Cisco Cisco Unified Customer Voice Portal 11.0(1)

Gateway Prompt Caching Considerations

When audio prompts are stored on an HTTP media server, proper gateway prompt caching
methods are necessary to optimize both the performance of the gateway and network bandwidth
consumption. Gateway performance decreases by approximately 35-40% if caching is disabled
entirely.

How to Configure Caching on the Gateway

To configure caching on the gateway, do the following:

1. Set the following on the gateway:

–

ivr prompt memory 15000

–

http client cache memory file 500

–

http client cache memory pool 15000

Note: The 'http client cache memory file' represents the largest size prompt file (in Kbytes)
that can be cached. In general, break up customer prompts larger than 500K (about a
minute in length) into smaller, more manageable pieces to facilitate loading and caching.
For example, queue music could be a repetitive loop of a 30 second prompt. Note also
that because the prompts are streamed, the prompt will not be cached unless the whole
prompt is played. Therefore, you must make prompts a manageable size.

2. Synchronize the datetime between the gateway and the HTTP media server.

Note: Synchronization does not have to be exact, but at least within a minute or two. Times
that are not synchronized can cause prompts to never refresh or they will refresh with
every call, both of which are undesirable behaviors.

3. On the media server, set the content expiration (for example 15 minutes).

Note: In IIS, this is done under the "HTTP Header" tab. The gateway prompt will be refreshed
after this time period. The period chosen reflects how often the record prompts and how long
you are willing to wait to have the new prompt load after modification.

How to Determine if the Gateway is Caching Properly

To determine if you have properly configured gateway caching, do one of the following:

•

The IIS log on the media server records every time a client requests a prompt. If caching is
set up correctly, these requests appear approximately every X minutes (X is whatever was

Configuration and Administration Guide for Cisco Unified Customer Voice Portal Release 4.1(1)