Patching telcom infrastructure can become a challenge

As with many priority systems, patching can become an arduous, and even political battle within an enterprise. These priority systems can be deemed so critical by the organization that patching them is viewed as a risk to the business, which is counter-intuitive when thinking from a security standpoint. This is normally the case when these systems run on outdated or legacy operating systems where installing patches would either void a support agreement or where the organization doesn't have the funds or architecture to test the patches' functionality in a QA environment. Read more at the link below:

http://searchsecurity.techtarget.com/answer/Why-is-patching-telecom-infrastructures-such-a-challenge