Polycom Enhances Its Portfolio with Support of the Telepresence

A POLYCOM WHITEPAPER
Polycom Enhances Its Portfolio with
Support of the Telepresence
Interoperability Protocol (TIP)
October 2011
A POLYCOM WHITEPAPER
Polycom Enhances Its Portfolio with Support of the Telepresence Interoperability Protocol (TIP)
Introduction
Interoperability between Polycom and Cisco has a long history.
Polycom voice devices and solutions, Polycom® HDX® endpoints,
and Polycom RMX® multimedia platforms have verified, standardsbased interoperability with the Cisco® Unified Communications
Manager (CUCM). As multiscreen telepresence systems became
more common in enterprises, customers started asking for
interoperability between Polycom and Cisco telepresence systems.
Polycom is strongly committed to standards and has long
established telepresence interoperability with vendors who support
the standard H.323 and SIP protocols.i Unfortunately, Cisco
telepresence systems relied on the proprietary Telepresence
Interoperability Protocol (TIP) that is compatible with neither SIPii
nor H.323. Responding to customer requests, Polycom added
support for TIP to its telepresence solutions and can now natively
interoperate with the installed base of Cisco TelePresence®
Systems (CTS) in the field. Most importantly, the simultaneous
support of SIP, H.323, and TIP protocols in Polycom’s solutions
offers the best protection of customer investments in telepresence
technology, allows more telepresence systems in the field to
interconnect, and drives greater use of telepresence.
Telepresence Interoperability Protocol (TIP)
TIP was created by Cisco as a proprietary protocol and is used
to connect Cisco TelePresence Systems (CTS); therefore,
interoperability between Cisco and other vendors’ telepresence
systems was initially impossible. Later, gateways were developed
to provide some level of interoperability but the audio and video
quality in multivendor configurations remained low because
gateways reformat video and audio streams. Gateways also add
latency (delay) to the connection, which decreases interactivity. By
natively supporting TIP in endpoints and media platforms, Polycom
avoids these pitfalls and provides a fully immersive telepresence
experience in mixed networks including those that include CTS
equipment.
On September 28, 2010, Cisco transferred TIP ownership to the
International Multimedia Telecommunications Consortium (IMTC),
where it is now managed by the TIP Activity Groupiii. TIP itself
has not changed as a direct result of the transfer, and diminishing
effort is expected to be spent on it going forward. Instead, Cisco
has joined Polycom, HP, LifeSize, and others in the IETF CLUE
Working Groupiv, to develop a versatile multiple-stream standard for
telepresence interoperability.
Implementation Scope
IMTC manages TIP versions 6 and 7; therefore, Polycom
implemented the latest TIP version 7 in Polycom telepresence
solutions.
Polycom Personal and Room Endpoints
• Polycom HDX endpoints (HDX 9006, HDX 8000 HD, HDX
7000 HD, and HDX 4500 systems)v
2
• Polycom Immersive Telepresence systems:
-- Polycom Open Telepresence Experience™ 300 (OTX™ 300)
version 3.0.2 or higher,
-- Polycom Open Telepresence Experience 100 (OTX 100)
version 3.0.3 or higher,
-- Polycom RealPresence™ Experience (RPX™) 200 and 400
version 3.0.2 or higher,
-- Polycom Architected Telepresence Experience™ (ATX™)
200, 300 and 400 version 3.0.3 or higher,
-- Polycom Telepresence Experience™ (TPX) HD 306M,
version 3.0.3.
Polycom® RealPresence™ Platform
• Polycom RMX® 2000 and 4000 media platforms version 7.6 or
highervi
• Polycom 7000 Distributed Media Application™ (DMA™) version
3.0 or higher
As part of the effort to ensure the best possible experience when
connecting Polycom and Cisco telepresence systems, Polycom
has added support for H.264 Main Profile to the already-supported
H.264 Baseline and High Profiles. While H.264 High Profile is used
on calls among Polycom telepresence systems and the Polycom
RealPresence platform, the H.264 Main Profile is used on calls that
involve Cisco CTS systems, in order to deliver the best possible
user experience. Explanation of the different H.264 profiles can be
found in the Polycom white paper “H.264 High Profile: The Next
Big Thing in Visual Communications.” vii
For best audio interoperability, Polycom has also added support
for the high-quality AAC-LD audio codec to its extensive list of
high-quality audio codecs that most prominently includes Polycom
Siren™ 22 technology. While Siren 22 and G.719 will be used on
calls among Polycom telepresence systems, AAC-LD will be used
on calls that involve Cisco CTS systems or infrastructure.
User Experience on Direct Telepresence
Calls
Direct calls (point-to-point calls) are calls between two
telepresence systems. The main challenge is the mapping of the
images among systems with one, two, three, and four screens (and
cameras, respectively). The Polycom HDX, Polycom OTX 100, and
Cisco CTS 1000 series are single-screen systems. The Polycom
RPX 200 and ATX 200 solutions have two screens. Polycom OTX
300, ATX 300 and TPX 306M solutions and Cisco CTS 3000
series are all three-screen systems. The Polycom RPX 400 and
ATX 400 solutions have four screens.
Scenario with Perfect System Capabilities Match
The full immersive experience is achievable when two connected
telepresence systems have matching capabilities. For example,
the two systems in Figure 1—Polycom OTX 300 and Cisco CTS
3000—both have three screens, and the monitors are using the
same 16:9 aspect ratio.
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Polycom Enhances Its Portfolio with Support of the Telepresence Interoperability Protocol (TIP)
OTX 300
CTS 3000
The RPX 200 system detects where in the room the active speaker
is located, and transmits the associated video stream to the CTS
1000 system. Video from the CTS 1000 system is displayed on the
right screen of the RPX 200 system.
The RPX 200 solution captures video in 4:3 aspect ratio and scales
it to 16:9 ratio before sending it to the CTS 1000 system. Due to
the scaling, the maximum video resolution is 720p (at 30 frames
per second). The RPX system also scales the video received from
the CTS 1000 system from 16:9 to 4:3 ratio before displaying it.
The TIP connection therefore consists of a video channel
(720p/30), an audio channel, and a content channel (video and
audio).
Point-to-Point Call with a CTS 3000 System
Figure 1: Video layouts: Polycom OTX 300 with CTS 3000
In this scenario, the TIP connection will have three video channels
(1080p) resolution at 30 frames per second (or 720p resolution
at 30 frames per second), three audio channels, and content
channel (video and audio). The three microphones on the OTX 300
provide stereo audio input and are mapped to the three mono audio
channels that TIP requires to provide directional audio.
Scenarios with System Capabilities Mismatch
The following subsections detail the behavior of systems when
there is mismatch of number of screens between two systems
in a point-to-point call. As noted earlier, the current TIP protocol
only supports 1 or 3 video streams. It does not support 2 or 4
multicodec systems. To address this, Polycom has implemented
the 2 codec system to function as single codec system and the 4
codec system to functions as 3 codec system.
The behavior of an RPX 200 system with a CTS 3000 system
is similar to that between the RPX 200 and CTS 1000 systems
described above. Specifically, it detects where in the room the
active speaker is located, and transmits the associated video
stream to the CTS 3000 unit.
Polycom RPX 400 System
Point-to-Point Call with a CTS 3000
Similar to the RPX 200 solution, the RPX 400 system supports
a 4:3 aspect ratio. When communicating to a CTS 3000 unit, the
RPX 400 solution will send 3 video streams to the CTS 3000
system. In this case no segment switching is supported, and this
means that one screen is never seen by the far end. See figure 3.
RPX 400
Polycom RPX 200 Solution
Point to Point Call with a CTS 1000 System
Not all telepresence solutions come in the same form factor and
the larger the mismatch of capabilities the more difficult it is to
deliver immersive user experience. Figure 2 shows an example of
a two-screen Polycom RPX 200 system connected to a singlescreen Cisco CTS 1000 system. To complicate the matter further,
the RPX 200 screens have a 4:3 aspect ratio while the CTS 1000
screens have a 16:9 aspect ratio.
CTS 3000
RPX 200
Figure 3: Video layouts: RPX 400 with CTS 3000
Point-to-Point Call with a CTS 1000 System
CTS 1000
Figure 2: Video layouts: RPX 200 with CTS 1000
For a point-to-point call with a CTS 1000 system, the Polycom RPX
400 solution supports segment switching, but only for 3 codecs.
This means that based on the active speaker, the RPX 400 system
will transmit the associated video stream to the CTS 1000 unit. This
also means that one of the camera views is never sent to the CTS
1000 system. See figure 4 on next page.
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A POLYCOM WHITEPAPER
Polycom Enhances Its Portfolio with Support of the Telepresence Interoperability Protocol (TIP)
RPX 400
CTS 1000
Figure 4: Video layouts: Polycom RPX 400 with CTS 1000
Polycom OTX 300 Solution
Point-to-Point Call with a CTS 1000 System
For a point to point call with the CTS 1000 system, the Polycom
OTX 300 solution supports segment switching. Again this means
that based on the active speaker, the OTX 300 system will transmit
the associated video stream to the CTS 1000 unit. See figure 5.
OTX 300
TIP support in the RMX media platform allows TIP endpoints, such
as Cisco TelePresence Systems, to connect to the RMX platform
while standards-based systems continue to connect through H.323,
SIP, and ISDN/H.320. The RMX platform’s ability to transparently
interconnect endpoints using H.323, SIP, and TIP into full multipoint
conferences is an important step in the evolution of a true Universal
Bridge within the Polycom RealPresence Platform. Polycom
customers can now leverage existing Polycom endpoints and
infrastructure to connect to Cisco telepresence systems without
upgrading the installed base to support TIP.
Note that although Polycom HDX and immersive telepresence
systems support TIP, they will not use TIP when connecting to
Polycom RMX, that is, SIP or H.323 will continue to be preferred
protocols for communication within the Polycom solution. TIP will
only be used when Polycom HDX and immersive telepresence
systems communicate directly with Cisco systems (CTS, CTMS).
RMX Media Platform
In Figure 6, a Polycom three-screen telepresence system (for
example, an OTX 300 system) and a single-screen system (HDX
system) join the multi-party call on the RMX media platform via
standard H.323 or SIP while a single-screen CTS system (CTS
1000) and a three-screen CTS system (CTS 3000) join the
conference via TIP. RMX supports simultaneously SIP, H.323, and
TIP, and provides both the signaling and media translation.
CTS 1000
Figure 6: Multi-party telepresence call through the Polycom RMX media
platform
Figure 5: Video layouts: OTX 300 with CTS 1000
User Experience on Multi-Party Telepresence
Calls with the Polycom® RealPresence™
Platform
Multi-party calls (multipoint calls) include three or more
telepresence systems connected through a conferencing server
(bridge). The experience differs depending on the servers providing
the multipoint functionality, and this chapter describes scenarios
using Polycom RMX® and DMA™ solutions.
4
The RMX platform supports two modes for multipoint calls:
Voice-Activated Room Switching (VARS) and Room Continuous
Presence.viii A higher level application called Multipoint Layout
Application (MLA) controls the layout of all participants in a
multipoint call. In addition to supporting automatic layouts, the MLA
can be extended with user-defined layouts which can be applied
automatically or manually to give complete control to IT on user
experience.
In the VARS mode, the RMX platform distributes the video and
audio from the speaker’s site (entire room, not part of it) to all other
sites. The RMX solution performs all required video conversions to
deliver the best possible image quality to all participants’ displays.
When a participant starts speaking, he monitors at the speaker’s
site show video from the previous speaker’s site, that is, the layout
remains unchanged.
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Polycom Enhances Its Portfolio with Support of the Telepresence Interoperability Protocol (TIP)
The RMX solution and MLA work with any combination of
endpoints, from desktop to telepresence rooms, selecting the
optimal layout for each of the participants. The ability of RMX
systems to transcode and MLA to build layouts for a large variety of
endpoints allows for much greater flexibility—in comparison to the
direct call scenarios described above—especially when there is a
capability mismatch among telepresence systems.
In Room Continuous Presence mode, the Polycom Multipoint
Layout Application (MLA)ix for RMX generates the multipoint view
automatically following the general principles of Polycom immersive
telepresence multipoint, that is, all participants are “present” during
a multipoint conference.
In addition, the conference administrator can use MLA to configure
a custom-set view that includes only particular sites in the
conference. The CTS 1000 single-screen system will get the same
video layout as an HDX single-screen endpoint while a CTS 3000
system with three screens will get the same video layout as the
OTX 300 three-screen system.
Cisco TelePresence Multipoint Switch (CTMS)
CTMS supports both segment switching and room switching; both
are voice-activated and use video switching rather than continuous
presence. In segment switching mode, the audio and video from
the segment of the speaker is transmitted to all participants. A
segment is a part of the room that is captured by a single camera
and associated microphone(s); therefore, a three-screen system
has three segments.
In room switching mode, all audio and video from the room of
the speaker is transmitted to all participants. For example, if the
speaker is in a three-screen room such as the Polycom OTX 300
solution, the video from the three cameras and the audio from
all microphones will be distributed to all other participating sites.
Figure 7 depicts a multipoint call using CTMS.
Distributed Media Application (DMA)
In the Polycom RealPresence Platform, DMA load balances multiple
RMX media platforms and creates a virtual pool of multipoint
conferencing resources. DMA can also be used as SIP registrar:
Polycom HDX and immersive telepresence systems register with
the DMA platform which uses a SIP trunk to connect to CUCM.
While the DMA solution is not involved in processing TIP—it simply
forwards the SIP signaling and behaves transparently—DMA is very
important for functions across Polycom telepresence systems, and
is therefore required in mixed Polycom immersive telepresence –
Cisco CTS networks. For example, content sharing based on the
ITU-T H.239 standard is supported across Polycom immersive
telepresence and other standards-based systems, and the DMA
platform supports the functionality. Cisco CUCM however does
not support H.239 and consequently systems registered directly
with CUCM do not provide the content sharing functionality.
Registering the immersive telepresence systems with the Polycom
DMA platform guarantees that well-established functions such as
content sharing continue to work in the telepresence network, while
the SIP trunk to CUCM allows Cisco CTS systems to participate,
with some limitations. Since the DMA solution is transparent
towards TIP, content sharing implemented within the TIP protocol
is also supported. By offering both standard-based H.239 content
sharing and TIP-based content sharing, Polycom’s telepresence
interoperability solution best protects customer investments in both
Polycom and Cisco technology.
Multi-Party Calls with Cisco Infrastructure
Through the support of the TIP protocol, Polycom HDX and
immersive telepresence systems can connect to the Cisco
TelePresence Multipoint Switch (CTMS) or the Cisco Telepresence
Server, and participate in multi-party calls.
Figure 7: Multipoint call through CTMS
The Polycom TIP-enabled HDX or immersive telepresence
endpoint is registered with Cisco Unified Communication Manager
(CUCM) and leverages its dial plan capabilities. Polycom HDX
and immersive telepresence rooms can join a meeting on CTMS
through dialing in or through CTMS dialing out to all participating
systems.
Unlike the Polycom RMX platform, CTMS requires a separate
gateway to connect to any telepresence system that does not
support TIP. The disadvantages of adding a gateway to the
configuration were already addressed earlier in this paper.
Another difference between CTMS and the RMX platform is that
CTMS only supports 1- and 3-screenx systems while the Polycom
RMX solution supports 1-, 2-, 3-, or 4- screen systems.
A third difference is that CTMS supports room switching and
segment switching modes while the RMX solution supports Room
Switching and Room Continuous Presence modes. Note that if a
Polycom immersive telepresence system connects to CTMS, the
segment switching functionality is available through CTMS.
The fourth difference is architectural: CTMS is a closed platform
that has limited calendaring and reporting APIs, and those require
a special license to use. In contrast, the RMX media platform
provides open, feature-rich APIs that allow seamless integration
with calendaring, reporting, and other applications from multiple
vendors.
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Polycom Enhances Its Portfolio with Support of the Telepresence Interoperability Protocol (TIP)
Cisco Telepresence Server
The Cisco Telepresence Server is the former Tandberg
Telepresence Server and provides—in addition to TIP—native
support for Polycom telepresence systems and endpoints, as well
as other standards-based (H.323 and SIP) systems. Therefore,
Polycom HDX and immersive telepresence rooms can connect to
the Cisco Telepresence Server using TIP signaling or using H.323
(although the experience is more limited that way). Figure 8 shows
a multi-party call on Cisco Telepresence Server.
Figure 8: Multi-party call through Cisco Telepresence Server
The Polycom TIP-enabled HDX or immersive telepresence
endpoint is registered with Cisco Unified Communication Manager
(CUCM) to leverage its dial plan capabilities. HDX and immersive
telepresence systems can dial in or the Cisco Telepresence Server
can dial out to them.xi
The difference between The Cisco Telepresence Server and the
RMX platform is mainly one of scalability. Cisco Telepresence
Server 7010 is not scalable and supports a maximum of 9 screens
in total, which is sufficient for 3 systems with 3 screens each but
not sufficient for a multipoint call of 4-screens systems such as the
Polycom RPX 400 solution. This leads to the need to use Cisco
Telepresence Server MSE 8710, which is a blade in the expensive
MSE 8000 chassis. Through an upgrade, the blade version can
support a maximum of 16 screens in total, which is equivalent to
5 telepresence rooms with 3 screens each, or 4 RPX 400 rooms.
The Polycom RMX platform is much more scalable. Each CTS
screen takes a 720p30 port; therefore, the RMX 2000 solution
can support 40 screens while RMX 4000 solution can support 80
screens.
Cisco Telepresence Server supports a maximum video resolution
of HD 720p—the same as in the Polycom RMX platform. Audio
quality to standard-based Polycom systems is limited to G.722.1
Annex C (14 kHz), while the RMX media platform supports Siren
22 (22 kHz) technology. However, if Polycom HDX or immersive
telepresence systems connect to Cisco Telepresence Server
through TIP, they use AAC-LD that delivers better audio quality
than G.722.1C Annex C.
6
Content Sharing
TIP allows for sending content over separate video channel and
separate audio channel. Polycom immersive telepresence and HDX
systems receive video and audio content and display the video in
the content display (second monitor) similar to the way it is done
in H.323/H.239. The incoming content audio is mixed with people
audio.
Content fed into Polycom immersive telepresence and HDX
systems through a VGA connection is sent through TIP to the far
end. However, TIP limits the content quality to a low frame rate of 5
frames per second and XGA resolution (1024x768 pixels).
Cisco CTS systems use WebEx extensively for collaboration.
Polycom immersive telepresence and HDX systems cannot
participate directly in WebEx sessions but there is an easy
workaround to send WebEx content from the HDX/immersive
telepresence side: the user can run WebEx on a laptop and use
the VGA connection to share the laptop screen with the remote
site. Naturally, Polycom immersive telepresence and HDX solutions
will display WebEx content from the far end if it is sent as video
content. Like any other content, the WebEx image is displayed on
the second display while content audio is mixed with people audio.
As discussed above, registering the Polycom HDX and immersive
telepresence systems, as well as other standards-based
telepresence systems, to the Polycom DMA platform—and using
a SIP trunk between DMA and CUCM—offers proper functioning
of the H.239 content sharing that is supporting in all video
systems, except Cisco CTS. This deployment approach is strongly
recommended.xii
Migration Path to TIP
Polycom HDX systems—which meet the hardware requirements—
require a software upgrade and a TIP software license to support
TIP. Immersive telepresence rooms require a software upgrade,
a TIP software license, and a Polycom Touch Control intuitive
graphical interface.xiii
Since immersive telepresence rooms such as the Polycom OTX
and Polycom RPX systems currently support stereo audio, these
rooms need to have the audio inputs calibrated to support the 3
mono audio streams required for TIP. The immersive telepresence
upgrade therefore requires a trained technician to visit the site.
RMX 2000 and 4000 media platforms must have MPMx media
blades to support TIP; these RMX platforms require only a software
upgrade to version 7.6 or higher and a TIP software license to
support TIP. The MLA application version 3.0.3 or higher is required
to create layouts including Polycom immersive telepresence and
Cisco CTS systems.
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Polycom Enhances Its Portfolio with Support of the Telepresence Interoperability Protocol (TIP)
Conclusion
Polycom is always listening to the market. Users of non-standard
telepresence systems from Cisco have told us they are challenged
by being locked into closed platforms that limit their ability to
communicate with colleagues, partners, and customers using other
platforms. They have also told us that they feel constrained by their
inability to integrate these closed systems into multivendor UC
environments.
In response, Polycom embarked on a substantial development
and testing effort to overcome these limitations by extending
our traditional open-standard support to include a non-standard
telepresence protocol (TIP) across our entire line of HD video and
telepresence systems and the Polycom RealPresence Platform.
The Polycom RealPresence Platform uniquely enables customers
to connect using any UC device they choose, regardless of
platform, and gives those who are in non-standard telepresence
environments the a path to natively integrate with the major UC
environments. It allows users of Cisco TelePresence to connect
to hundreds of millions of users of open standards-based
telepresence, voice, and video conferencing systems worldwide.
References
i
“ Polycom, Internet2, OARnet Provide First Public Multi-Vendor
Telepresence Interoperability Demonstration Reinforcing Importance of
Industry Standards” http://www.polycom.com/company/news_room/
press_releases/2009/20091007.html
ii Cisco has recently added SIP to its CTS systems (software version 1.7.4).
However, the SIP implementation only allows single-screen interoperability
and does not support a content channel (for content sharing). TIP is
therefore still required to get the full immersive telepresence experience
with a CTS system.
iii
IMTC TIP Activity Group, http://www.imtc.org/activity_groups/tip.asp
iv IETF CLUE Working Group, http://datatracker.ietf.org/wg/clue/charter/
v
TIP is supported in software version 3.0.2 (or higher) for Polycom HDX 9006,
HDX 8000 HD (hardware version B), HDX 7000 HD (hardware version C),
and HDX 4500. Protocol selection (TIP, H.323, or SIP) is performed on a
call-by-call basis, not port-by-port. Therefore, the internal multipoint function
(embedded in the endpoints) does not allow mixing TIP and H.323/SIP/ISDN
calls.
vi MPMx media blade is required for TIP support
vii H.264 profiles are described in the Polycom white paper “H.264 High Profile:
The Next Big Thing in Visual Communications.” http://www.polycom.com/
global/documents/whitepapers/h264_high_profile_wp.pdf
viii
About the Authors
This white paper is the product of joint research and work
conducted by Stefan Karapetkov, Robert Williamson, Eran Decker
and Grace Hu-Morley. Many thanks to Jeff Rodman, Roger
Farnsworth, Stephen Botzko, Peter Huboi, Brian Phillips, and
Umesh Bhavsar for their valuable review comments.
“Segment switching” mode is not supported.
ix MLA version 3.0.3 or higher support Cisco CTS systems. Earlier MLA versions
only support Polycom telepresence systems.
x
When on a multi-party call with CTMS, RPX200 behaves like a single screen
system while RPX400 behaves like a 3-screen system. This means that one
screen from each RPX200 and RPX400 is never part of the call.
xi
HDX v3.0.3.1 supports Cisco Telepresence Server v2.2 and CUCM v8.5.
xii Deployment Guide is available here: http://support.polycom.com/
PolycomService/support/us/support/strategic_partner_solutions/solutions_
cisco.html
xiii The Polycom Touch Control graphical user interface solution enables users to
quickly initiate video conferences, free from complicated interfaces.
About Polycom
Polycom is the global leader in standards-based unified communications (UC) solutions for telepresence, video, and voice powered by
the Polycom® RealPresence™ Platform. The RealPresence Platform interoperates with the broadest range of business, mobile, and social
applications and devices. More than 400,000 organizations trust Polycom solutions to collaborate and meet face-to-face from any location
for more productive and effective engagement with colleagues, partners, customers, and prospects. Polycom, together with its broad partner
ecosystem, provides customers with the best TCO, scalability, and security—on-premises, hosted, or cloud delivered.
For more information, visit www.polycom.com, call 1-800-POLYCOM, or contact your Polycom sales representative.
Polycom Worldwide Headquarters
4750 Willow Road, Pleasanton, CA 94588
1.800.POLYCOM or +1.925.924.6000
www.polycom.com
© 2011 Polycom, Inc. All rights reserved. POLYCOM®, the Polycom “Triangles” logo and the names and marks associated with Polycom’s products are trademarks and/or service marks of Polycom, Inc. and are
registered and/or common law marks in the United States and various other countries. All other trademarks are property of their respective owners. No portion hereof may be reproduced or transmitted in any form
or by any means, for any purpose other than the recipient’s personal use, without the express written permission of Polycom.
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