Tin Cups and String: The Convergent Microsoft UC Blog

If you have just received a SIP 481 error in a trace on your front-end server, and have a recently deployed a custom OCS 2007 R2 UCMA application from your test to production system that is having issues with audio calls, we may have a fix for you.

 The scenario: You build and test a UCMA voice response workflow application on your dev server.  It works great, and you and the customer love the functionality. You take it to the customer site, deploy it to a sep. server (no, NOT the front end server or any other OCS role server people!!), provision the GRUU and all that jazz correctly,  and get ready to bask in customer appreciation. 

The problem: It doesn’t work.  It will “fire up” just fine (we even made it an interactive logging console app to watch it load and process) and then answer and/or make calls to OCS or PSTN users, but the audio it should play into the calling party ear isn’t there.  An app that calls, but won’t interact.  Works on your system but not at the customer.  Great, just great. 

The research:  We did a trace for all SIP and UCMA activity on the FE servers, and saw this:  Start-Line: SIP/2.0 481 Call Leg/Transaction Does Not Exist

We tried a bunch of OCS standard error/communication stuff, but OCS and EV works perfect everywhere.  We then gave up and called into MS dev support.  We had a GREAT engineer (here I’ll name drop, since he really knew his stuff - Ramesh Anantharaju)  with whom we gathered info and explained our scenario.  As part of the testing, we decided to install Visual Studio on the customer server, and run our app in debug from there.  No dice, still fires up and then works without audio. 

We then decided to deploy a basic “hello world” app from the UCMA SDK sample.  As a really quick step before the app Ramesh wanted us to test, we just tried to make a new “hello world” call answer flow app, and up popped the answer to our issue. 

Guesses anyone?  We never installed the UCMA API English Language Pack on the customer deployment server.  All other required items, yes.  Language packs, no. 

And before you ask, NO VStudio doesn’t (currently!) warn you about the dependency when you open an existing project - only on new ones. As of now, we still cannot find any place that this condition is properly logged, but our test show it does generate the admittedly obscure SIP 481, so we thought a post migh5t be in order. 

I know that some may suggest we should have error checked for this on our app server with the logging tools from the reskit, however at this point we can’t get the to show any UCMA events, so no joy there either.  If/when we learn how to get better info out of standard OCS tools on custom apps, I’ll post again.  Cheers all, and happy OCS Deving!

 - Doug

Oh, and as of now, this is the current language pack link:  http://www.microsoft.com/downloads/details.aspx?familyid=30E14C5A-A42C-4D4E-9513-C4B0B8D21086&displaylang=en