Include VoIP in the Business Case--The original business case included the maintenance costs of the existing TDM solution, the cost of upgrading it, and Moves/Adds/Changes/Deletes. It was a platform and technology swap. In the future, I would include VoIP for long distance, toll free and call centers, conferencing, and work-from-home employees. This means upgrading the WAN and putting all the intelligence in the data center, which expands the scope. Part of the telecom savings goes towards the network upgrade.
Not Ultra-Reliable--Voice is another application on the network, so if the network goes down, voice services are down too. The top reasons the WAN goes down are local telecom access and power problems. When they are down, doing most types of work is not possible. As IT looks to become greener, is having dial tone when all else is down worth it in this day in age where everyone carries a cell phone?
Improve Voice Quality--In the first generation of IP phones, the voice quality was lacking because of voice compression, cheaper electronics and speaker phones, additional delay, and lack of quality monitoring. Wideband audio on a high end phone sounds great and bandwidth gets cheaper every year. For those of us who are part of the older population, good audio makes a big difference, not to mention the perception to the customer.
Soft-phone Integration--While I do not believe that audio should come through the PC due to supportability challenges, I do believe that all the enhanced functionality should reside on the PC. Call center, presence, collaboration, messaging, directories, and all advanced phone features should be software based. The hard phone is there to deliver basic phone capability and great quality audio, not for a large fancy display.
SIP Standards Based--Phones are about 60% of the capital cost for the project. Getting a phone that is standards based so that it can work with any number of vendor systems offers some long term flexibility. SIP certification is important--http://www.sipforum.org/sipconnect
C-Suite Buy-in--Executives and their administrative assistants are power users of a phone system. If they cannot hit #2# to mark a message urgent, have speed dialing buttons for every senior manager, or easily conference in multiple parties, then they will not be happy. Requirements gathering, testing, training, documentation, and real-time support are critical. And if they are not happy...
Brown-outs--Have the processing capacity plus the throttling to handle short network and/or data center outages. When vendor XYZ says they can support a certain number of phones on a centralized system, ask them what would happen if all the users were to pick up the phone and dial at the same time.
Monitoring--VoIP is a sensitive network application and a lot of times it is the "cannery" of the network. Investing in the monitoring tools will help when a user calls and reports poor voice quality. Troubleshooting intermittent problems can be very difficult.
VoIP/SIP Security--Treating all SIP trunking as external IP connectivity that needs to go through a DMZ with a Session Border Controller. Use SBCs that are carrier grade and certified and that support SIP-TLS and S-RTP.
IPT is a critical step as organizations move strategically towards Unified Communications. An IPT project should be seen as a communications upgrade, not just as a technology swap to save a few dollars.
