Which Media Transcoding Strategy Is Right for Your Network?

White Paper

Which Media Transcoding Strategy Is Right for Your Network? (Hint: It might not be the strategy you’re using today) Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

Executive Summary The rapid and rising demand for multimedia mobile devices such as smartphones and tablets has changed the landscape of telecommunications networks. As Communications Service Providers (CSPs) engage in network transformation efforts around Long Term Evolution (LTE) and IP Multimedia Subsystem (IMS) specifications to meet this growing demand, they are also facing new media transcoding challenges brought on by the multiplicity of mobile and legacy devices and the variety of media (in which video will play an increasingly vital role). How CSPs respond to the media transcoding challenge will have a profound impact on their business, as nearly half of all voice/video sessions will require some type of transcoding.

This whitepaper examines requirements for media transcoding and processing in modern networks, as well as “best practices” and strategies for handling media in the future. In particular, the focus will be on technologies such as virtualization and Cloud- based service delivery, and the roles they play in providing a more scalable, flexible media transcoding platform.

2 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

Table of Contents

The Market Challenge: More, More, More Media ...... 4

Media Processing Requirements In A Modern Network ...... 5

Voice Quality Enhancements ...... 5

Support for the Latest Codecs ...... 5

Support for Video Codecs ...... 5

Scalability ...... 6

Support for New Standards ...... 6

Best Practices For Media Transcoding ...... 6

Modern Strategies For Media Transcoding ...... 6

Media Transcoding at the Network Edge ...... 7

Centralized Media Transcoding ...... 8

Cloud-Based Media Transcoding ...... 8

The Dialogic Family Of Media Transcoding Solutions ...... 8

Dialogic® I-Gate® 4000 PRO Media Gateway ...... 8

Dialogic® PowerMedia™ XMS ...... 9

Summary ...... 9

About Dialogic ...... 9

3 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

The Market Challenge: More, More, More Media Each year it seems smartphones and tablets get smarter, bigger and more powerful, which in turns drives consumer appetite for richer media communications. As mobile devices evolve, the result is more media traffic (particularly video) and more bandwidth constraints for telecommunications networks. The ability of CSPs to meet the demand for better, faster delivery of voice, video and new apps over mobile, fixed or wireless access networks – some with less than adequate bandwidth - will depend heavily on the capability of next-generation media processing platforms and their support for the wide variety of encoding methodologies.

There is a significant number of different voice and video encoding methodologies or codecs used in networks and devices. Codecs have been developed over the years to suit a variety of purposes; some have been designed to reduce bandwidth consumption (e.g., narrowband codecs), while others have been designed to deliver superior voice quality (e.g., wideband codecs). (See Figure 1 below for a sampling of narrowband and wideband codecs.)

fullband stereo Opus fullband MP3 AAC Vorbis super-wideband G.719 G.722.1C

wideband royalty-free, open-source AMR-WB free license, not open-source licensing fees, not open-source Quality G.722 Speex

narrowband AMR-NB iLBC G.711

bitrate (kb/s)

Figure 1 - A sample of narrowband and wideband codecs used today (Jean-Marc Valin – www.opus-codec.org)

As mobile communications evolve and new technologies such as WebRTC emerge, new and innovative codecs are also developed to support them. The proliferation of codecs places greater demand on CSPs to support the interworking of both new and legacy codecs in their networks.

The process of converting one encoding methodology to another is called transcoding, and media gateways and media servers can use software-based or Digital Signal Processing (DSP) approaches to perform this task. Both software- and DSP-based transcoding approaches have their benefits and drawbacks:

• Hardware-based transcoding provides fast processing and high scalability, but it can take months or even years to accommodate and test new codecs, depending on the underlying equipment vendor’s roadmap and resources. • A software-based approach may require more CPU resources, but new codecs and thus new services can be spun-up fast without needing to upgrade hardware.

Also, the processing power of modern commercial-off-the-shelf (COTS) servers is constantly improving, as is server virtualization technology. Taken together, they make the case for software-based transcoding more appealing.

Regardless, media transcoding is becoming not simply an operational imperative but a competitive benefit as well. The ability to support new codecs quickly allows CSPs to offer new revenue-generating services to their customers and provide superior voice quality across more applications and devices. Consider, for example, that the Opus audio codec released at the end of 2013 is one of the codecs supported for WebRTC applications. CSPs that cannot support the Opus codec might find themselves at a competitive disadvantage if their media transcoding infrastructure cannot support this and other WebRTC applicable codecs.

4 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

Media Processing Requirements In A Modern Network Voice Quality Enhancement Techniques The role of media transcoding is paramount to ubiquitously delivering end-to-end next Silence Suppression, Voice Activity Detection and Comfort generation services. However, CSPs should also look for other capabilities in a media Noise Generation processing solution to achieve superior sound quality and to support more calls across Marking and eliminating the silent periods between words the network. In addition to transcoding, media processing solutions in a modern network and sentences can reduce bandwidth consumption by should include: fifty percent or more. Modern media gateways and servers should be able to detect periods of silence and suppress • Voice quality enhancements those packets and inject the reassuring comfort noise at the far end to deliver the same call experience in half the • Support for the latest codecs bandwidth. • Support for video codecs Adaptive Jitter Buffer • Scalability Media gateways and servers should provide adaptive • Support for new standards correction to the play out of packets subject to IP transport impairments that cause variable delay in the packet arrival Voice Quality Enhancements time (jitter). Small buffers are used that provide smoother and more seamless media packet delivery. The introduction of technology and techniques to minimize the required bandwidth Packet Loss Concealment and address packet impairment effects inherent in IP networks is integral to VoIP High levels of packet loss can result in unacceptable service, communications. Silence suppression, Voice Activity Detection, Comfort Noise, adaptive so media processing solutions should have effective packet jitter buffering and packet loss concealment techniques are all important features to loss concealment (PLC) algorithms to replace the lost enable a richer user experience. packets in a voice stream in order for the sound produced to be natural and seamless. Support for the Latest Codecs High-definition (HD) voice codecs are used in Voice over LTE (VoLTE) and they are also of particular interest to enterprises and consumers because of their ability to deliver superior customer experience. Adaptive Multi-Rate Wideband (AMR-WB, also known as G.722.2), Internet Speech Audio Codec (iSAC), Internet Low Bitrate Codec (iLBC), and Skype’s SILK are examples of high-quality voice codecs. In addition, WebRTC, a game changing technology that is fast revolutionizing communications, utilizes Opus. Future-ready support for newer codecs on media gateways is critical for CSPs looking to expand their services portfolio.

Support for Video Codecs Video communications are notorious bandwidth “hogs,” so in order to reduce the amount of bandwidth that video consumes while preserving the quality of service, CSPs look to video codecs such as H.263, H.264 and MPEG-4 to compress and interwork video sessions between different devices such as smartphones, tablets, videophones and PCs/laptops. (See Table 1)

Network Bandwidth available Terminals Codecs 3G-324M 64 kbps Video handsets H.263, H.264, MPEG-4 3G wireless data 256-768 kbps Video handsets, smart phones H.263, H.264, MPEG-4 Broadband IP 768 kbps Soft client on PC, smart phones H.264 Enterprise 2-5 Mbps Soft client H.264 WiMax, LTE 2-100 Mbps PC, TV, portable devices H.264

Table 1 – Video codecs used in various network environments

The video codec and compression techniques employed will ultimately determine video quality. CSPs should therefore have a variety of video options available as part of their media transcoding solution.

5 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

Scalability With the anticipated, explosive growth of video in CSP networks, a scalable media transcoding platform is considered a must. Media transcoding in many networks today is embedded into existing hardware (e.g., media servers, media gateways, session border controllers) or, less frequently, deployed as a standalone function in the network. Whatever path CSPs choose to follow, their choices will need to support rapid scalability of media transcoding services, particularly during peak workloads.

Support for New Standards Already, the industry is looking to new architectures beyond LTE and IMS, such as LTE-Advanced and 5G, as well as new codecs such as H.265 and Opus. Media transcoding solutions in the future will need to adapt to this type of change rapidly -- a challenge when considering the prevalence of a hardware-based approach that often requires updates to be made directly to the deployed hardware.

Best Practices For Media Transcoding As CSPs struggle to meet the demand for broader codec support and more bandwidth-intensive communications, a comprehensive approach to media transcoding will play a larger role in their future success. We have identified some important best practices around media transcoding that CSPs should consider as they map out their media transcoding strategies for the near-term and longer term future.

Minimize the number of transcoding events. As media transcoding requirements increase, CSPs should strongly consider a centrally managed media transcoding solution. This approach can offer an advantage over embedding media transcoding in multiple border devices (e.g., session border controllers) because it results in fewer transcoding events between devices. With a centralized approach, CSPs can manage media transcoding workloads efficiently and seamlessly, as well as upgrade their network to take advantage of new codecs quickly.

Support the widest number of devices possible, and make it as invisible as possible. The more codecs a network supports, the more devices and applications it can support. This is increasingly important as device manufacturers, application providers and industry consortiums are rallying around new applications and standards. Equally important, consumers have strong preferences over the types of devices and applications they use, and the ability to support these devices clearly places CSPs in a strong position to acquire and retain customers.

Strive for end-to-end service continuity. CSPs must often rely on a variety of network and application partners to deliver services from one endpoint to another. Historically, CSPs have had little visibility into quality of service once a call leaves their networks. In the future, CSPs will need to provide assurances that quality of service levels are met, end to end. This requires both deeper visibility into routing decisions and the ability to transcode audio and video into a greater variety of codecs to reduce bandwidth and enable more options for alternate routes.

Modern Strategies For Media Transcoding Choosing the right media transcoding strategy for your network depends on a variety of factors, including network type (e.g., fixed, wireless), traffic requirements, services and existing legacy infrastructure. Three media transcoding strategies seen as viable for CSPs in the future are:

• Media transcoding at the network edge • Centralized media transcoding • Cloud-based media transcoding

Network architects have impassioned debates on how best to apply transcoding; however, in many cases a hybrid approach can help balance the desire for operational efficiency and cost with the need for rapid time-to-market.

6 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

Media Transcoding at the Network Edge The traditional approach to media transcoding remains an effective strategy for fixed network operators that are looking to extend the value of their current network infrastructure. For them, deploying media transcoding at the border makes sense for the time being, so long as they can effectively scale their media transcoding capacity. With some vendor solutions, adding capacity means adding more boxes, which can often increase network complexity and multiply transcoding events, in violation of the first “Best Practice” above.

There are several devices that can support media transcoding capabilities at the network edge:

• Media Gateways are often deployed at the network border between TDM and IP networks, where they transcode and packetize media as it enters/leaves the core IP network.

• Session Border Controllers (SBCs) are deployed at the network border between the core network and either peer or access networks. The SBC provides signaling interworking, routing and network protection, as well as media transcoding, in a single device.

• IP Transcoding Gateways provide a good approach to device-based media transcoding at the border, both in terms of scalability and performance. IP transcoding gateways are deployed in the network core to support both access and peer applications (similar to SBCs) and provide transcoding, transrating and trans-sizing in a purpose-built appliance. IP transcoding gateways can be deployed in a variety of ways, including: — Media transcoder in Evolved Packet Core (EPC) Networks to support 4G/LTE, Wi-Fi, HSPA, fixed broadband (cable, DSL), enterprise VPNs and Interconnect Border Control Functions (IBCFs) — Media transcoding in networks that support RFC 4117 — Media transcoder for Border Control Functions (BCFs) to support a de-composed approach that splits signaling/security and media processing/transcoding into unique roles

• Media Servers can be deployed for specific applications to not only handle transcoding services but also to provide functionality that includes tones, announcements, and voice and video conferencing. Media servers can be deployed in applications that include: — Media Transcoder in IMS Networks to support VoLTE, VoLTE supplementary services and Rich Communication Suite (RCS) service — Media transcoder for SIP Application Servers to support rich value-added services and business applications — Media transcoder for WebRTC applications — Media transcoder for Hosted Rich Media Services

Inter-IMS NNI Carrier A IMS Network

Mx (SIP) SIP IMS Core IBCF Carrier B IMS Network or IPX RTP RTP TrGW

Signaling Border Control Functions Media Topology Hiding | Address Translation | Transcoding

Figure 2 - An IBCF and Transition Gateway (TrGW) is one approach that can be used at the Inter-IMS Network to Network Interface to provide border control functionality such as topology hiding, address translation and transcoding. TrGW functionality is provided by the IP Transcoding Gateway.

7 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

A CSP may have dedicated infrastructure to support business services or unified communications separate from its consumer offerings and may use a different transcoding strategy depending upon the type of customer. The CSP may encounter its enterprise customers using a wide array of user devices deploying different codecs. It may make sense for the CSP to normalize the media format for the business services at the access edge, which would make for more efficient processing of a smaller, more manageable number of codecs by the unified communications core infrastructure. Regardless, while this “all-inclusive” approach is financially attractive to CSPs, future network requirements may favor a disaggregated approach that allows media transcoding to scale and evolve as a separate, centralized function.

Centralized Media Transcoding Moving the media transcoding from the network border into the core network allows CSPs to centrally manage media transcoding in their network. This approach offers a number of benefits versus disaggregated media transcoding resources, especially in terms of management and updates for new codecs, and is recommended for mobile networks. IP Transcoding Gateways are typically used in this capacity. Other benefits to a centralized strategy include lower costs and the ability to balance media transcoding resources effectively across the network to accommodate dips and surges in traffic.

Cloud-Based Media Transcoding As media transcoding requirements grow, the Cloud provides a compelling alternative strategy to hardware-based media transcoding. Dialogic pioneered the concept of “virtualized” media transcoding through its software-based media server and SBC solutions, which can be loaded on Intel-based servers or run in a virtual machine environment. Cloud-based media transcoding represents the next logical step in virtualization, allowing CSPs to scale infinitely on demand, allocate media transcoding resources seamlessly to different points of presence and implement new codecs faster in a single push. Also, other functionality can be virtualized in this capacity such as tones, announcements, and conferencing in addition to media transcoding.

The Dialogic Family Of Media Transcoding Solutions Dialogic has long been a recognized leader in media processing and transcoding for communications networks. Embedded media transcoding functionality can be found in its media server, integrated signaling and media gateway, IP transcoding gateway and SBC products. For scalable media transcoding applications we recommend the I-Gate® 4000 PRO Media Gateway hardware appliance or the virtualized software-based PowerMedia™ XMS. These Dialogic® platforms provide CSPs with flexibility to address a distributed transcoding, virtualized/Cloud transcoding or a centralized transcoding architectural approach.

Dialogic® I-Gate® 4000 PRO Media Gateway Dialogic® I-Gate® 4000 PRO Media Gateway The I-Gate 4000 PRO Media Gateway is a high-density, chassis-based appliance that can be deployed in a centralized model to support highly scalable audio transcoding requirements as well as at the network edge between TDM and IP networks.

The I-Gate 4000 PRO has robust, “carrier-grade” features that make it well suited for large-scale deployments:

• Any-to-any transcoding of voice, DTMF, fax and more

• Supports multiple call control services (B2BUA, third-party call control per RFC 4117) to address a wide variety of deployment scenarios

• Extensive codec support including G.711u/a, G.723.1, G.729a/b, GSM-EFR, iLBC, AMR-WB (G.7222.2) and Opus

• Software-upgradable for new codecs/features

• “Five nines” availability

8 Which Media Transcoding Strategy Is Right for Your Network? White Paper (Hint: It might not be the strategy you’re using today)

CSPs can deploy the I-Gate 4000 PRO MGW as a high-density media transcoding platform that supports up to 62,400 call legs. I-Gate 4000 PRO MGWs support scenarios requiring media interworking described in RFC 4117, “Transcoding Services Invocation in the Session Initiation Protocol Using Third Party Call Control (3pcc).” Transcoding resources can be controlled via SIP for applications requiring an RFC 4117-compliant transcoding server to support 3pcc when codec interworking is required between two SIP endpoints.

The I-Gate 4000 PRO can work with the Dialogic® ControlSwitch™ System, BorderNet™ SBCs, and IMS Application Servers or other IMS/VoLTE session control platforms to interwork media streams between IP and TDM networks.

Dialogic® PowerMedia™ XMS PowerMedia XMS is considered the industry’s first software-based media server, featuring built-in media transcoding and support for both audio and video transcoding. PowerMedia XMS can be deployed in a decentralized model on common-off-the-shelf (COTS) hardware, in a virtualized environment, or in the Cloud. Well suited for enterprises and small-to-medium carriers, PowerMedia XMS is a mid-density media server (up to 2,000 SIP sessions) that leverages years of transcoding expertise in a highly flexible footprint, with features that include:

• Software-upgradable codecs • Wide codec support for audio and video: G.711u/a, G.723, G.726, G.729a/b, GSM-FR, GSM-EFR, AMR-NB, AMR-WB (G.722.2), iLBC, Opus, H.263/+/++, H.264, MPEG-4, VP8 • Compatibility within the IMS architecture as a media resource function (MRF)

PowerMedia XMS is also available in a clustered configuration for high-capacity media transcoding requirements. In this configuration, PowerMedia XMS can be deployed as an MRF or as a media resource broker (MRB) to act as a central controller/load balancer for a cluster of MRFs. This model can be virtualized or extended into the Cloud for greater scalability and flexibility.

Summary With WebRTC, LTE-Advanced and 5G on the horizon, CSPs will need to find new ways to effectively handle the rising number of rich media sessions and devices in their network. In addition, CSPs must anticipate and accommodate more codecs as new technologies and standards are developed. New media transcoding strategies such as centralization, virtualization and Cloud-based delivery provide the scalability, agility and flexibility to meet these demands. Dialogic provides CSPs the flexibility to implement the most cost effective strategy for media transcoding with either a highly scalable hardware-based solution using the I-Gate 4000 PRO MGW or rapidly deployed virtualized solution using PowerMedia XMS.

About Dialogic Dialogic, the Network Fuel® company, inspires the world’s leading CSPs and application developers to elevate the performance of media-rich communications across the most advanced networks. We boost the reliability of any-to-any network connections, supercharge the impact of applications and amplify the capacity of congested networks. Forty-eight of the world’s top 50 mobile operators and nearly 3,000 application developers rely on Dialogic to redefine the possible and exceed user expectations.

To learn more about Dialogic’s media transcoding solutions and product roadmap, contact your local Dialogic representative or visit us on the Web at www.dialogic.com.

9 www.dialogic.com

For a list of Dialogic locations and offices, please visit: https://www.dialogic.com/contact.aspx

INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH PRODUCTS OF DIALOGIC CORPORATION AND ITS AFFILIATES OR SUBSIDIARIES (“DIALOGIC”). NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN A SIGNED AGREEMENT BETWEEN YOU AND DIALOGIC, DIALOGIC ASSUMES NO LIABILITY WHATSOEVER, AND DIALOGIC DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF DIALOGIC PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT OF A THIRD PARTY.

Dialogic products are not intended for use in certain safety-affecting situations. Please see http://www.dialogic.com/company/terms-of-use.aspx for more details.

Dialogic may make changes to specifications, product descriptions, and plans at any time, without notice.

Dialogic, I-Gate, ControlSwitch, PowerMedia, and BorderNet are either registered trademarks or trademarks of Dialogic Corporation and its affiliates or subsidiaries. Dialogic’s trademarks may be used publicly only with permission from Dialogic. Such permission may only be granted by Dialogic’s legal department at 6700 de la Cote-de-Liesse Road, Suite 100, Borough of Saint-Laurent, Montreal, Quebec, Canada H4T 2B5. Any authorized use of Dialogic’s trademarks will be subject to full respect of the trademark guidelines published by Dialogic from time to time and any use of Dialogic’s trademarks requires proper acknowledgement.

The names of actual companies and products mentioned herein are the trademarks of their respective owners. Dialogic encourages all users of its products to procure all necessary intellectual property licenses required to implement their concepts or applications, which licenses may vary from country to country.

This document discusses one or more open source products, systems and/or releases. Dialogic is not responsible for your decision to use open source in connection with Dialogic products (including without limitation those referred to herein), nor is Dialogic responsible for any present or future effects such usage might have, including without limitation effects on your products, your business, or your intellectual property rights.

Any use case(s) shown and/or described herein represent one or more examples of the various ways, scenarios or environments in which Dialogic® products can be used. Such use case(s) are non-limiting and do not represent recommendations of Dialogic as to whether or how to use Dialogic products.