PCMM Evolves around QOS

PacketCable Multimedia (PCMM) actually provides ways for cable operators to enrich their voice businesses even when subscribers use other nonMSO VoIP services. Because PCMM lays down rules for enhanced quality of service (QoS) that is application-specific, not network-specific, cable operators can charge consumers extra for QoS on such noncarrier-based VoIP offerings as Vonage, said Kurt Dobbins, founder-CTO of Ellacoya Networks and Susie Kim Riley, founder-CTO of Camiant, during a presentation at SCTE Cable-Tec Expo. PacketCable’s primary purpose is to enable multimedia applications to run reliably on cable networks. For cable operators, this means MSO-specific applications can be assigned a level of quality assurance; for noncable providers running applications on cable broadband networks, it means obtaining a level of end-to-end QoS for services such as VoIP that are not specifically delivered by the MSO. In this instance, a cable operator could offer a level of application-specific QoS for a voice service such as Vonage, charging either Vonage or the subscriber to make certain calls are delivered reliably. “It’s all about making the service better, protecting the brand,” said Dobbins. For cable-provided applications, such as MSO-branded voice services, PCMM adds a natural layer of quality and reliability that is under the auspices of the network operator. For noncable applications—gaming or voice services riding on the MSOs’ networks but not specifically supported by the MSO, or in partnership with the MSO—it offers the opportunity to get a level of QoS that enhances the product and ensures subscriber satisfaction. Dobbins suggested that subscribers could “do this on an application basis” by informing the cable operator what services, if any, should receive enhanced QoS and even a bit of dedicated bandwidth. Operators, he said, could offer this to subscribers for an additional monthly or one-time fee. PCMM assigns specific applications to specific two-way QoS-enabled DOCSIS flows between cable modems and the operator and allows applications to be marked with DiffServ Code Point (DSCP) values assigning priority through the network. This architecture, Dobbins said, allows for a “transition for broadband service providers to move away from fixed bandwidths and fixed speeds (to) deliver applications on an individual subscriber basis.” This “QoS enhancement that you can apply to any applications is important to subscribers,” he continued. While enhanced voice services certainly benefit from PCMM, the specification’s primary purpose really is to “de-couple QoS” from applications so that the applications can do their thing while the network handles the rest, said Riley. In particular, Riley suggested a method by which policy servers will handle all the QoS and other functionality to improve operational efficiency so “applications can scale better.” The policy server, therefore, needs to be deployed and integrated with the OSS, and the PCMM needs to be integrated with the policy server. In its next iteration, PCMM should also improve the connection of SIP-based services with the public switched telephone network (PSTN) and help cable operators maintain peering relationships directly with fellow MSOs using the IP network and not moving to the PSTN, Riley said. “Now you can have services that transcend the cable network,” even moving out to the wireless network. This, she said, is a “quantum leap in communications” that will drive the cable industry behind the triple play.