October 9, 2012

Internetworking Telepresence and Videoconferencing

The power feature for the current generation of collaboration solutions is video. From  mobile apps to high-end immersive telepresence rooms, we expect high quality video and we expect our networking solutions (mobile, FTTH, terrestrial, satellite, etc.) to support it. Unlike other types of data that traverse networks (e-mails, web surfing, FTP), low-latency interactive video can be particularly burdensome and demanding on network resources. The relationship between video systems and the networks used to transport the signal can often be complicated and problematic. Your network had better be ready to accommodate the potentially massive traffic created by video in a way that doesn't compromise existing traffic and allows for quality videoconferencing sessions. 

In particular, immersive telepresence requires crystal clear high-definition video to maintain the illusion that participants are in the same physical space. Lost or delayed QoS network provider MASERGY, to see why so many video managed service providers resold or private-labeled MASERGY's network connectivity for video applications. "MASERGY has IP packets and/or packets that arrive out of sequence cause video codecs to seize up and display video artifacts on the screen and/or clipped sound that can annoy and jolt participants out of the sense of immersion. While most network operators (enterprise and carrier) have the ability to maintain exceptional quality on their own networks, they are more frequently connecting to other networks to enable high-quality inter-company telepresence and videoconferencing with partners, vendors and customers.

In trying to replicate the experience of a face-to-face meeting, poor video quality will always fail the human brain's perceptual test and the innate expectations that humans have with respect to interpersonal communications. Remote participants exhibiting jerky motion and visible screen artifacts can't help but create an unnatural experience.

Here are some options to keep your video looking good and your end-users immersed and happy:

Terrestrial MPLS Networks

Video's  sensitivity to transmission defects is why Quality of Service (QoS) is such a big issue for users and IT organizations. It's also why telepresence architects and video service providers use dedicated networks that leverage the traffic classification capabilities of Multi-Protocol Label Switching (MPLS). In an overlay MPLS network, video traffic can be segmented from other WAN traffic and/or prioritized over other non-delay sensitive traffic in a converged network scenario. This approach helps minimize packet loss, packet jitter and packet delay. Buying an MPLS service doesn't guarantee flawless performance because not all MPLS networks are equal. Many network topologies arise from acquisitions or mergers where the operator has inherited network components (core/edge routers, switches) of various ages from various vendors, which can limit performance. We interviewed Chris Carr, director of Video Markets at long been recognized as the gold standard for QoS among the 
world's most demanding video users," he said. "But we are also  very focused on adding new value to video applications like our new Business to Broadcast Connect service, our inbound off-net QoS functionality, and our optimized-for- H.264 SVC Limited Class of Service. These will not only preserve the value of our customer's investments today but build new value for those investments tomorrow."

MPLS over Satellite

The words "satellite" and "MPLS" used to be mutually exclusive, but that is changing. Now it is possible to provide QoS network connections to any location at price points that keep getting closer and closer to terrestrial solutions. Emerging Markets Communications provides MPLS over satellite connectivity to oil rigs, humanitarian outposts, and remote government installations in 140 countries, including shipping, logistics, and on-site support. We asked Tom Luketich, vice president of video services, why so many folks were starting to run their video connections over satellite. "We are providing HD video conferencing and telepresence to places that are physically hard to reach by any other means, including conventional telecommunications," he says. "We cross borders, war zones and political boundaries while preserving the high quality that is required by many of today's video devices. EMC's HD Connect is delivered as service and the ROI is often less than a single business trip." A dish as small as 2.4 meters can provide up to 45MBps of MPLS connectivity to a remote location and can be up and operational immediately versus the time required to trench and pull fiber or copper to a site.

The Internet

In recent years, several developments have acted together to drastically improve the availability of business quality videoconferencing over the public Internet. For smaller companies looking to dip their feet in the video waters without major network investments, a solution that works over the public Internet could be just the ticket. The following two factors in
particular have dramatically changed the videoconferencing playing field.

  • Better Internet Network providers have more and better peering points while the typical broadband connections offer more bandwidth up and down at better prices than were available just a few years ago.
  • Better Video Codecs and Error Correction Video vendors have developed advanced codecs such as H.264 SVC and error correction technologies, which improve the quality of video sent over best-effort, lossy networks like the Internet.

In particular, the H.264 SVC codec has shaken up the industry by proving that business class videoconferencing over the public Internet is possible and affordable.

Cellular, 4G, and LTE

Today's mobile networks offer higher upload and download speeds than ever before. 4G LTE (the fourth generation of mobile network standards) is over 10 times faster than 3G. Root Metrics conducted a test comparing AT&T and Verizon download speeds in 15 different markets during Q1 of 2012 and found they were averaging 13.1 and 14.1 respectively and 6.0 and 7.4 Mbps for uploads. With this kind of bandwidth available on mobile devices, users will be expecting and using video-enabled apps. They will also expect these apps to work inter- and intra-company, inside and outside the firewall, anytime and anywhere. Smart organizations will support these workers with a proper inter-networking plan.

Inter-Company Visual Collaboration and Telepresence and Videoconferencing Exchange Providers

Ensuring that your data network is ready for video is only half the battle. Often people on disparate networks will wish to share video. Navigation between networks isn't trivial. In the next section we will explain the challenges that must be overcome when creating an internetworking strategy for video.

Telepresence and videoconferencing exchanges are the physical place where users on one enterprise and/or carrier telepresence and video conferencing network service can connect securely and reliably with users on one or more other telepresence and video conferencing networks. An exchange typically offers enterprise users a convenient, secure and high performance method for visual collaboration with telepresence and video conferencing users in another company, on another network or serviced by another Video Managed Service Provider.

Exchange providers connect together disparate networks while maintaining QoS so that video traffic can flow without compromising video quality. Many Exchange Providers provide additional services that simplify and facilitate inter-company telepresence and video sessions between partners, including the following:

  • directory services that schedule resources in other organizations
  • security services that implement policies to protect the networks and organizations that connect at the exchanges
  • diagnostic tools that can identity where problems arise across disparate networks and video network infrastructure elements.

Typical Inter-Company Visual Collaboration Challenges

Inter-company telepresence and video conferencing services need to overcome the following challenges and operational hurdles in order to provide a competitive offering for today's visual collaborators:

a.  Network Traffic Classification If two companies, with two different MPLS carriers and two different Video Managed Service Providers try to interconnect for a telepresence  session, the six companies will be faced with reconciling their disparate network traffic classification practices. However, as onerous as that sounds, many times the probability of congestion is low and the need for extensive concern is overblown if the network is fast, isolated from other 
applications or the telepresence/video environment isn't utilized much.

b.  Addressing Some solutions, such as the Cisco TelePresence System, requires the assignment of E.164 addresses to telepresence suites so that the Cisco Unified Communications Manager IP PBX can perform the session signaling, authorization and policy treatment of suite-to-suite sessions. Other solutions are IP-only and assume E.164-defined suites as ISDN-attached calls. Session border control appliancesare appropriate for allowing public IP addresses and private IP addresses and SIP URI-defined to participate freely. Many Cisco users have learned to configure their IP PBXs to correctly process SIP or H.323 session requests involving TelePresence suites.

c.    Security Session security is a concern whenever senior corporate officers from multiple companies gather and when all communications occur over networks, which is what happens in many inter-company telepresence sessions. Inter-company telepresence and video conferencing security needs to assure privacy of communication and control access. Well-known high performance encryption/decryption  implementations can assure privacy, and so can leveraging SBC infrastructure that prevents unintended traffic flows through firewalls but allows properly conforming SIP and H.323 session flows to pass cleanly.

d.    Directory, Reservation, and Resource Scheduling Directories provide a discovery service where users and administrators discover which partners have a telepresence or visual collaboration environment/endpoint, where that capability is located, and can also reserve a session at some future time or initiate a session immediately. However, because of the topics discussed and the high levels of executives involved in many telepresence sessions, most 
user organizations have different levels of visibility and permission for different facilities. Some have implemented an automated reservation application that coordinates session resources--suites, catering, network operations--which often runs on independent platforms such as Microsoft Outlook, Lotus Notes, Cisco TMS or myVRM.com. Managed Service Providers want to provide information that would simplify inter-company calls with their customers, but many are leery about releasing the contact details of the person responsible for telepresence and video conferencing services, fearing that information would help their competitors. Some providers offer directory and meet-me services including both web-based scheduling tools and a special concierge service that interacts with the technical and facilities resources in multiple organizations to get a technically challenging conference session scheduled which may include time for testing and troubleshooting if experience with the equipment and service providers involved is particularly low.

e.    Video Network Infrastructure Scheduling a call on the front-end between two or more organizations can create a resource problem on the back end. Whose video network infrastructure will be used? If the call requires a usage-based service like an ISDN dial-out, who pays? Some exchange providers require the customer to own the MCU or telepresence switch, and some providers include access to MCUs or telepresence switches as part of their service offerings.

f.    Multi-network Diagnostics and SLA Enforcement If a call between two networks experiences packet-loss, an access circuit generates bit-errors, and or an intermediary device is out-of-service, how do you know which provider to blame? How do you enforce SLAs for quality across multiple providers' networks? Some exchange providers provide tools that give an end-to-end view of session quality to identify problem responsibility.

Despite these challenges, many managed service providers are designing, reselling and implementing exchange services to facilitate the next wave of growth in telepresence and video conferencing. TPO

This article is brought to you in part due to the generous support of:


Excellent article. I would like to add that the recently ratified IEEE standard 802.1aq has great potential as a video ditribution infrastructure. The technology can provide multi-tenant separation as well as multi-service offering capabilities. Further work is underway within the IEEE to include traffic engineering capabilities such as those that exist within MPLS.

Nice article. In addition to above, RHUB (www.rhubcom.com) internetworking and video conferencing appliances is a very good option in order to conduct video conferencing, web conferencing, online meetings, webinars etc.

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