About bandwidth allocation

What is bandwidth allocation?

The NetCache bandwidth allocation feature enables you to control the total bandwidth capacity that specified categories of connections can collectively consume on the NetCache appliance.

Using the NetCache Manager fields associated with bandwidth allocation, you can:

Set aside portions of your total NetCache bandwidth capacity into various-size capacity bandwidth buckets.
For example, you can limit all in-bound streaming traffic to a given maximum bandwidth or limit the bandwidth usage on an interface.
Assign connections matching a specified set of properties, such as protocol, source or destination IP addresses, and in-bound (server-side) or out-bound (client-side) communication to a bandwidth bucket.
For example, you can restrict aggregate bandwidth by single protocol (IP, TCP, UDP, MMS, RTSP, HTTP), by a streaming protocol set (both RTSP and MMS), or by an application (ContentDirector).
Deny NetCache service to a category of connections completely, or allow NetCache service to the same category of connections with no bandwidth restriction whatsoever.
For example, you can deny all FTP traffic to a specified server.

How does bandwidth allocation work?

All connections assigned to a specific bandwidth bucket share the total bandwidth space allocated for that bandwidth bucket. The NetCache appliance enforces the bandwidth limit, if necessary, by using buffers to space out both incoming and outgoing packets.

As a result, TCP connections, as well as protocol connections based on UDP, gracefully use the specified bandwidth bucket with a minimum of burstiness, allowing NetCache to enforce the bandwidth allocation rules efficiently.

Note
As a partial alternative to bandwidth allocation, NetCache supports streaming bandwidth management rules that simply allow or deny categories of streaming connections on the basis of their requested bandwidth. For more information, see the streaming information in the online Help.

Elements of bandwidth management

To implement bandwidth management, you must create bandwidth allocation buckets and bandwidth allocation rules. Bandwidth allocation buckets define the bandwidth, admission control, and dynamic creation properties that control how packets are throttled on the network. Bandwidth allocation rules define the conditions under which a packet is sent to a specific bucket.