SIP

Hardly a day goes by lately when a network operator or next-generation solutions provider doesn’t announce some level of support for the IP Multimedia Subsystems (IMS) industry standard. Intervoice, an established telecommunications solutions provider, for example, just added support for IMS network architectures within its Omvia Media Exchange Platform. Large companies like Nokia and Vodafone are partnering to standardize on IMS. And Brasil Telecom recently announced plans to incorporate IMS elements in its IP communications network. Almost every vendor has plans, trials, or deployments of IMS today.

 

But what exactly is IMS and how is it bringing together fixed and mobile networks while simultaneously helping to bridge the gap between circuit-switched and packet communications? The IMS next-generation networking architecture offers a standard for network operators who want to provide fixed and mobile multimedia services. Developed by the 3rd Generation Partnership Project (3GPP), the specification uses the Session Initiation Protocol (SIP) to run multimedia services over packet- and circuit-switched networks. IMS uses standard IP protocols as defined by the Internet Engineering Task Force (IETF) for support of Internet services while also supporting standard cellular technologies for mobile roaming.

 

IPcommunications.com spoke to Walt Brown, a network systems architect for Intel’s Communication Infrastructure Group, to find out exactly why IMS contains the magic bullets that will help bridge circuit- and packet-switched communications as networks evolve to the next generation of functionality. Brown also works on the Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN) group, a standardization body of European Telecommunications Standards Institute (ETSI). TISPAN incorporates elements of 3GPP IMS in its next-generation network architecture. The organization focuses on fixed networks and convergence with the goal of promoting a subsystem-oriented architecture in which network resources, applications and user equipment are standards based and common to all subsystems.

 

“3GPP, TISPAN, ATIS [Alliance for Telecommunications Industry Solutions] and other groups are very concerned that the network evolve successfully. You want to move to a single fabric rather than having two fabrics out there, but you can’t just throw away existing investments in circuit switching,” said Brown. He added that reporting, management and provisioning infrastructure investments, combined with other operational costs represent a much larger investment than actual switches. Brown said standardization efforts are largely focused on solving problems in an IP world with consideration for the large number of legacy technology and infrastructure solutions in use today.

 

Brown said that when TISPAN, which is composed of carriers, service providers, equipment manufacturers and regulators, first began looking for a common service delivery architecture, IMS was an obvious choice because of its stability. IMS is at the core of Release 1 of TISPAN’s service delivery architecture, and access control, user authentication, service delivery and integration sessions are largely based on the IMS standard. Brown added that the organization is now formulating Release 2, which will extend outside the core network to improve the integration and convergence processes end-to-end. He said the next release would include an emphasis on integration of core networks with emerging enterprise networks. Other priority issues in the next release include mobility, interactions with home networks, enhanced identification and addressing, and end-to-end security, privacy, and confidence.

 

According to Brown, 3GPP, TISPAN and other standards bodies are increasingly taking end-user needs into consideration as they work on evolving next-generation networks and services. “As multimedia devices get more complex and are used in wider applications, end users have more complications,” said Brown. He added that wireless mobility for LANs has added complexity and choice for developing devices and services. With cellular networks and WiFi telephony available for voice services, creating the appropriate end user devices and charging for complex services becomes more difficult, but the choices become more varied.

 

“One of the big problems is that there are two sets of history coming at the marketplace,” said Brown. “On the PC side everything is new and there aren’t a lot of user expectations for new product concepts. The other dynamic is that we’ve had voice and phone communications for over 100 years and there are social, end user, governmental and regulatory expectations.” Brown said combining devices and services is one challenge, but converging two very different attitudes toward delivering products may be an even bigger challenge. That’s where groups like 3GPP and TISPAN come in, trying to build a bridge between people and attitudes, as well as networking environments.

 

At the heart of the new generation of solutions are platforms and technologies like those offered by Intel, built on common modular standards such as IMS. The flexibility of these types of solutions enables easy interoperability of products and services from both the circuit and packet-switched worlds.

 

Brown added that there are bound to be segments of the communications industry that are resistant to change, but that more and more industry groups are realizing the value of standards like IMS. “We all have to work together on this,” said Brown. “The more participation, the faster we can come to convergence, improve the delivery of next-generation services, and make interaction with technologies a useful and pleasurable experience for everyone.”