Session Border Control for Media Transcoding

As next generation architectures are adopted across the wireline and wireless operator community, VoIP standards will play a far more prominent role in the delivery of end-to-end voice services.  Wireless and wireline networks have different characteristics and this has led standards bodies to select different codecs to run over those networks.  

The flexibility of packetized voice technologies and the diversity of deployment methods from carrier to carrier, combined with the wide variety of end devices with differing capabilities, will result in a growing number of interoperability issues both within a carrier domain and as disparate providers interconnect their networks.

As integrated VoIP infrastructures evolve, the broad range of media encoding options, combined with a lack of device and network standardization, will escalate the need for transcoding functions within the access layer and at service provider peering points. A processor intensive feature, this network resource must be enabled as cost effectively as possible, with diverse deployment options that match the specific needs of a particular operator or network implementation. 

Perimeta transcoding architectures

The Perimeta session border controller (SBC), from Metaswitch, provides network architects numerous options for normalizing media flows between devices and carrier infrastructures and minimizing the use of transcoding.  When irreconcilable codec mismatches are identified within the SIP signaling call set-up and negotiation messages, Perimeta dynamically routes the media traffic through the most efficient transcoding path, always guaranteeing the highest quality of experience.

Supporting a broad range of standard definition and high definition codecs prevalent in wireline, wireless and internet VoIP communications, Perimeta can ensure media interoperability in practically any internetworking eventuality.  Architectural options ensure that transcoding resources can be shared between multiple platforms, allowing for both centralized and distributed transcoding deployments.  These resources can also be expanded independently from the core SBC signaling, allowing a simple growth path to support any transcoding scale.  A range of services, spanning audio, fax and video can all be supported.

Perimeta provides two distinct transcoding options, which can be mixed as needed in any given deployment.

Software transcoding

Perimeta implements transcoding in software that can be run on any supported platform, including COTS, virtualized or cloud.

Software transcoding provides the most economical solution to transcoding at small volumes and a competitive solution at larger volumes.  The portability to run on different platforms ensures that a right-size solution can be found for any deployment.  It also ensures that expensive, specialized hardware is not left stranded as transcoding requirements move or change with time, and that support for new codecs can be added in a flexible and agile manner.

Hardware transcoding

Perimeta also offers transcoding using an add-on PCIe card, that can be installed in any suitable COTS server and are compatible with virtualized SBC systems.  

These cards use state-of-the-art DSPs to provide unrivalled transcoding density and power efficiency for high-scale systems.  

Which to choose?  The choice of software and hardware transcoding is a complex one that depends on a number of different factors including traffic patterns, codec preferences, scale and architecture.  Metaswitch is uniquely placed to offer you advice and products that allow you to select the right choice for your network today and tomorrow.

Hardware transcoding capacity per DSP board on compatible Perimeta platforms

Software transcoding capacity on Perimeta ISC 6320

Software transcoding capacity on Perimeta MSC 6340

Software transcoding capacity on Perimeta ISC on Dell R630

Software transcoding capacity on Perimeta MSC on Dell R630