Alteon Application Switch Operating System Application Guide
Bandwidth Management
764 Document ID: RDWR-ALOS-V2900_AG1302
Grouped Bandwidth Contracts
Alteon uses the concept of multi-tiered, or grouped, bandwidth management contracts. In earlier
releases, a single-level bandwidth management contract was used to manage bandwidth on an
Alteon. BWM contract groups are now configured to aggregate contract resources and share unused
bandwidth within the contract group. A group level contract should contain two or more individual
contracts as defined in Contracts, page 761
.
Based on how much traffic is sent in each contract in the group, the hard limits of the contracts are
adjusted proportionately to their share in the group.
Example Grouped Bandwidth Contract
A group level contract is configured with four individual contracts with rate limits of 10, 20, 30 and
40 Mbps each. Together, the total rate limit of the member contracts is 100 Mbps. If a particular
contract is not using its full bandwidth allocation, Alteon reallocates the bandwidth to the other
members of the contract group by polling bandwidth statistics every second, and recalculating the
bandwidth allocation.
Table 66 - Bandwidth Reallocation in Grouped Contracts, page 765
illustrates how the hard limits of
individual contracts self-adjust when placed into a contract group. The hard limit indicates the actual
hard limits set for each individual contract. Since contracts 1 through 4 are part of a contract group,
the total hard limit allowed for the group in this example is 100 Mbps.
The actual traffic indicates that contracts 1 and 4 have exceeded their hard limits by a total of 25
Mbps. Contract 3 is underusing its hard limit by 10 Mbps.
Because all contracts are members of the group, the unused bandwidth is divided proportionately
between the two contracts that exceeded their hard limits—contracts 1 and 4.
• Contract 1 requests 15 Mbps, which is 5 Mbps over its hard limit. Because contract 1 requests 5
of the 25 Mbps bandwidth over the total bandwidth hard limit for the contract group, it receives
one-fifth of the available extra share, or 2 Mbps. The remaining 3 Mbps that contract 1 requests
is dropped.
• Contract 4 requests 60 Mbps, which is 20 Mbps over its hard limit. Because contract 4 requests
20 of the 25 Mbps over the total bandwidth hard limit for the contract group, it receives four-
fifths of the extra share, or 12 Mbps. The remaining 12 Mbps requested by contract 4 is
dropped.
To Next Page
Loading...
Need help?
General