Can SIP run on top of 802.11?
Of course Session Initiation Protocol (SIP) can run on top of 802.11. We've deployed 802.11n in the schools that Telecomworx serves, and when it comes to voice in this case it is vital to address how your access points (APs) are designed. The APs we use are entry point APs that we can upgrade to allow virtualization (of the controller to the server), fast roaming and the ability to move seamlessly between APs without voice interruption. When we tested several SIP clients for Google Voice, my favorite client was Bria 3 from CounterPath. In addition, we found that Talkatone and Walkie-Talkie are two cool applications that tend to work really well on the iPhone. And guess what? There were no extremely noticeable interruptions between the APs -- although we were able to detect when our conversation was handed off from one AP to the next.
We are also excited about the VoWiFi system, and you should be too. It is important to note that we deploy ADTRAN Bluesocket NV160s, using their Netvanta 1534/1544 platform with Power over Ethernet (PoE) and an onboard Wi-Fi controller. We will need to upgrade the APs if the schools decide to deploy clients on staff cellphones in order to assure that handoff, but first we will push what we have to the limits before buying the license upgrades for the APs.
This was first published in February 2013