Cisco Cisco TelePresence Video Communication Server Expressway 관리 매뉴얼
Reference material
What are traversal calls?
A traversal call is any call passing through the Cisco 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 Cisco VCS but the media goes directly between the endpoints (or
between one endpoint and another Cisco VCS in the call route, or between two Cisco VCSs in the call
route).
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 Cisco VCS but the media goes directly between the endpoints (or
between one endpoint and another Cisco VCS in the call route, or between two Cisco VCSs in the call
route).
n
A call is “traversal” or “non-traversal” from the point of view of the Cisco VCS through which it is
being routed at the time. A call between two endpoints may pass through two or more Cisco VCSs.
Some of these Cisco VCSs may just take the signaling, in which case the call will be a non-
traversal call for that Cisco VCS. Other Cisco 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 Cisco VCS.
being routed at the time. A call between two endpoints may pass through two or more Cisco VCSs.
Some of these Cisco VCSs may just take the signaling, in which case the call will be a non-
traversal call for that Cisco VCS. Other Cisco 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 Cisco VCS.
The following types of calls require the Cisco VCS to take the media. They are classified as traversal
calls and will always pass through the Traversal Subzone:
calls and will always pass through the Traversal Subzone:
n
firewall traversal calls, where the local Cisco VCS is either the traversal client or traversal server
n
calls that are gatewayed (interworked) between H.323 and SIP on the local Cisco VCS
n
calls that are gatewayed (interworked) between IPv4 and IPv6 on the local Cisco VCS
n
for Cisco VCSs with Dual Network Interfaces enabled, calls that are inbound from one LAN port
and outbound on the other
and outbound on the other
n
a SIP to SIP call when one of the participants is behind a NAT (unless both endpoints are using
for NAT traversal)
n
encrypted calls to and from Microsoft OCS Server 2007 (requires the Enhanced OCS Collaboration
option key)
option key)
All such calls require a traversal call license each time they pass through the Traversal Subzone.
Traversal calls use more resource than non-traversal calls, and the numbers of each type of call are
licensed separately. The Cisco VCS has one license for the maximum number of concurrent traversal
calls it can take, and another for the maximum number of concurrent non-traversal calls. You can
increase the number of each type of call available on your Cisco VCS by purchasing and installing the
appropriate
licensed separately. The Cisco VCS has one license for the maximum number of concurrent traversal
calls it can take, and another for the maximum number of concurrent non-traversal calls. You can
increase the number of each type of call available on your Cisco VCS by purchasing and installing the
appropriate
.
Note that a non-traversal call on a Cisco VCS Expressway will consume a traversal license if there
are no non-traversal call licenses available.
are no non-traversal call licenses available.
Cisco VCS Administrator Guide (X6)
Page 277 of 295