Alteon Application Switch Operating System Application Guide
Bandwidth Management
Document ID: RDWR-ALOS-V2900_AG1302
765
Note:
The soft and reserved, or Committed Information Rate (CIR), limits of each contract are not
part of the grouped contract's calculation, and remain set at their individual contract's levels.
For a group contract configuration example, see
Configuring Grouped Contracts for Bandwidth
.
IP User Level Contracts for Individual Sessions
Bandwidth Management includes user limits, which are policies that can be applied to a contract that
specify a rate limit for each user who is sending or receiving traffic in that contract. The contract can
be configured to identify a user by either the source or the destination IP address in the packets.
The user limit policy monitors the amount of bandwidth used per second, and drops any traffic that
exceeds the configured limit. To monitor a user's bandwidth, Alteon creates an IP user entry that
records the source or destination IP address, and the amount of bandwidth used.
This feature is used to limiting bandwidth hogging by a few overactive internet users with
unimportant traffic (for example peer-to-peer movie sharing), which may end up denying other
users with legitimate traffic from their fair share of the bandwidth. Because user limiting is
performed on a per-contract basis, different types of traffic can be classified into different contracts
and can have different user limits applied according to the class of traffic. Because user limiting for a
contract is optional, it can be set for contracts where fair-sharing of bandwidth is important, and not
set for the contracts where fair-sharing of bandwidth is not important or desirable.
The following are examples that further explain how user limits work:
Example
User Limits are Overwritten by the Contract Hard Limit
The IP user limit is configured in addition to the contract's hard limit. However, the contract's hard
limit overrides the individual user entry's user limit.
An example contract has a hard limit of 10 Mbps and a user limit of 1 Mbps. If there are 20 IP users
for the contract with an offered traffic rate of 1 Mbps each (for a total offered traffic rate for the
contract of 20 Mbps), the total traffic allowed for the contract does not exceed the hard limit (10
Table 66: Bandwidth Reallocation in Grouped Contracts
Resource
Contract 1
Contract 2
Contract 3
Contract 4
Total
Hard limit
10
1
1 – (All units in Mbps)
20
30
40
100
Actual traffic
15
20
20
60
115
Unused bandwidth
NA
NA
10
NA
10
Bandwidth over Hard 5
0
NA
20
25
Extra share
2
2 – Denotes the bandwidth over the hard limit in contract 1, divided by the total bandwidth
over the hard limit for the contract group, multiplied by the total extra share bandwidth.
0
NA
3
3 – Denotes the bandwidth over the hard limit in contract 4, divided by the total bandwidth
over the hard limit for the contract group, multiplied by the total extra share bandwidth
10
Adjusted hard limit
12
20
20
48
100
