How it is to use Java SIP Servlets for developing a SIP/VOIP server side application which has high demands in terms of performance, scalability, availability, maintainability etc. Is java sip servlets great enough or something else available is a better choice of doing so.
Apart from this, are there any reusable frameworks/libraries that can boost the development speed of server side sip application?
Greatly appreciate any help of this.
SIP Servlets is only an API, so you cannot talk about performance. But you can talk about performance when it comes to the implementations. There are only a few implementations of JSR-289 (SIP servlets 1.1) and I used Mobicents, which is built on top of Tomcat or JBoss. So when it comes to performance, scalability, availability, maintainability etc a big role is played by these application containers. And I'm sure you can find plenty of references about all these.
Are there any reusable frameworks/libraries that can boost the development speed of server side sip application? Not sure what you mean. If you refer to something like what Spring framework is for servlets, I'm not aware of such.
But SIP Servlets are pretty comprehensive spec and even include utility classes for a back-to-back UA. Though documentation is pretty shallow and you'll need to scan through various examples to implement something useful.