Here at ETEL 2007, The VOIPSA folks just presented an excellent discussion on VoIP security issues.
The fact is, we all know that security is going to be a huge issue in VoIP (or is supposed to be already), and despite all the attention, it seems that it doesn’t get the effort it deserves; it’s just not a crisis yet.
Hoping to avert the crisis, the VOIP Security Alliance http://www.voipsa.org fulfills an important role: getting folks talking about security and VoIP, and more importantly, offering solutions.
Check out their excellent website, join the really top-notch mailing list, and get yourself informed. Someday very soon we’ll be glad that these folks have done so much already. When the pain comes, there will be medicine.

