Constructing bandwidth allocation rules

About bandwidth allocation rules

Traffic cannot be directed to bandwidth buckets until you create bandwidth allocation rules. Bandwidth allocation rules allow, deny or assign categories of connections to bandwidth buckets, which can have various capacities. For example, using the bandwidth allocation rules, you can limit traffic to

Protocols
Traffic flows (client or server or both)
Times of day
Interfaces

As packets arrive, the bandwidth allocation rules are scanned until a match is found. When a match is found, the packets are directed to the appropriate bandwidth bucket.

Creating new bandwidth rules

To create new bandwidth rules, use the New Rule button in the Rules tab on the Network Bandwidth Allocation page (Setup tab > Bandwidth Allocation).

Viewing existing bandwidth allocation rules

If you have existing bandwidth allocation rules, you can view these rules in the Current Bandwidth Allocation Rules table.

The cumulative AND logic of multiple filtering options

If multiple parameters are shown in the filtering options column in the Current Bandwidth Allocation Rules table, their application follows AND logic. To be included in a listed bandwidth management rule, a connection must match all the parameters specified in the rule filtering options, not just one parameter. Therefore, the filtering options in the following example indicate that Rule 1 applies only to streaming (RTSP and MMS) connections that are to and from upstream servers or parent appliances and are active from 7:30 a.m. to 7:30 p.m. and are received or transmitted through interface ns0 on this appliance.

Rule #	Protocol	Bandwidth	Filtering Options
1	Streaming	Pipe 1, 100 Mbits/sec	server traffic, 7:30am- 7:30pm, via ns0

Rule 1 does not apply to streaming server traffic connections that are active from 7:30 a.m. to 7:30 p.m. but received or transmitted through the ns1 interface.

First-numbered rules take precedence

If multiple bandwidth allocation rules are configured for one NetCache appliance, the rules are applied in the order in which they are numbered in the Current Bandwidth Allocation Rules table. If a category of connections is included in two bandwidth allocation rules that assign it to two different bandwidth buckets, the earliest numbered rule determines the bandwidth bucket to which this category of connections is assigned.

Well-ordered rules example

In the following bandwidth allocation rules example, although both Rule 1 and Rule 2 could apply to RTSP connections received or transmitted through NetCache appliance interface ns0, Rule 1, which is the first rule applied, effectively assigns those connections to bandwidth Pipe Number 1. Rule 2 applies only to those streaming (RTSP and MMS) connections not received or transmitted through interface ns0 and assigns these connections to bandwidth Pipe 2.

Rule #	Protocol	Bandwidth	Filtering Options
1	Streaming	Pipe 1, 100 Mbits/sec	via ns0
2	Streaming	Pipe 2, 50 Mbits/sec	--

Misordered rules example

If, by accident, the rules are reversed, as in the following example, then the new Rule 1 would apply to all streaming connections and assign these connections to bandwidth Pipe 1. No streaming connections, not even those received and transmitted through interface ns0, would be passed to Rule 2 and be assigned to bandwidth Pipe 2.

Rule #	Protocol	Bandwidth	Filtering Options
1	Streaming	Mmbits/sec	--
2	Streaming	Mmbits/sec	via ns0

Note
If necessary, you can change the order in which your bandwidth allocation rules are applied. For more information, see the Appliance Manager online Help.