Cisco Cisco TelePresence Video Communication Server Expressway 관리 매뉴얼
Call Types and Licensing
The VCS distinguishes between the following types of call:
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Unified CM remote sessions: these are "mobile and remote access" calls i.e.video or audio calls from
devices located outside the enterprise that are routed via the Expressway firewall traversal solution to
endpoints registered to Unified CM. These calls do not require any type of call license, although they do
contribute to traversal load.
devices located outside the enterprise that are routed via the Expressway firewall traversal solution to
endpoints registered to Unified CM. These calls do not require any type of call license, although they do
contribute to traversal load.
■
VCS traversal calls: these are standard VCS video or audio calls, including business-to-business calls,
B2BUA calls (for media encryption or ICE), and interworked or gatewayed calls to third-party solutions where
the VCS takes both the call signaling and the call media. Each call consumes a traversal call license.
B2BUA calls (for media encryption or ICE), and interworked or gatewayed calls to third-party solutions where
the VCS takes both the call signaling and the call media. Each call consumes a traversal call license.
Audio-only SIP traversal calls are treated distinctly from video SIP traversal calls. Each traversal call license
allows either 1 video call or 2 audio-only SIP calls. Hence, a 100 traversal call license would allow, for
example, 90 video and 20 SIP audio-only simultaneous calls. Any other audio-only call (non-traversal, H.323
or interworked) will consume a standard video call license (traversal or non-traversal as appropriate).
allows either 1 video call or 2 audio-only SIP calls. Hence, a 100 traversal call license would allow, for
example, 90 video and 20 SIP audio-only simultaneous calls. Any other audio-only call (non-traversal, H.323
or interworked) will consume a standard video call license (traversal or non-traversal as appropriate).
■
VCS non-traversal calls: these are standard VCS video or audio calls where the signaling passes through the
VCS but the media goes directly between the endpoints, or between an endpoint and another system in the
call route. Each call consumes a non-traversal call license. Note that Microsoft interoperability calls are
classified as non-traversal calls (even though the media does traverse the VCS).
VCS but the media goes directly between the endpoints, or between an endpoint and another system in the
call route. Each call consumes a non-traversal call license. Note that Microsoft interoperability calls are
classified as non-traversal calls (even though the media does traverse the VCS).
Each VCS also allows up to 750 concurrent non-traversal calls.
Note that:
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VCS defines an "audio-only" SIP call as one that was negotiated with a single “m=” line in the SDP. Thus, for
example, if a person makes a “telephone” call but the SIP UA includes an additional m= line in the SDP, the
call will consume a video call license.
example, if a person makes a “telephone” call but the SIP UA includes an additional m= line in the SDP, the
call will consume a video call license.
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While an "audio-only" SIP call is being established, it is treated (licensed) as a video call. It only becomes
licensed as "audio-only" when the call setup has completed. This means that if your system approaches its
maximum licensed limit, you may be unable to connect some "audio-only" calls if they are made
simultaneously.
licensed as "audio-only" when the call setup has completed. This means that if your system approaches its
maximum licensed limit, you may be unable to connect some "audio-only" calls if they are made
simultaneously.
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The VCS does not support midcall license optimization.
What are Traversal Calls?
A traversal call is any call passing through the VCS that includes both the signaling (information about the call) and
media (voice and video). The only other type of call is a non-traversal call, where the signaling passes through the
VCS but the media goes directly between the endpoints (or between one endpoint and another VCS in the call route,
or between two VCSs in the call route).
media (voice and video). The only other type of call is a non-traversal call, where the signaling passes through the
VCS but the media goes directly between the endpoints (or between one endpoint and another VCS in the call route,
or between two VCSs in the call route).
A call is "traversal" or "non-traversal" from the point of view of the VCS through which it is being routed at the time.
A call between two endpoints may pass through two or more VCSs. Some of these VCSs may just take the signaling,
in which case the call will be a non-traversal call for that VCS. Other VCSs in the route may need to take the media
as well, and so the call will count as a traversal call on that particular VCS.
A call between two endpoints may pass through two or more VCSs. Some of these VCSs may just take the signaling,
in which case the call will be a non-traversal call for that VCS. Other VCSs in the route may need to take the media
as well, and so the call will count as a traversal call on that particular VCS.
The following types of calls require the VCS to take the media. They are classified as traversal calls, require a
traversal call license, and always pass through the Traversal Subzone:
traversal call license, and always pass through the Traversal Subzone:
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Unified CM remote sessions (these do not require a traversal call license)
■
all other firewall traversal calls that are not Unified CM remote sessions, where the local VCS is either the
traversal client or traversal server
traversal client or traversal server
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calls that are gatewayed (interworked) between H.323 and SIP on the local VCS
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calls that are gatewayed (interworked) between IPv4 and IPv6 on the local VCS
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for a VCS Expressway with Advanced Networking enabled, calls that are inbound from one LAN port and
outbound on the other
outbound on the other
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a SIP to SIP call when one of the participants is behind a NAT (unless both endpoints are using ICE for NAT
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Cisco TelePresence Video Communication Server Administrator Guide
Reference Material