VXML Gateway Cannot Cache Audio File After The File Successfuly Loaded

Introduction

This document describes how to troubleshoot audio file cache issue in Voice Extensible Markup Language (VXML) gateway after successfuly loaded.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

Cisco Unified Contact Center Enterprise (UCCE) comphrensive call flow

Components Used

This document is not restricted to specific software and hardware versions.

Problem

When caller dials contact centre number, few seconds silence is heard and then audio prompt.

After verification VXML gateway, the audio file from primary Cisco Voice Portal (CVP) media server is not in the cache, the same audio file from secondary CVP media server cache.

Manually load the audio file from CVP primary media server, and it shows successful, but the file is listed as non-cached entries.

           Non-cached entries
         ==================

Ref   Size
---   ----
1     17810
url: http://10.66.75.48/en-us/app/test/2.wav
1     17810
url: http://10.66.75.48/en-us/app/test/3.wav

Troubleshoot

Enable dubug http client all, and make a test call.

From the log, there is one attribute

Cache-Control:no-cache

Jan 10 03:05:13.949 UTC: //1268364//HTTPC:/httpc_msg_read: Start processing 536 bytes data
Jan 10 03:05:13.949 UTC: //1268364//HTTPC:/httpc_msg_read: Stored msg. body: len=536
Jan 10 03:05:13.953 UTC: //1268364//HTTPC:/httpc_socket_read: socket readable fd: 0
Jan 10 03:05:13.953 UTC: //1268364//HTTPC:/httpc_socket_read:
Jan 10 03:05:13.953 UTC: read data from the socket 0 : first 400 bytes of data:

<?xpacket end="w"?> Cr8rT(Unprintable char...)000FFFFFFBEFFFFFFEFFFFFFFCAFFFFFFFE000540100000000000000000000000000000000000000000041646F626520536F756E64626F6F7468204353352028584D50446F634F7073044495350400010004C495354FFFFFF92000494E464F494352441A000323031362D30332D30315431353A32303A30332D30363A30300494152540000494E414D0000
Jan 10 03:05:13.953 UTC: //1268364//HTTPC:/httpc_msg_read: Start processing 492 bytes data
Jan 10 03:05:13.953 UTC: //1268364//HTTPC:/httpc_msg_read: Stored msg. body: len=492
Jan 10 03:05:13.953 UTC: //1268364//HTTPC:/httpc_socket_read: MSG_COMPLETE: rsp_code(200),msg(185FD39C)URL:http://media/en-us/app/Beacon/ROS_Monitor.wav, fd(0)
Jan 10 03:05:13.953 UTC: processing server rsp msg: msg(185FD39C)URL:http://media/en-us/app/Beacon/xxxxxx.wav, fd(0):
Jan 10 03:05:13.953 UTC: Request msg: GET /en-us/app/Beacon/ROS_Monitor.wav HTTP/1.1
Jan 10 03:05:13.953 UTC: Message Response Code: 200
Jan 10 03:05:13.953 UTC: Message Rsp Decoded Headers:
Jan 10 03:05:13.953 UTC: Cache-Control:no-cache
Jan 10 03:05:13.953 UTC: Date:Wed, 10 Jan 2018 03:05:09 GMT
Jan 10 03:05:13.953 UTC: Content-Length:114386
Jan 10 03:05:13.953 UTC: Content-Type:audio/wav
Jan 10 03:05:13.953 UTC: ETag:"e9d02a87074d11:0"
Jan 10 03:05:13.953 UTC: Last-Modified:Tue, 01 Mar 2016 21:22:58 GMT
Jan 10 03:05:13.953 UTC: headers:
Jan 10 03:05:13.953 UTC: HTTP/1.1 200 OK
Cache-Control: no-cache
Content-Type: audio/wav
Last-Modified: Tue, 01 Mar 2016 21:22:58 GMT
Accept-Ranges: bytes
ETag: "e9d02a87074d11:0"
Server: Microsoft-IIS/7.5
X-Powered-By: ASP.NET
Date: Wed, 10 Jan 2018 03:05:09 GMT
Content-Length: 114386

Solution

The root cause of the issue was found after lab-recreation. These steps were taken to re-create the scenario:

Step 1. Under CVP media server created a test folder in this file path:

C:\inetpub\wwwroot\en-us\app

Step 2. Under IIS manager, find the folder that you just created and double click the folder

Step 3. Double click HTTP Response Header, as shown in this image

Step 4. Click add on the right panel and input the attributes as shown in this image

Name:  Cache-Control

Value: no-cache

Verify

Step 1. Load audio file CVP Media server IP address/en-us/app/test1.wav before add the attribute in IIS test folder

  Cached entries
           ==============

entry 150,  1 entries
Ref   FreshTime   Age          Size        context
---   ---------   ---          ----        -------
2     86400       360          17810       0
url: http://10.66.75.48/en-us/app/test/1.wav

Step 2. Add Cache-control with value no-cache and load audio file from test folder

  10.66.75.48/en-us/app/test/2.wav

  10.66.75.48/en-us/app/test/3.wav

 These two audio files are now listed in the non-cached entries:

    Cached entries
           ==============

entry 150,  1 entries
Ref   FreshTime   Age          Size        context
---   ---------   ---          ----        -------
2     86400       360          17810       0
url: http://10.66.75.48/en-us/app/test/1.wav

Non-cached entries
         ==================

Ref   Size
---   ----
1     17810
url: http://10.66.75.48/en-us/app/test/2.wav
1     17810
url: http://10.66.75.48/en-us/app/test/3.wav

Step 3. Load audio file from other folders

10.66.75.48/en-us/app/whisper.wav

It shows that only test folder affected by the attribute.

Maximum memory pool allowed for HTTP Client caching = 15000 K-bytes
Maximum file size allowed for caching = 500 K-bytes
Total memory used up for Cache = 36901 Bytes
Message response timeout = 30 secs
Total cached entries     = 2
Total non-cached entries = 2

           Cached entries
           ==============

entry 150,  1 entries
Ref   FreshTime   Age          Size        context
---   ---------   ---          ----        -------
2     86400       360          17810       0
url: http://10.66.75.48/en-us/app/test/1.wav

entry 166,  1 entries
Ref   FreshTime   Age          Size        context
---   ---------   ---          ----        -------
1     4691902     2495         17810       0
url: http://10.66.75.48/en-us/app/whisper.wav

           Non-cached entries
         ==================

Ref   Size
---   ----
1     17810
url: http://10.66.75.48/en-us/app/test/2.wav
1     17810
url: http://10.66.75.48/en-us/app/test/3.wav

Related Information

https://support.microsoft.com/en-au/help/247404/how-to-modify-the-cache-control-http-header-when-you-use-iis