Cisco Cisco TelePresence Video Communication Server Expressway 관리 매뉴얼
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Any H.323 or SIP call leg to/from a VCS Control through a traversal zone configured to use Assent.
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Any H.323 call leg to/from a VCS Control through a traversal server zone configured to use H460.19 in
demultiplexing mode
demultiplexing mode
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H.323 call legs between a VCS Expressway and an Assent or H.460.19 enabled endpoint
The VCS Expressway uses non-demultiplexed media for call legs directly to/from SIP endpoints (that is endpoints
which do not support Assent or H.460.19), or if the traversal server zone is not configured to use H.460.19 in
demultiplexing mode.
which do not support Assent or H.460.19), or if the traversal server zone is not configured to use H.460.19 in
demultiplexing mode.
Media demultiplexing ports on the VCS Expressway are allocated from the general range of traversal media ports.
This applies to all RTP/RTCP media, regardless of whether it is H.323 or SIP.
This applies to all RTP/RTCP media, regardless of whether it is H.323 or SIP.
On new installations of X8.1 or later, the default media traversal port range is 36000 to 59999, and is set on the VCS
Control (Configuration > Local Zones > Traversal Subzone). In Large VCS Expressway systems the first 12 ports in
the range – 36000 to 36011 by default – are always reserved for multiplexed traffic. The VCS Expressway listens on
these ports. You cannot configure a distinct range of demultiplex listening ports on Large systems: they always use
the first 6 pairs in the media port range. On Small/Medium systems you can explicitly specify which 2 ports listen for
multiplexed RTP/RTCP traffic, on the VCS Expressway (Configuration > Traversal > Ports).
Control (Configuration > Local Zones > Traversal Subzone). In Large VCS Expressway systems the first 12 ports in
the range – 36000 to 36011 by default – are always reserved for multiplexed traffic. The VCS Expressway listens on
these ports. You cannot configure a distinct range of demultiplex listening ports on Large systems: they always use
the first 6 pairs in the media port range. On Small/Medium systems you can explicitly specify which 2 ports listen for
multiplexed RTP/RTCP traffic, on the VCS Expressway (Configuration > Traversal > Ports).
On upgrades to X8.2 or later, the VCS Control retains the media traversal port range from the previous version (could
be 50000 - 54999 or 36000 - 59999, depending on source version). The VCS Expressway retains the previously
configured demultiplexing pair (either 2776 & 2777 or 50000 & 50001 by default, depending on upgrade path) and the
switch Use configured demultiplexing ports is set to Yes. If you do not want to use a particular pair of ports, switch
Use configured demultiplexing ports to No, then the VCS Expressway will listen on the first pair of ports in the
media traversal port range (36000 and 36001 by default). In this case, we recommend that you close the previously
configured ports after you configure the firewall for the new ports.
be 50000 - 54999 or 36000 - 59999, depending on source version). The VCS Expressway retains the previously
configured demultiplexing pair (either 2776 & 2777 or 50000 & 50001 by default, depending on upgrade path) and the
switch Use configured demultiplexing ports is set to Yes. If you do not want to use a particular pair of ports, switch
Use configured demultiplexing ports to No, then the VCS Expressway will listen on the first pair of ports in the
media traversal port range (36000 and 36001 by default). In this case, we recommend that you close the previously
configured ports after you configure the firewall for the new ports.
For example, in a SIP call from within an enterprise to an endpoint at home through a VCS Control/VCS Expressway
pair, the only demultiplexing that would occur would be on the VCS Expressway ports facing the VCS Control:
pair, the only demultiplexing that would occur would be on the VCS Expressway ports facing the VCS Control:
Enterprise
endpoint
endpoint
VCS Control
VCS Expressway
Home
endpoint
endpoint
Non-
demuxed
Non-
demuxed
demuxed
Demuxed
Non-
demuxed
demuxed
RTP ports
36002 36004
36000 36002
RTCP ports
36003 36005
36001 36003
However, an H.323 call from within an enterprise to an Assent capable H.323 endpoint at home through the same
VCS Control/VCS Expressway would perform demultiplexing on both sides of the VCS Expressway:
VCS Control/VCS Expressway would perform demultiplexing on both sides of the VCS Expressway:
Enterprise
endpoint
endpoint
VCS Control
VCS Expressway
Home
endpoint
endpoint
Non-
demuxed
Non-
demuxed
demuxed
Demuxed Demuxed
RTP ports
36002 36004
36000 36000
RTCP ports
36003 36005
36001 36001
If the VCS Expressway has Advanced Networking, it will still use the same port numbers as described above, but they
will be assigned to the internal and external IP addresses.
will be assigned to the internal and external IP addresses.
Firewall Traversal Configuration Overview
This section provides an overview to how the VCS can act as a traversal server or as a traversal client.
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Cisco TelePresence Video Communication Server Administrator Guide
Firewall Traversal