The term unified communications implies a range of services. However, voice is a key service, and it should be the starting point for hybrid communications when moving telephony from traditional analog or time division multiplexer infrastructure to voice over IP running over broadband.
Your current analog PBX provider can help with the hybrid part of the migration, as it will need to provide the gateway between the analog and VoIP worlds. Depending on the vendor, this might be called a media gateway, session border controller or another term.
The primary service of unified communications (UC) is VoIP, and VoIP migrations have been occurring for quite some time. While your PBX vendor might want you to take the plunge into full-blown UC right away, it's best to inquire about the practicality of taking a phased approach. Telephony and communications in general are a crucial part of the business, and they should be implemented with care.
Taking the first step into hybrid UC
Limit exposure by focusing phase one of your hybrid communications migration on migrating lower-priority, outbound convenience calling to the VoIP gateway. This way, the system can run and work out the kinks without affecting important calls, like those to inbound call centers.
Your UC system should be able to provide you with an easy fallback if you decide VoIP sessions aren't performing as required. A fallback plan can be as simple as a configuration change in your PBX.
While LAN bandwidth could be an area of concern during a UC migration, VoIP is unlikely to experience LAN-based issues. VoIP sessions use little bandwidth, and problems like latency, jitter and packet loss are rarely an issue on LANs. It's certainly good to understand the network characteristics of your LAN before layering in new applications, but most LANs have plenty of capacity for VoIP.
Maintaining quality during a hybrid communications migration
One big factor to consider is the broadband network your VoIP and UC sessions will traverse. Moving from TDM dedicated lines to free-for-all broadband is one of the biggest moves you can make in the networking world.
Think about it: Your media gateway can work perfectly, and yet calls still experience miserable voice quality -- all because of the economical, but potentially unreliable, broadband network that is now your new UC highway. So, what do you do?
Quality of service (QoS) can save the day. The media gateway and the broadband network all need to work in concert to provide sufficient bandwidth and low latency across the network so voice quality will be acceptable.
QoS is a lot more than just using various packet markup schemes, like Differentiated Service Code Point and type-of-service bits. You must have a smart WAN infrastructure -- think software-defined WAN -- that recognizes your various applications and provides the QoS along the way. Without this kind of intelligent WAN infrastructure, even the most detailed packet marking is essentially a mark-and-pray operation.
An important part of your hybrid communications migration should be making sure the broadband service over which your traffic will traverse can meet your service-level requirements. You may find that basic broadband connections to your branch offices work fine for web browsing, but that you will need to upgrade to pricier business class broadband to get the service levels required for UC.
Keep in mind, too, that while leased line bandwidth is consistent day in and day out, broadband bandwidth can change during the day and impact your UC applications.
Trust but verify with testing and analytics
In the networking world, trust but verify translates into test before you deploy. For example, you can augment your unified communications architecture testing with network emulators that allow you to inject degradation, such as high packet loss or latency, into a test environment to see how your VoIP and UC applications fare.
Ultimately, your success will be determined by how happy your users are. Because happiness is subjective -- and subject to change without notice -- you need to document your success with ongoing assessments.
Because VoIP is a key UC app, look for voice quality measurements that are available within your system, such as mean opinion score, Perceptual Evaluation of Speech Quality or Perceptual Speech Quality Measure scores, which can objectively measure your VoIP session quality.
Be sure to find out what kind of analytics your vendor's system can provide for your UC gateway. Features to look for include whether the analytics break traffic down by traffic type, individual user or other means. Other important options include whether the analytics provide real-time and historical data. If you have the right analytics in place, you'll have the tools you need to document the success of your migration to hybrid UC.