I was thinking a good place to start off a VoIP discussion was with the topic of deploying VoIP! As many of us know voice has become a common staple in many IP networks and is typically designed into the network from day 1. However there are definitely still networks out there that are not currently running VoIP and are looking to implement these VoIP & mobility services. If you have had the opportunity to integrate voice into an existing IP network you know there is definitely some prep work that will have to be done. After all, if implementing VoIP into a network was a simple thing we wouldn't get paid the big bucks right?
Like many implementations and deployments after you have done a couple, they become easier and you learn how to avoid the more common pitfalls and setbacks. Many people have went as far as to create a 'checklist' of sorts for making VoIP deployments easier providing an simpler work flow to follow. Below are going to be a few bullets from my own checklist:
Power - How do you plan on powering VoIP equipment (Hand held phones, conference phones, desktop phones, etc), sure you can use power bricks or you can rely on PoE (Power over Ethernet) switches this way you don't have to worry about the additional overhead of the power bricks (ordering, inventory, cost, shipping, etc). You may also have to consider the power budget of those switches, depending on what (if any) other PoE capable devices are already receiving power. Remember many wireless-N & AC access points require more power than the older 802.3af standard could provide to fully operate, or perhaps you also have PoE capable surveillance systems? If you are deploying wireless handheld phones do you need some larger multi-device charging docks, or should you account for spare batteries?
Guides for the end users - This may sound trivial but we can't forget about the end users. Making sure the users know how to access their voice mail and use the IP Phones the way they need ensures we get fewer questions from the end users, which makes everyone's life easier.
QoS (Quality of Service)– This is definitely a very important aspect in every VoIP network. Without QoS to protect the signaling and RTP audio streams from the rest of the IP data network traffic the VoIP system could be rendered completely un-usable. Where should you create your trust boundary and how should you allocate your queue's?
IP Addressing/VLAN Assignment - Depending on the size of your deployment, you might have to take some extra care into your address assignments and DHCP scope creations (Do you need to create any special DHCP Options?). What if your routing schema is summarizable and hierarchical to the core of your network how can you maintain that standardization?
Authentication/Security - How are the IP Phones going to authenticate to the network will you need to deploy certificates or require the phones to participate in Dot1X authentication? Do you need to consider security compliancy with any governing bodies? (PCI, HIPPA, CJIS, SOX, etc)
Site Surveys - More aimed toward VoWLAN (Voice over Wireless LAN) deployments. The RF spectrum is the layer-1 medium for wireless networks, performing a site survey & knowing the RF environment of your WLAN gives you an amazing advantage from a support and maintenance perspective. If you are aware of the extent of your coverage and what interferes are in your environment you can either eliminate those obstacles or work around them eliminating issues before they even arise.
Those are just a few topics, what items are on your VoIP deployment/readiness checklist that you look out for and why do you consider them to important aspects during a VoIP deployment?