500B). Can I use Multichassis PPP Multilink to >combine those two into a single bundle for load-balancing purposes? > >Any input would be appreciated since the Cisco docs aren't very clear as to >what you can/can't do with this protocol. > >Thanks! >Mike W. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37896&t=37892 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
