ip cef load-sharing algorithm

Usage Guidelines

The original CEF load sharing algorithm produced distortions in load sharing across multiple routers due to the use of the same algorithm on every router. When the load sharing algorithm is set to universal mode, each router on the network can make a different load sharing decision for each source-destination address pair which resolves load sharing distortions.

The tunnel algorithm is designed to more fairly share load when only a few source-destination pairs are involved.

Examples

The following example shows how to enable the CEF load sharing algorithm for universal environments:

Router(config)# ip cef load-sharing algorithm universal 1 

IP Switching Commands: ip cef accounting through ip route-cache 

Load Balancing with CEF 

Fine-tuning CEF load-sharing 

CEF per-destination load sharing algorithms 

CEF load sharing details 

Module Support on Cisco’s Integrated Services Routers Generation 2

From: http://www.cisco.com/en/US/prod/collateral/routers/ps10538/aag_c07_563807.pdf

Inverse Multiplexing Over ATM (IMA) on Cisco

Introduction

Inverse Multiplexing over ATM (IMA) involves inverse multiplexing and de-multiplexing of ATM cells in a cyclical fashion among physical links grouped to form a higher-bandwidth and logical link. The rate of the logical link is approximately the sum of the rate of the physical links in the IMA group. Streams of cells are distributed in a round-robin manner across the multiple T1/E1 links and reassembled at the destination to form the original cell stream. Sequencing is provided using IMA Control Protocol (ICP) cells.
In the transmit direction, the ATM cell stream received from the ATM layer is distributed on a cell by cell basis across the multiple links within the IMA group. At the far-end, the receiving IMA unit reassembles the cells from each link on a cell-by-cell basis and recreates the original ATM cell stream. The image below displays how cell streams are transmitted across multiple interfaces and recombined to form the original cell stream. The receiving interface discards the ICP cells, and the aggregate cell stream is then passed to the ATM layer.
Periodically, the transmit IMA sends special cells that permit reconstruction of the ATM cell stream at the receiving IMA. These ICP cells provide the definition of an IMA frame.
Cell streams are transmitted across multiple interfaces and recombined to form the original stream.

Inverse Multiplexing Over ATM (IMA) on Cisco 2600 and 3600 Routers
Inverse Multiplexing for ATM (IMA) FAQ
Understanding the Variable Bit Rate Real Time (VBR-rt) Service Category for ATM VCs