Forking SIP requests in an MSPL script

In previous blog posts on Microsoft SIP Processing Language (MSPL), I’ve explained how to essentially intercept SIP requests, such as the INVITE message that initiates a call, and pass them along to a UCMA application for handling by passing a parameter to the ProxyRequest method. In this post, I want to discuss what you can do if you want to “fork” a request, which means you are sending it to multiple endpoints simultaneously. Continue reading “Forking SIP requests in an MSPL script” »

Minimizing performance impact from managed SIP applications

The Managed SIP Application API, which I discussed in the previous post, allows you to manipulate the content and routing of SIP messages in some potentially very useful ways by running an application on a Front End Server. However, when the volume of messages is very large, dispatching them to managed code can have a significant effect on performance. For managed code applications that simply monitor messages, and don’t modify them or change the routing, there is a way to mitigate this performance impact by sending the message details to the application from the MSPL script in a sort of “fire-and-forget” mode, using the DispatchNotification method. Continue reading “Minimizing performance impact from managed SIP applications” »

Modifying SIP headers using the Managed SIP Application API

The Lync Server SDK includes an API, the Managed SIP Application API, which is essentially a more powerful and complex managed-code cousin of MSPL (Microsoft SIP Processing Language). It allows you to create applications that, much like MSPL scripts, reside on a Front End Server or one of the other Lync servers (Edge, Mediation, etc.). Unlike MSPL, however, these are created using managed code. The classes that make up the API, which are contained in the Microsoft.Rtc.Sip namespace, allow you to modify SIP messages and control message routing in a number of ways that are not possible with MSPL. Continue reading “Modifying SIP headers using the Managed SIP Application API” »

Distinguishing IM vs. audio calls in MSPL

Microsoft SIP Processing Language, a.k.a. MSPL, can be handy for changing Lync’s routing behavior, to do things like block or reroute calls based on their origin, or send all calls of a certain type to a UCMA application. In certain cases, when writing MSPL scripts, you may want your script to behave differently depending on whether it is dealing with an audio call or an instant messaging session. It’s not immediately obvious how to distinguish between these two types of calls in MSPL, so I wanted to write up a quick description of how you can do this. Continue reading “Distinguishing IM vs. audio calls in MSPL” »

Rerouting requests to a UCMA application with MSPL

One of the most useful (and most confusing) things you can do with Microsoft SIP Processing Language (MSPL) is change the routing behaviour of Lync Server. There are a variety of reasons why you might want to do this, but in this post I want to discuss a specific case: rerouting calls to a UCMA application. Continue reading “Rerouting requests to a UCMA application with MSPL” »

Default routing endpoints in UCMA

UCMA 3.0 introduced the concept of a “default routing endpoint.” To put it very generally, a default routing endpoint is a single application endpoint that receives any messages that have nowhere else to go. I’ll illustrate further in a moment. When I first heard about this new feature, I could not understand what use it could possibly have. Gradually, over a period of months, situations came up where default routing endpoints turned out to be very handy. Since I figure that other folks might have the same initial reaction of complete confusion when hearing about the default routing endpoint feature, I thought I would write up a bit of explanation on this odd but useful creature in the hope that it will help in others’ development efforts. Continue reading “Default routing endpoints in UCMA” »

Installing and troubleshooting MSPL scripts

In my last post, I described some of the basics of Microsoft SIP Processing Language, or MSPL, using a simple script as an example. That last post ended with a cliffhanger: how does the MSPL script get installed on the Lync Front End Server?

Today, I’m going to answer that question. Continue reading “Installing and troubleshooting MSPL scripts” »

Extending Lync Server routing with MSPL

Recently I’ve taken a number of questions about customizing the routing of messages in Lync Server, which is possible with the Lync Server 2010 SDK. Since most of the how-to material out there is about either UCMA or the Lync 2010 (client) SDK, I thought I would write up a few articles on the basics of what you can do with the Lync Server 2010 SDK, and particularly with Microsoft SIP Processing Language, a.k.a. MSPL. Continue reading “Extending Lync Server routing with MSPL” »