A VoIP deployment is an act of intimacy.  One of the great challenges for the deployment team is defining the demarcation point between the phone system, the network and the various applications that integrate withe the phone system.   Clearly, the foundation of a successful deployment is a strong network foundation.   The ability of the network to provide the necessary DHCP services including NTS, IP and vendor specific options are area's that need to be clearly defined.   Who is providing these services?  The existing data network, or the new voice network?  Is the the in place data network infrastructure capable of supporting the addition of low latency, zero packet loss, not jitter voice and video?   Can the in place access level switches support true 802.1Q Vlan functionality?  How will routing between the voice network and the data network be provided and who will be responsible for configuring these services? The VoIP network invariably needs to interface with other applications.  Minimally, the VoIP solution will interact with both the Active Directory system and the contact management system (Outlook, Notes etc.).   Who is responsible for this configuration and problem resolution?  The VoIP solution vendor or the the client?   When the Call Managers fail to work properly because of an undisclosed Proxy Server that was not disclosed in the statement of work (SOW), is that time and effort that the VoIP vendor should eat, or is this an area the client should be responsible for? Any professional that has worked with commuter network technology for any period of time understands that the complexity of integration issues makes these divisions of responsibility very difficult to enforce without jeopardizing an ongoing relationship.  The client wants everything to work better than it worked before the vendor got enveloped.  The vendor wants to provide a key area of expertise without taking ownership for all that came before. Unfortunately, a VoIP deployment is as intimate as a marriage.  You get more than a spouse, you get the entire family.   I often have clients ask me to provide references for my past work.  Clearly, I come up with a list or excellent references.  What I am always waiting for is a client who is smart enough to ask for a list of "disasters".   You would think that clients would want to know how a vendor performed when Murphy ran amuck!   When everything that could possibly go wrong went wrong!  That is the client list you want to review. A VoIP deployment is a marriage between a vision and reality, it is a leap of faith.   The Vendor and the Client need to look past the initial courting and dating, and look down.  We all start out young and good looking.  It is how we deal with the process of design, implementation, operating and the ongoing optimization of both the deployment and the relationship that really determines the ultimate success of a VoIP solution.