Scalable voip mobility intedration and deployment- P5: The term voice mobility can mean a number of different things to different people. Two words that can be quite trendy by themselves, but stuck together as if forgotten at a bus station long past the last ride of the night, the phrase rings a number of different, and at times discordant, bells. | 38 Chapter 2 PSTN integration as the standard case Skype s landline telephone services can be thought of more as special cases has allowed it to be optimized for better voice quality in a lossy environment. Skype is unlikely to be useful in current voice mobility deployments so it will not be mentioned much further in this book. However Skype will always be found performing somewhere within the enterprise and so its usage should be understood. As time progresses it may be possible that people will have worked out a more full understanding of how to deploy Skype in the enterprise. Polycom SpectraLink Voice Priority SVP Early in the days of voice over Wi-Fi a company called SpectraLink now owned by Polycom created a Wi-Fi handset gateway and a protocol between them to allow the phones to have good voice quality when Wi-Fi itself did not yet have Wi-Fi Multimedia WMM quality of service. SVP runs as a self-contained protocol for both signaling and bearer traffic over IP using a proprietary IP type neither UDP nor TCP for all of the traffic. SVP is not intended to be an end-to-end signaling protocol. Rather like Cisco s SCCP it is intended to bridge between a network server that speaks the real telephone protocol and the proprietary telephone. Therefore SCCP and SVP have a roughly similar architecture. The major difference is that SVP was designed with wireless in mind to tackle the early quality-of-service issues over Wi-Fi whereas SCCP was designed mostly as a way of simplifying the operation of phone terminals over wireline IP networks. Figure shows the SVP architecture. The SVP system integrates into a standard IP PBX deployment. The SVP gateway acts as the location for the extensions as far as the PBX is concerned. The gateway also acts as the coordinator for all of the wireless phones. SVP phones connect with the gateway where they are provisioned. The job of the SVP gateway is to perform all of the wireless voice resource management of the network. The
